After a successful season racing an '08 Honda CBR1000rr with WERA in 2010 I decided it was time to try something different for 2011. This was based on several factors; first, after finishing 2010 with some regional championships under my belt I'd received a letter from WERA stating I was being advanced to 'Expert' racer status for 2011. To be even remotely competitive as an Expert, I had to have two things squared away at the very minimum - riding talent and reliable equipment. The talent part I'm working on, building seat time and riding hard whenever I'm on the track to continue learning and pushing the envelope further...but the equipment part was something that needed to be addressed, as the Honda was ultimately found to be lacking the reliability needed for racing.
By the end of the season I was already busy comparing the different liter bikes coming out for 2011 that could serve as a foundation for a solid racing platform. There were the Italian brands (which I've always liked aesthetically, but knew would be costly to buy and modify), and three of the big four Japanese manufacturers were standing fast with carryovers from 2010 (or in Suzuki's case, 2009). Honda - no thanks. Suzuki - had one for years, loved it - but wanted something different, something more advanced in design and compact. Yamaha? The crossplane crankshaft R1 certainly filled the role at the professional level, but I only ever saw a handful of them club racing and had been told they took quite a bit of work to get solid power from.
But there was one bike on the horizon, one that I'd spent months following the rumors and press releases for to see how the final product would turn out - the 2011 Kawasaki ZX10R.
Being no stranger to Kawasaki (I've owned everything from early 90's ZX11s to ZRXs to a ZX6rr), I knew they were capable of producing excellent motors, however the previous generation ZX10 had a reputation for being a handful to set up for racing due to elements inherent in it's design. For months the rumors were that Kawasaki had an all-new design coming out, this time with a chassis capable of performing at a top level without chattering itself to death and a motor that was supposed to set the new standard for Japanese performance against those pesky BMW S1000rr's...
By November 2010 photos and video of the new ZX10r had made their way over the internet, and at first glance I was nothing less then intrigued. The looks were aggressive and purposeful, the chassis and motor seemed practically race-ready, and as a bonus Kawasaki was including the first ever active traction-control system on a flagship Japanese sportsbike. Things were looking good, and I was starting to think that this would be the way to go.
But then January 2011 came along and a flaw was found; what was later said to be an issue with the valve float reared it's head in early production models and Kawasaki stopped the release of the bike to the public after only a handful of units were sold. I looked at this two ways - first, at least Kawasaki was being proactive and fixing the issue before customers had to deal with it themselves, and second, they were serious about making this bike perfect right out of the gate. Not shaken by the delay, I waited patiently for further developments and spent time in the interim building a lightweight twin racebike (SV650) to race until I had the Kawasaki in hand.
By March 2011 the valvetrain issue was addressed and Kawasaki once again cleared the ZX10R for sale to the public. New bikes began trickling into dealerships, and after seeing one in person for the first time at the New York Motorcycle Show I was completely impressed by the compact dimensions and build quality. Kawasaki had stepped up their game, and I was now anxious to race this bike.
Come May it was time to dive in and purchase it. The good folks at Cycle World of Cherry Hill, NJ were once again excellent to deal with, and even went out of their way to provide a late-release ZX10R which was produced after the temporary hold/recall. And so, with the bike finally in possession, it was time to get started with the build...
Before we begin, note that this build page consists of modifications performed to prepare my bike for racing; I take no responsibility if you perform any of these mods to your own bike, and I highly recommend you begin with the proper tools, basic mechanical skills and a workshop manual detailing procedures and torque specs before starting work on your own bike : )
MAY 25, 2011
Picking up the ZX10r, I decided to ride it home from the dealership to give it a shakedown run and get a feel for the layout and controls. During the 60 mile ride I noted of several things right away; first off, the motor was unbelievably smooth with minimal vibration - this was refined engineering that had the feel of a quality Swiss watch. Second, the stock final drive gearing was way too tall - the powerband started in earnest only a little more then halfway through the rev range, and with the stock gearing the power felt almost too friendly (which makes sense since this was initially sold as a streetbike). And finally, the chassis felt solid and planted with effortless turn-in....I had a feeling this bike could potentially handle better then the Honda had once properly set up.
Some observations about the overall design and engineering; the centrally located ram-air intake is large enough to swallow a squirrel or two, so feeding the airbox at speed shouldn't be an issue. The stock bodywork is very aerodynamic - there was minimal buffeting on the highway, though the upper edges of the windscreen vibrated at speed. Also, Kawasaki went out of their way with the mass-centralization theme; an example would be the exhaust can, which is slung low and tucked in with a collector box mounted just forward of it beneath the engine. The stock headers are constructed from titanium alloy, using a diameter and design that is reportedly 'race-ready' with just the addition of a slip-on exhaust can.
Here's the good stuff - traction control! On the Honda I used a piggyback Bazzaz system in an effort to modulate the power on corner exits and minimize wheelspin, but on the Kawasaki this feature comes standard. Sensors and phonic rings at the front and rear wheels measure rate of rotation, and combined with sensors for throttle position, gear selection and engine rpm the ECU takes measurements at a rate of 200 times per second to determine whether or not traction will be lost under power. In the event wheelspin is detected (or even anticipated, reportedly), the system cuts engine power just enough to allow the rear tire to regain traction. This is accomplished through a series of complex algorithms programmed into the ECU - very good stuff for a bike with the potential to push 180 hp with the modifications to come.
The view from the rider's seat. Simple enough, watch the LEDs wind across the top of the instrument panel to tell you where you're at in the rev range, with the LCD display relaying everything from MPH to gear selection. The Ohlins linear steering damper that's supplied however is not impressive - and the odd thing when I've purchased these from Ohlins before they've always worked well. This one seems to be valved very conservatively to keep less experienced riders from dialing it in too stiff and falling over in the parking lot. On the plus side this one can be revalved to work as originally designed, which is on the list of things to do. Suspension wise, the Showa 43mm big-piston forks that come stock up front feel great on the road, but for racing the internals will be replaced with Ohlins 30mm cartridges and the rear shock swapped with a TTX unit for even finer performance. The Nissan master cylinder will be kept (unless there's a need for change down the road), and the stock rubber brake lines will be changed to race lines for improved feel and fade resistance.
The magic switch on the left handlebar; pushing up on the button controls the level of power output, and pushing down controls the level of traction control enabled. I'm curious to see if this switch can set the ECU to a single combination and then be removed altogether.
The stock rearsets are adjustable for height, however Woodcraft rearsets will make their way on for strength and durability. The rear swingarm is well constructed and braced, and includes mounting points for swingarm spools as installed here.
