Brian's