MAY 30, 2011
Time for bodywork...
The first step for race-prepping a bike is to remove the stock bodywork, which includes all the amenities included for street riding (lights and mirrors). In the case of the ZX10r, removal of the stock bodywork is a relatively straightforward process as outlined here. First thing's first - remove the lower fairing panels. I've highlighted in red the locations of the 4mm hex bolts and quick-release fasteners you'll need to remove to take the lower fairing panels off. Note that you only need to remove the center quick-release fastener located underneath, as well as the two lowest fasteners in front of the radiator inside the panels (as shown in the center photo below). To remove the quick-release fasteners, simply push in the middle button with a tool (the 4mm hex wrench works fine) and then pull out the entire fastener altogether.
Once you've removed the fasteners, the fairing panels should be pulled down and outwards to disengage them from the upper fairing. Next, remove the black panel covers on either side of the upper fairing using a 4 mm hex wrench. Once you've removed the front and rear bolts, pull up on the center of the covers to disengage the plastic pin from the rubber grommet as circled in the right photo above, then remove the covers altogether.
Next, disconnect the electrical fasteners for the headlights, turn signals, etc that are located inside the right portion of the upper fairing, then unscrew the two 10mm bolts above each headlight as circled in the center photo above. Once done, the entire upper fairing / headlight assembly can be pulled forward and down for removal as a single piece, however be sure to place a towel on top of the front fender before doing this to protect it and give you somewhere to rest the upper fairing before the next step. Next, use a compact Phillips screwdriver to remove the mounting screws for the fuse box and voltage regulator bracket that are located in the left side of the upper fairing (four screws in all).
After disconnecting the fuse box and regulator bracket, you can remove the upper fairing / headlight assembly completely from the bike. Now it's on to the tailsection; first, remove the passenger seat and four 4mm hex screws as circled in the center photo above. The plastic side panels can then come off, exposing the bolts for the rider's seat and taillight assembly. Remove all of the bolts and screws as circled in the above right photo, including the screws securing the passenger seat latch. Next, disconnect all the electrical fasteners for the taillight, turn signals, etc. that are located inside the black plastic sheath in the rearmost portion of the subframe (see arrow), as well as the grey electrical connector for the tip-over sensor switch. Underneath the tail assembly you'll see two plastic quick release fasteners - remove these, then pull the entire fender assembly downwards and away from the bike. Note that after you remove the tail assembly, you'll have to unscrew the tip-over sensor switch from the plastic fender pan in order to remount it on the motorcycle. If you don't do this, the bike won't start unless you bypass the sensor (which I don't recommend doing since it's a great way to ruin a motor when the bike's on it's side).
If you've done everything correctly, here's what you'll be looking at after about 15 minutes : )
After reviewing the various options available, I decided to try out the new Hotbodies Racing 'World Superbike' spec bodywork for this build, which included a green pigment impregnated in the fiberglass gel coat.
Upon opening the box from Hotbodies I found that each of the bodywork pieces were carefully packed. In this instance the kit I purchased came directly from Hotbodies and had previously been used as a demo to showcase this new line of bodywork. This was a tremendous help as the panels had already been drilled and fitted, though if you need instructions on how to fit and install race bodywork check out the CBR1000rr build page on this website.
Here you can see the Hotbodies upper fairing in comparison to the stock piece. I like the fact that Hotbodies extended the ears around the windscreen with their design, as it seems to provide for a more secure mounting method for the windscreen.
I have to say I was very pleased with the overall fit and alignment of the bodywork; every panel fit in place as intended and lined up perfectly. What was even more impressive though was the flexibility of the bodywork - I could literally bend the panels back and forth in my hands without hearing fiberglass splintering. In the right photo above I'm bending the side of the bellypan in by over an inch with no issues whatsoever. My initial impression is that this bodywork seems pretty heavy-duty and should be able to sustain a considerable amount of abuse.
Here the side fairing panels and bellypan have been installed; note the excellent alignment of the pieces. The tail section came as a two-piece 'superbike' tail, requiring the use of a foam seat pad. As I'm not a big fan of those types of seats, the tailsection will be modified later on the accept the stock (more comfortable) seat.
And here is the bodywork after being installed completely. The green gel-coat, though not as glossy as the stock bodywork panels, is an impressive match for the OEM Kawasaki green and looks excellent. The overall fitment of this kit is top-notch, and although I didn't have to drill the pieces for this installation I did note that the mounting points molded into the pieces lined up spot-on with the bike's stock mounting points. Even better is the fitment of the bellypan with the stock exhaust and collector still in place, though I'd be apprehensive about running it that way since the clearance is very tight. This should be easily addressed with the installation of an aftermarket exhaust.
JUNE 13, 2011
After fitting the bodywork it was time address the next major component of the bike - the suspension. Although the stock suspension would be fine for street riding and general trackday use, the reality is that once you start pushing a bike hard in racing situations it becomes critical to have the suspension tailored for your specific weight and riding style in order to provide proper control and feedback. Variances in the spring rates and valving as well as sag, rebound, compression, preload and ride height settings are all factors in how a bike will feel and perform at speed and what level of confidence the rider will have in it.
For this build I decided once again to go with the good folks at Ohlins USA in Hendersonville, North Carolina to obtain the components I needed, namely a 30mm cartridge kit complete with tailored springs and valving for the front forks and a TTX triple-adjustable shock for the rear. I've used Ohlins suspension on a number of bikes in the past and my personal experience has always been that their components excel in performance when properly set up.
The first step in changing the suspension is removing the forks for shipment to the service center, which requires placing the front of the bike on a stand that supports it underneath the steering stem. For the ZX10r fork removal is easy, starting with taking off the front wheel and brake calipers and then loosening the bolts holding the forks to the triple clamps and stock handlebars to allow the fork tubes to be lowered downward and away from the bike. Note that you'll need a 'Motion Pro' type hex-tool to remove the front axle from the forks and wheel. Once finished, wrap the forks in several layers of bubblewrap, place them in a sturdy cardboard box and voila! - time to ship.
While waiting for the forks to be returned, it was time to move on to other facets of the project. First off was replacing the stock fairing stay with a lighter aftermarket unit that would save weight and be easier to repair or replace in the event of a crash. For this project I installed a 'Motoholders' fairing bracket as supplied by Rider's Discount. Installing the Motoholders bracket was simple; first, disconnect the instrument panel plug from the rear of the instrument panel and then unscrew the three 10mm bolts securing the stock fairing stay to the intake snorkle. Once done, remove the fairing stay and instrument panel together as a single unit.
Next, remove the three Phillips head screws from the back of the stock fairing stay securing the instrument panel to it, and then remove the instrument panel. Transfer the rubber grommets from the stock fairing stay to the Motoholders bracket, and then install the instrument panel on it reusing the stock Phillips head screws.
This above photo shows a comparison of the Motoholders fairing stay (in the middle) to the stock unit (on the bottom). Not only is the Motoholders bracket considerably lighter and smaller then the stock piece, it's more able to be repaired and/or bent back into position after a crash.
Finally, the Motoholders bracket as installed on the bike, ready for mounting the upper race fairing.
When installing the upper race fairing to the Motoholders bracket, I found that the mounting holes for the fairing lined up perfectly with the smaller, lower 'guide' holes on the Motoholders bracket. As a result, I enlarged those holes with a drill bit to allow fitment of race fairing to that location.
I then addressed the seat situation; the 'superbike' seat pan was eliminated altogether and the rear tailsection modified to allow the stock seat to be used. For this I used a dremel tool, cutting away material in the tailsection as outlined in the photo above to allow clearance of the seat mount tabs. Once done, the stock seat installed perfectly and appeared factory-fit.
Next on the list was crash protection for the engine. In the past I've always used heavy-duty billet replacement engine covers to ensure durability and oil containment in the event of a crash, but for this project I decided to try something different. During the past year I'd heard about a British company named GB Racing that manufactured engine case guards made from (according to their website) 'High Impact, Reduced Wear, Injection Moulded 60% LONG GLASS fibre nylon 6.6 Engineering materials'. These covers reportedly provide excellent crash protection, and install easily over the stock engine case covers using longer replacement bolts. Given that the cost of the full three-piece GB Racing cover set was less then the cost of a single billet engine cover, I decided to give them a try. Overall, I was impressed by the solid construction of the these covers and am curious (though not too curious!) to see how they perform.
Installing the GB Racing covers was simple; just line the covers up and remove the stock bolts where the mounting points are, then use the supplied (longer) 8mm bolts to install the covers on the motor and torque to 11 Nm. All three covers fit perfectly and were installed in less then ten minutes.
Next it was time to replace the stock exhaust with a slip-on system to eliminate the exhaust valve, catalytic converter and collector box for both a weight savings and to increase exhaust gas flow for better performance. For this build I decided to go with the titanium 'Street Slayer' slip-on from M4; I went with this system primarily because of it's light weight and low-slung mounting position which seemed potentially less prone to crash damage then traditional 'passenger peg' mount canisters.
Removing the stock exhaust on the ZX10r is another easy process. First, unscrew the bolts to remove the thin black metal cover located between the exhaust canister and collector box, then unscrew the 10mm bolts holding the exhaust canister to the passenger footpeg. Next, loosen the clamp securing the canister to the collector box, and then pull the canister back to remove it from the collector box and bike altogether.
Next, take off the rider's seat to expose the servo motor for the exhaust valve. Now it's time to disconnect the cables from the exhaust valve to the servo motor; first, unclip the wire bracket securing the cables to the servo motor as shown in the left photo above. Next, pull back the rubber sheaths on the two cables (near the fuel tank) to reveal a pair of cable adjuster nuts; using an 8mm wrench, loosen the nuts to loosen the cables and provide sufficient play in them. Once loosened enough, unhook the cable ends from the hexagon shaped piece on the servo motor to disconnect them altogether. Leave the rest of the servo motor intact for now.
Next, feed the cables through the gap between the plastic tray and subframe spar and pull them underneath the bike so they're hanging free. Note that there's a round plastic clip attached to the battery tray which the cables run through; disconnect this clip with a screwdriver to free the cables. Once the cables have been removed, loosen the clamp securing the collector box to the exhaust headers and unscrew the allen bolt connecting the top of the collector box to the frame. Pull the collector box backwards and then remove it altogether it along with the cables as a single piece.
Here is a comparison of the stock exhaust canister, exhaust valve cables and collector box to the M4 system that replaces all of these pieces. Just a little bit of a weight savings here, no? : )
Finally, here's the M4 exhaust canister after being mounted. M4 includes a metal bracket that bolts behind the rearset mounting tabs on the frame to hold the exhaust canister clamp in place. This system is incredibly compact, and combined with the effectively-designed stock headers should provide a decent increase in horsepower once the fueling is properly dialed in.
JUNE 23, 2011
Continuing on, it's time to get to the nitty-gritty. First off, side stands are prohibited in racing so it's time to remove it. In the left photo above you can see the wire connector leading to the sidestand switch as well as the retaining clip holding the wire and the two bolts securing the sidestand to the frame. Disconnect the wire connector, unscrew the 8mm bolt holding the retaining clip and then remove the clip. Once done, replace the bolt where the clip was and then remove the two bolts holding the sidestand. Note that these bolts have red threadlock on them, meaning they'll take some force (and possibly some heat) to loosen. Also, be aware that once you do this modification your bike will need a swingarm stand to stay upright when parked. Make sure you have a stand handy before doing this mod unless you don't mind laying the bike on it's side when you're not riding it : )
After taking the sidestand off I cut the wires leading to the sidestand switch connector in the location pointed to in the right photo above. I then stripped the wires back about a 1/2" towards the connecter, twisted them together, and used heat shrink tubing to insulate the wires. The connector was then re-attached to it's plug to complete the circuit, telling the ECU that the sidestand is still 'upright' and allowing the engine to run when the bike is in gear.
Next, it's time to install the rearsets. Replacing rearsets isn't absolutely necessary for trackdays, but for racing I prefer something that'll stand up to considerable abuse, add a more crash protection and also provide better cornering clearance. For this build I'm using Woodcraft rearsets simply because in my experience they've been incredibly robust for racing applications; the solid mounted footpegs provide excellent feel and control and also act as a support slider in case the bike falls over or lowsides. Additionally, the footpegs offer decent grip without being too serrated which is a major consideration - serrated footpegs wear boot soles quickly and can cause serious injury in the event of a crash (ask me how I know).
To replace the left (shift side) rearset, first loosen the shifter rod located between the pedal and shift shaft linkage using a pair of 10mm open end wrenches. Next, remove the shift rod altogether and unscrew the two allen bolts securing the rearset to the frame. This allows the rearset to be removed as a single unit. Next, assemble the Woodcraft rearset making sure you use blue Locktite on every screw and bolt that you install; rearset bolts and shift rods have a tendency to back out over time, which always ends the day badly when you're on track and suddenly realize the pedal or footpeg is missing because they fell off. Also, dab a little waterproof grease on the pivot bearing for the new shift pedal before final assembly. Once done, re-attach the stock shift rod between the shift linkage and new heim joint, then bolt the new rearset to the frame (again using blue Locktite).
To replace the right (brake side) rearset, first disconnect the wire connector leading from underneath the seat to the brake light switch on the rearset; this can be found along the right subframe spar. Fish the connector out from under the seat and then pull it down towards the rearset. Next, unscrew the bolts holding the rearset to the frame and then turn the rearset around so the inside faces towards you. Next, as shown in the second photo above, remove the cotter pin and pivot (#3) which will be reused along with the 10mm bolt and large flat washer (#4) for the brake pedal. Note that the brake pedal return spring and brake light switch spring (#1 and #2) can stay on the stock rearset as they're no longer going to be used. Next, assemble the Woodcraft rearset (again using blue Locktite on the bolts and a dab of grease on the pivot bearing) using the aforementioned stock parts. Bolt the rear brake master cylinder and reservoir to the rearset, and then secure the rearset to the frame. Note that the height for both rearsets and footpegs (as well as the shifter toepeg position) can be adjusted for personal preference - get a feel for the rearsets and pegs in different positions to determine what work best for you.
Since this bike is going to be dyno-tuned and custon mapped for fuelling, next on the list is eliminating the KLEEN system (Kawasaki clean air system, also referred to as a PAIR or 'air-injection' system in other applications). KLEEN is a mechanical system that introduces fresh air from the airbox to the exhaust via a set of reed valves; the fresh air promotes a complete burning of residual fuel within the exhaust, which is a good practice environmentally speaking. The problem is, this fresh air also throws off air/fuel ratio readings during dyno-tuning, preventing proper readings and correct tuning. As a result, for use on an 'off-road' only racebike, it makes sense to eliminate this system altogether. Shown above is a photo of the KLEEN eliminator kit as obtained through Kyle Racing; these machined plates will allow the removal of the KLEEN injection system from the valve cover.
To remove the KLEEN system, the fuel tank must come off the motorcycle. To take the tank off the ZX10, first remove the plastc side panels located between the tank and the frame. These are secured with two allen bolts and a pair of molded pins held by rubber grommets. When removing the panels, take your time and be aware they have to be slid slightly forward when taken off to clear mounting tabs that are welded to both sides of the fuel tank. Once the panels have been removed, unscrew the two 10mm bolts securing the steering damper bracket and plastic cable guide to the frame and move them forward so the tank can be lifted, then unscrew the two allen screws securing the top plastic cover of the tank. Next, left the plastic tank cover straight up disengaging it from the two rubber grommets.
Finally, lift the fuel tank and disconnect the wire connecter at the rear for fuel pump, then disconnect the fuel line coupling and two breather/overflow tubes from underneath the tank. Next, unscrew the two bolts holding the bracket for the tank to the frame and lift the tank and bracket together as a single piece to remove them.
After the tank is taken off, disconnect the four fuel injector connectors as shown in the photo above (#1), then the fuel line coupling (#2). Next, lift the thin aluminum mounting bracket holding the connector assemblies to the airbox as shown (#3), and finally disconnect the two rubber tubes (#4) for the airbox overflow and breather lines.
For your reference, to disconnect the fuel couplings just use a small flat-blade screw driver to pull the square edge of the connector away from the coupling, then take the coupling apart.
Underneath the airbox towards the rear are two screws holding clamps that secure the rubber boots from the airbox to the throttle bodies; loosen these screws enough to where the airbox can be lifted up off the throttle bodies with minimal resistance. Next, unscrew the eight Phillips head screws holding the airbox cover on (seven around the perimeter, one in the center), and then disconnect the rubber hose going from the left side of the airbox to the KLEEN air solenoid.
Here's the airbox with the cover removed. To take the airbox off entirely, disconnect the two wire connectors from underneath the ECU (as shown in the upper left photo) and then take the ECU off entirely. Finally, lift the airbox lower half up from the throttle bodies.
For your reference, here are the two wire connecters that need to be disconnected from the ECU to remove it...
...and here is the KLEEN solenoid and rubber hose coming from the airbox. Disconnect the wire connector to the KLEEN solenoid as shown above, then remove the hose and solenoid altogether.
Next, pull back the rubber mat on top of the valve cover to reveal the two KLEEN ports. Unscrew the two allen bolts from each, then remove the entire assembly. Once done, use a small Phillips head screwdriver to unscrew the reed valves from the cage assembly which will be reused as a gasket. In the above right photo, you can see one of the KLEEN units completely disassembled; only the lowest piece is retained to be installed with the new cover.
After removing the reeds, place the cage back into the valve cover as shown in the above left photo - this ensures an airtight seal. Next, place the new cover on top of the port and secure it with the supplied bolts, again using a dab of blue Locktite. Repeat for the second assembly.
Once you're finished the installed covers will look like this. Finally, block off the opening from the airbox to the rubber hose that went to KLEEN solenoid; as shown here, I used a rubber cap and wire clamp sourced from a local hardware store to block it.
Next, it's time to install frame sliders. Again, I'm using Woodcraft frame sliders simply because in my opinion they're some of the best available since they don't protrude too much from the frame causing them to potentially catch on a curb and flip the bike or tear a motor mount in a crash. Happily for this application no bodywork modifications were needed to fit the sliders, though if you do need to make a modification see the CBR1000rr build page on this website for step-by-step instructions on how to do so. But, in the case of this Kawasaki, all that's required is unbolting the screw cover from the right side engine mount, removing the left side engine mount bolt and installing the slider mounts and pucks as shown - easy peasy.
JUNE 25, 2011
After receiving a pair of nifty boxes back from Ohlins USA it was time to put the suspension on the motorcycle. First off, the front forks were reinstalled at an initial height of 10mm from the fork cap to the top of the triple clamp; this is a preliminary setting made according to the shop manual, and may very well change later on depending upon factors such as geometry changes necessitated by tire height. Here you can see the fork caps after the Ohlins cartridge kits have been installed. What's interesting about the 30mm kits is that unlike the 25mm kits I've used (which had both rebound and compression adjustments in each leg), the 30mm kit has only compression damping in the left leg and rebound damping in the right. This is perfectly viable since once the front end is bolted together, the entire assembly acts as a single suspension unit allowing the separate functions of each leg to work together for the entire front end.
After reinstalling the forks on it's time to put the Ohlins TTX shock on; what's nice about the Kawasaki is that once the fuel tank is removed the shock absorber can be easily replaced in a matter of minutes. All that's required is placing the footpegs on a set of fixed jacks as shown in the above left photo to remove the weight from the swingarm, then loosening the upper and lower shock mounting bolts. To replace the stock shock absorber, just pull it upwards through the subframe and then install the replacement shock lowering it back into the same space. Tighten the mounting bolts to 25 ft lbs of torque and you're done!
Here is a comparison of the stock shock absorber with the Ohlins TTX unit; note the inclusion of an external hydraulic preload adjuster with the Ohlins unit (black knob) and the ability to adjust length via the threaded clevis at the bottom. Also, note that given that this is a ZX10r, the shock assembly is actually installed upside down in comparison to this photo.
After installing the suspension it's time to have it set up to a baseline setting that will serve as a solid starting point. For this task I once again brought my bike to the highly skilled folks at Washington Cycle Works in Washington Township, Warren County, NJ. I've used WCW to set up my last six trackday and race bikes for a reason; their level of expertise and service is exceptional, and they do an outstanding job relaying solid information about how to make bikes work properly. If you're in the tri-state area and looking for a reliable shop to set up your track bike's suspension, or need tuning or other services/parts, these are the guys to go to.
Once the preload, compression and rebound settings are adjusted to a baseline, the next step for checking the suspension action would be to book some track time. But first, a few more details to sort out...
June 30, 2011
Control is everything on a racebike, and in order to have the best control the first thing you have to do is ensure the controls you're using work best for you. As I prefer the feel and adjustment of CRG 'shorty' levers (for two finger clutching and brake action), these are the next items to go on. Here is a comparison of the stock levers to the CRG levers - note that the CRG levers install in the stock locations with no modification, and are less prone to crash damage ending your weekend then longer levers.
Next, it's time to install a Kawasaki race kit 'oil catch tank'; this part assists with controlling the flow of engine oil going to the airbox via the breather tube under high engine RPMs (e.g. racing conditions).
Another benefit of the race kit oil catch tank is that it includes a new location for the voltage regulator, relocating it from the stock upper fairing mount to the left side of the engine. The only issue here is that one of the three-wire harnesses leading to the voltage regulator has to be lengthened in order to relocate the regulator; this harness leads to the black connector as shown in the left photo above. Note that the left (gray) connector has enough spare wiring to simply be re-routed to the new location.
After splicing the harness to the black connector and lengthening it approximately 12" using 10 gauge and 12 gauge wire (to match the OEM wires), it's time to prepare the mounting site. In the center photo above, the arrows show where the catch tank mounting brackets will be bolted and the circles point out two crankcase bolts with copper washers under them. Since copper washers are an indication there is fluid behind the bolt (oil), these need to be safety wired before being hidden away behind the catch tank. Mark the bolts and remove them, then drill the bolts with a 3/32" bit and re-install them with safety wire as shown.
Next, mount the catch tank to the brackets and then attach the harness connectors to the voltage regulator. Next, mount the regulator to the catch tank and connect the rubber hoses from the catch tank to the crankcase and airbox using the designated hose clamps.
The next detail to be sorted is the mounting of the tip-over sensor switch, which has to be relocated since the stock taillight assembly it was previously attached to has been removed. For this build I sourced a common lightweight aluminum 'L' bracket usually used in computer assembly and shaped it using a dremel tool as shown. Next, holes were drilled to allow mounting of the bracket to the subframe and tip-over sensor, and the bracket was bolted to the rear of the subframe as shown.
Another detail to address was the mounting of the remote preload adjuster for the Ohlins TTX shock; according to the instruction manual, this would normally be mounted to the bottom of the stock passenger footpeg at the muffler bracket, but since that was eliminated another mounting solution was needed. For this I used a piece of angle iron as shown, cutting it and grinding down the sharp edges. I then bolted the piece of angle iron to the inside of the subframe as shown, attaching the remote adjuster directly to it. I also used a dremel tool to cut a small passage in the right side of the plastic subframe pan to run the adjuster tube through. Once done it's a clean and crash resistant installation, and the adjuster knob can still be turned easily after a simple removal of the seat.
Since dyno-tuning is right around the corner it's time to perform the last modification to the air-intake by installing a BMC 'race' filter as shown in the left photo above. The BMC filter flows considerably more air then the stock filter, though given it's thinner material and higher flow rate (which potentially also allows more dirt to penetrate), I'd save this modification for track use only as opposed to everyday riding.
July 4, 2011
Next it was time to replace the stock handlebars with race-ready clip-ons. There are a number of benefits to installing clip-ons, including the ease in which replacement bars can be installed after a crash and the ability to customize the positioning of controls.
Here are the stock handlebars before removal - it's a good practice to use a marker or thin paint pen to make a small mark on the triple clamp showing the angle of the stock handlebars in relation to the triple clamp before removing them - this gives you a starting point to follow upon re-assembly. To remove the stock handlebars, unscrew the bar-end weights and then loosen the screws and bolts for the controls, removing the brake and clutch lever assemblies off the bars. Next, use a front-end stand to support the bike from underneath the steering stem, then loosen and lower the forks enough to provide clearance to slide the handlebars out from underneath the top triple clamp. Next, unscrew and remove the throttle tube assembly as a single unit, and remove the handgrip from the left handlebar. To do this I sprayed a small amount of WD-40 between the grip and the handlebar by inserting the small red tube supplied with the WD-40 between them, then slowly worked and twisted the grip until it came off.
Once the stock handlebars are moved, it's time to remount the forks and prepare the Woodcraft clip-ons for installation. The first thing I did to the clip-ons was drill holes in the bars at the same locations as the holes on the stock handlebars to allow re-fitment of the switch housings. Some people avoid doing this by simply grinding the nubs off the switch housings and bolting them onto the new bars, but I prefer to keep the nubs intact as the housings tend to spin when not held in place.
After the bars are drilled, the two-piece mounts for the clip-ons are bolted onto the fork tubes, then the bars are inserted and the controls re-mounted. Note that you should install the throttle tube assembly on the right bar before placing the bar in the clip-on bracket.
Next, it's time to upgrade the front brakes with aftermarket lines, upgraded fluid and race pads to improve feel and minimize fade.
For this build I'm installing a Spiegler brake line kit and Vesrah 'SRJL' brake pads. The first step for this modification is draining the fluid from the stock brake lines, removing the lines altogether and then taking the front calipers off. Be careful when draining and removing the lines as brake fluid is very caustic and will damage your paint if spilled on it.
After removing the calipers, I used a drill press to drill holes in the caliper body where the brake pad pins are installed; this allows me to safety-wire the brake pad pins as required for racing. After drilling the calipers, it's time to install new brake pads; for this build I'm using Vesrah SRJL pads, which are excellent pads for track use as they offer exceptional feel and longevity with minimal fade and awesome stopping power.
To install the new brake pads, first unscrew the brake pad pins from the caliper, and then pull the old pads out. Take the metal backing plates off the stock pads and transfer them to the new brake pads, then install the new pads in the caliper and screw the pins back in place. Note that these calipers are clean because this is a new bike, but if your calipers are at all dirty you should give them a thorough cleaning with warm, soapy water and a soft brush before installing new pads, paying particular attention to the pistons.
After the new pads are installed, remount the calipers and then route the new brake lines making sure they have sufficient play and clearance to allow for fork movement without rubbing, binding or stretching excessively. Because the left caliper includes a wire for the front wheel speed sensor, I chose to attach the left side brake line to the wire as shown, allowing both to flex together as a single unit. After the calipers and lines are installed, fill the system with a quality brake fluid and bleed the air out carefully from the top of both calipers and the master cylinder. I used Motul RBF 660 for this build, simply because of it's high wet and dry boiling points and proven ability to maintain fade-free performance under racing conditions.
With more work to attend to, now it's time to drain and flush the cooling system. Since Ethylene Glycol antifreeze is not allowed in racing (if spilled, it can cause havoc on the track surface because of it's very slippery nature), it must be replaced with distilled water and Water Wetter. To drain the cooling system, remove the drain bolt at the base of the water pump located on the left side of the engine as shown in the above left photo, then allow the coolant to drain into a pan. For this build I also removed the pump altogether temporarily after the coolant was drained in order to access an engine bolt with a copper washer tucked away behind the pump (see center photo above) so it could be safety wired. Once done, the pump was re-installed. I then unbolted the overflow bottle from the right side of the radiator and drained it completely before flushing it with clean water and remounting it.
After the antifreeze has been drained, fill the system with distilled water, run the bike for a minute or two, and then drain the system once more to get rid of any residual antifreeze - you'd be amazed how much residual coolant is left in there. Finally, fill the cooling system with distilled water and add a couple of ounces of Water-Wetter.
Since the radiator isn't inexpensive and can end your weekend if something punctures it, I also installed some cheap insurance in the form of a home made radiator guard; I've made these guards for years because they've proven themselves to prevent damage tot he radiator from stones and debris. To make the guard, simply source some 1/4" wire mesh from a local hardware store. Measure the height and width of the radiator, then cut the mesh to fit those dimensions, allowing about an extra inch of material around the perimeter. Fold the extra material over and then flatten it with a rubber mallet to prevent sharp edges. Once done, mount the guard to the radiator using zip ties and have piece of mind knowing your weekend won't end early because something punctured it!
July 5, 2011
After finishing the basic mods it was time to dyno-tune the bike to obtain the best power as configured and optimize the fuelling. For dyno-tuning I opted to go to Guhl Motors in Ephrata, Pennsylvania, based upon information I'd read that they'd been able to successfully de-restrict the bike entirely with just software modifications applied to the stock ECU. In stock form, the U.S. version of the ZX10r signs-off it's power at approximately 12,000 rpm due to noise and emissions regulations; this top-end power is held back via restrictions programmed into the ECU including changes to the ignition timing and openings of the secondary throttle bodies and exhaust servo valve. And the worst part is, word was these restrictions robbed as much as 15 peak horsepower from the U.S. version of the bike.
In addition to de-restricting the bike I was also told by Guhl Motors that they would be able to re-map the fueling directly to stock ECU to allow for changes to the air/fuel ratios programmed in, eliminating the need for a piggyback fuel controller such as a Power Commander or Bazzaz module. I found this intriguing as the concept of mapping the fueling directly to the ECU meant there would one less extra component I'd have to worry about failing.
Guhl Motors is a tuning shop that deals primarily with micro-sprint (dirt) racing, however since their race vehicles use motorcycle engines it turns out Guhl is very familiar with bike engines and their electronic systems; Guhl Motors was the first tuning shop in the country to be able to decipher the coding in the new ZX10r ECU, and after speaking with the owner Donald Guhl I was convinced they'd be able to set up the ZX10 correctly.
The first step in programming the ECU was fabricating a harness that would be able to communicate directly with the stock ECU in order to 'reflash' it, as shown in the left photo above. Once done, a baseline dynamometer run was performed to determine the current state of tune and power with no other modifications performed other then the M4 slip-on exhaust and BMC race air filter that were installed. The initial baseline run showed a maximum horsepower (HP) reading of 156.16 with a torque reading of 71.65 ft lbs as performed on a true-reading Dynojet Dyno, which was interesting to see as this was already 4 HP more then my previous Honda racebike had reflected after tuning mods were performed.
Next, the ECU was re-flashed with the factory restrictions eliminated. The results were astounding - the HP shot up to a peak of 170.87 with a torque reading of 71.55 ft lbs! This was a gain of almost 15 HP obtained simply by eliminating the factory restrictions programmed into the stock ECU.
(Click below for clips of the dyno runs)
Below is the stock ECU after modification. Guhl puts a label and unique serial number on every flashed ECU in order to identify it for future programming.
Finally, after a number of additional dyno runs were performed, the fuel maps were tweaked to optimize power and the air/fuel ratios throughout the RPM range. At the end of the day, when all was said and done, the bike produced a maximum reading of 171.24 HP and 71.97 ft lbs of torque with the fueling dialed in smoothly. The only thing left to do was to go to the track and test everything out to see where the bike stood. But first....
July 7, 2011
The last modification necessary before track testing would be to change the stock final drive gearing to something more suitable for racing; generally, you want to change the final drive gearing of your bike to allow it to rev out it's highest transmission gear at the end of the longest straight of the track you're racing. However, since I had no preliminary data to work with for this bike at any track, I decided to begin by simply changing the stock final drive gearing from 17/39 to 16/41, meaning a one tooth smaller sprocket was installed on the front (going from 17 to 16 teeth) and a two tooth larger sprocket was installed on the rear (going from 39 to 41 teeth). Changing sprockets is easy enough, though you need to have access to a compressor and airgun in order to remove the nut holding the front sprocket on. The first step to changing the front sprocket is removing the three bolts from the sprocket cover as shown, and placing a sturdy piece of wood or similar object between the holes in the swingarm and through the rear wheel to keep it from spinning.
After removing the sprocket cover, use a screwdriver and mallet to pry back the washer securing the front sprocket nut. Once done, remove the nut with an airgun, using the braced rear wheel to keep the chain from turning. After the sprocket nut has been removed, take the washer off, then remove the sprocket. The third photo above shows a comparison of the 16 tooth sprocket to the stock 17 tooth sprocket; note the lack of rubber damping rings around the aftermarket sprocket, which has no effect for this application.
Next, install the new sprocket, washer and nut, then tighten the nut accordingly and re-secure it by bending the washer tabs back over the sides. Finally, re-installed the sprocket cover.
For the rear sprocket, remove the rear wheel from the bike, unscrew the nuts securing the stock sprocket to the carrier, and then replace the stock sprocket with the aftermarket unit. For this build I'm trying out a 'Supersprox' sprocket in order to compare the fit, wear and performance to the all-aluminum sprockets I've used in the past. What's unique to the Supersprox sprocket is that the center portion is made from aluminum to minimize weight, but the outer-toothed ring is made of hardened steel to provide a longer service life.
Finally, I removed the sound-deadening rubber matting installed over and around the engine to allow for easier access and servicing as well as less clutter. Once the matting was removed, I installed heat shield underneath the fuel tank in order to limit the amount of heat transfer from the engine. The ensure the heat shield stayed in place, I cut the heat shield to size and then sprayed the underside of the tank with adhesive spray to promote a strong bond.
July 11, 2011
Time to test...
Click photo above for video of initial shake down runs at Mid-Ohio Sports Car Course
After months of preparation it was finally time to take the bike to the track for some shake down runs to see how it performed with the modifications made and to determine what else needed to be done. In order to get a good idea as to the bike's positive and negative aspects, it was necessary to go to a track with a layout that offered a wide array of challenges - the right combination of technical corners, elevation changes and straightaways where a motor could be wound out. In other words, the Mid-Ohio Sport Car Course in Lexington, Ohio.
Mid-Ohio is a challenging track that quickly reveals any issues with a bike due to it's complex nature and range of turns including those with decreasing radius, varying cambers and elevation changes. There's also a significant 'straightaway' section with a shallow kink that allows a bike to be wound out before ending in some serious braking.
Day one at Mid-Ohio provided three, twenty-minute sessions on track before the skies opened up with rain ending the day early. Those three sessions revealed quite a bit about the bike setup, however. First off, even with the lowered gearing the bike needed to be revved out significantly before the power came on in earnest; this wasn't a fuelling issue, but rather a characteristic of the engine. Simply put, this motor needs to be revved out like a 600 for decent corner exit drive, which took some getting used to after years of riding midrange heavy GSXR and CBR1000 literbikes that would launch you to the moon if you tried such shenanigans.
The second issue was the overall geometry setup; with the forks raised 10mm above the top triple clamp and the shock set at the stock length, the front end felt like it wanted to tuck under turn-in while the rear wanted to run wide on exit throttle. Lowering the forks to just 5mm showing over the triple clamp seemed to address the front tucking, but the rear still wanted to run wide.
The third issue was the shock setup, including rebound adjustment and spring rate; as shown in the first photo below, the rear tire was displaying wear consistent with improper rebound damping and too soft a spring, causing the rear tire to compress and skip as it worked too hard to make up for the lack of suspension. This would take some time to work out, as the condition worsened the following day after additional rebound adjustments were made without the benefit of having a different spring installed.
Day two at Mid-Ohio offered better weather and a full seven, twenty-minute track session to continue learning and setting up the bike. During this time a number of changes were made to try and improve the handling, including extending the shock length by 5mm to raise the rear and help finish turns, but by the end of the day I concluded a spacer would be required since the rear needed to be raised even further. To compound matters, the too-soft shock spring was continuing to cause problems with the rear end squatting too much under power, which contributing to the front running wide and forced me to ride more conservatively then I'd originally planned.
Additional conclusions reached were that the gearing was off since the bike was often in-between gears on certain sections and only winding out fifth on the longest part of the track (through the T6 kink). Also, a quick shifter became high on the list of things required along with a revalving of the stock steering damper, which proved itself to be utterly useless in controlling headshake as delivered.
July 22 - 27, 2011
After returning from testing at Mid-Ohio I was starting to grow concerned that the bike wouldn't be sufficiently set up for it's inaugural race weekend with WERA at the end July, as the issues that reared their head at Mid-Ohio prevented me from being able to push the bike hard enough to get a true feel for how it would act at speed.
A quick call to Thermosman Suspensions confirmed they'd be able to revalve the stock Ohlins steering damper to make it work properly, to which it was removed from the bike and shipped off for servicing. A couple of days later the damper was returned, remounted, and......the difference was unbelievable. Not only did the damper finally work properly, it also had a full range of adjustment as originally intended.
Next up was the installation of a quickshifter unit. Because there was no piggyback fuel module installed, a 'stand-alone' quick shifter was needed. Luckily I found that Bazzaz Performance was already producing such a unit for this bike - here is the Bazzaz quickshifter control box, wire harness and shift switch after first being opened.
To install the quickshifter, the first step is to remove the fuel tank and airbox as demonstrated earlier on this build page. Next, route the supplied quickshifter harness along the right side frame rail, and plug the four connectors into the coils as shown in the first photo above in order from left to right. Next, mount the control box on top of the battery with velcro, then plug the remaining connector into the stock harness as shown in the above right photo. Attach the ground wire from the Bazzaz harness to the ground bolt on the frame, then route the cable for the shift switch down the left side of the frame to the left rearset.
Next, remove the stock shift rod and replace it with the shift switch and supplied replacement (shorter) shift rod. Note that I had to cut approximate 10mm from the Bazzaz shift rod in order to make it fit with the Woodcraft rearset, which is no big deal as the rod is designed to be shortened as required. Once done, zip tie the harness and related wiring to secure points on the bike to prevent damage, then turn on the ignition key to ensure the power light on the control box operates. Quickshifter installation complete!
Next it was time to address the rear shock. A quick call to Ohlins arranged for the delivery of a spring one rate higher for the rear (going from a 120 to a 130 spring) to address the excessive squatting under acceleration. In addition, the shock was returned to the stock length and in its place washers were installed under the top clevis to increase the rear ride height. A trip to Lowes with the clevis in hand revealed that a 5/8" washer as shown in the left photo above fit perfectly and allowed for installation without any further modifications needed. Furthermore, each of these washers were approximately 2mm thick, making future adjustments possible in 2mm increments. As I wanted to start with 10mm of additional ride height in the rear, five washers were installed under the clevis and the shock remounted using the stiffer spring.
July 29-31, 2011
Time to Race !
After making ride height and spring adjustments to the shock it was time to take the bike back to the track to see if the changes were turning the bike in the right direction, no pun intended : ) For this it was time to go to Summit Point Motorsports Park in West Virginia for Friday practice and Sunday racing with WERA.
The practice day proved to be invaluable as it was immediately apparent in the opening sessions that the changes made had transformed the handling of the bike. Instead of running excessively wide on corner entry and exit on the throttle it was starting to track properly through turns, though still not perfect. An issue with the front being overly twitchy was resolved by flushing the forks with the top triple clamp, and the new rear Bridgestone BT-003 race tire looked absolutely perfect even after repeated sessions of hammering it.
With the bike starting to present signs of predictability it was time to push the pace. Finishing the practice day with laptimes in the low 1:19's, I discovered that the slipper clutch worked very well while downshifting from 5th to 2nd gear into Turn 1. I also discovered that the gearing was still too high, though with no additional sprockets on hand it was a setup that I'd have to live with for the weekend. Other minor issues included further adjustment of the rearsets and clip-ons, and as the seat time increased I found myself growing more and more confident with the overall platform. The handling (though not yet perfect due to continued understeer) was at least predictable and the power linear as I got used to revving the engine out. In addition, the brakes were excellent in their ability to scrub off speeds over 160 mph lap-after-lap with a mere two-finger pull of the lever.
Come Sunday it was time to race the bike for the first time. Although I knew it wasn't set up 'perfect' for what I wanted to do, I was confident enough with the setup that I felt I could start to push a bit harder at a race pace to see what else needed to be dialed in.
First race of the day was the Senior Superbike race, a combined race of 1000cc and 600cc bikes gridded by displacement. Starting from fourth on the second row, once the green flag dropped I was able to get enough feel from the clutch that I was able to slip it halfway decently and make my way up to third into Turn 1. As the race continued and the pace increased, I found that the bike still wanted to understeer on both corner entry and exit, though not so badly that I didn't want to push harder with each passing lap. Exiting Turn 10 on the final lap while in the lead, I simply didn't pull the trigger early enough to overcome the understeering and finished the race in second place after running wide, losing time and being passed at the line.....by eleven-hundredths of a second.
So second place it was. Which I have to say I wasn't too upset about, given that was my very first race on the bike : ) On the plus side, I'd gotten my laptimes down into the mid :18's, which so far was the fastest time I'd ever been able to circulate Summit Point. Yes, I was starting to wonder how the bike would perform when dialed in even better...
The second race was the Formula 1 (open class) race, which I started in seventh position and ended in sixth, again fighting understeer in just about every corner. What to do, what to do.....
Click above photo for onboard footage of the race
August 20, 2011
After reviewing some notes from the race weekend and reflecting on how the bike performed, it was time to tweak a few more thing to take care of both new and lingering issues. First with the new...
One of the minor issues when racing was that the throttle tube handgrip was literally sliding back and forth along the bar by a hair under 2mm; though it doesn't sound like much, when you're leaned over and trying to feed the throttle in smoothly it's quite the distraction having to adjust your wrist and hand movements for the excess throttle-tube play. In the above left photo you can see the amount of lateral play in the stock throttle tube. To alleviate this, I decided to install the Kawasaki race kit throttle. The race kit consists of six pieces (not including the mounting bolts); new upper and lower throttle housings, a 60 degree billet aluminum throttle wheel, a new throttle tube and a pair of matched throttle cables\ that are longer then stock.
The above left photo shows a comparison of the stock throttle cables (on top) to the race kit cables, which have to be longer as they'll be routed differently from stock. The above right photo shows a comparison of the race kit throttle tube (left) to the stock throttle tube; note that the billet wheel is also available in 65 degrees if needed.
To install the race kit throttle, remove the upper fairing, fuel tank and airbox, then remove the stock throttle tube assembly from the clip-on and disconnect the cables from the throttle body. Install the kit throttle tube onto the clip-on and route the new cables over the ram air intake, between the left fork leg and steering stem, and finally underneath the left frame rail to the throttle body. Contrary to the directions in the race kit manual, I ended up positioning the kit throttle tube housing with both cables underneath the brake lever to allow sufficient cable clearance when turning the handlebars lock-to-lock.
Here's the race kit throttle after installation; no more lateral play and less twisting needed - nice.
Another issue was the inability to use a wider-range of rear sprockets due to the stock chain being too short, which currently allowed only a maximum of +2 teeth on the rear before running out of slack. As a result, it was time to install a longer chain. For this I went with the EK MVXZ race chain in my favorite new color, Kawasaki green : ) I used these chains in other applications and they've proven themselves time and time again to be reliable.
Installing a new chain is easy, however you need the right tools to do the job properly. A 'Motion Pro' chain tool and a Dremel tool are what I use, though RK also makes a chain tool that's excellent. To start, grind off one of the roller pin ends, then use the chain tool to push the pin through and the old chain can be taken apart. Next, connect one end of the new chain to the old chain (for this I used a small piece of safety wire) and pull the old chain around the sprockets, taking the new chain with it. Next, figure the length of the new chain and grind off another roller pin to disconnect any excess links. Once done, use a rivet link to attach the ends of the new chain, and voilà! You're done.
Chain in place, a wider range of sprockets can now be used.
November 27, 2011
The Missing Link?
After spending several weekends trying to sort out the ZX10's understeer on corner-exit throttle I concluded there wasn't much I'd be able to do with the current setup to solve the problem. Having looked at several pro-level ZX10 race bikes up close I observed that teams using the stock swingarm were changing the rear suspension linkage to allow better operation of the shock while requiring less spring. One such company doing this was MSS Colchester Kawasaki in Great Britain. After e-mailing MSS Kawasaki, I was pleased to find their linkage setup was available for purchase. Here we have a comparison of the stock tie rod and rocker arm (on the left) to the MSS parts.
Here you can see the extreme differences between the pieces.
To install the tie rods and rocker arm, remove the rear wheel and shock absorber assembly, then remove the stock linkage components and replace with the new parts torquing the nuts to 25 ft lbs.
Here are the MSS parts after install; the rear of the bike certainly feels like it sits a little higher, and there's a perceptible feel of stiffness to the setup, however the true level of improvement won't be known until the next track outing.
December 7, 2011
Never enough power...
Santa came early this year, dropping off a set of oh-so-nice Kawasaki race kit camshafts and adjustable cam sprockets. Word around the campfire is these would go great with some porting and decking, so stay tuned for some serious, eh....tuning : )
CLICK HERE FOR PART 2 OF THE ZX10R BUILD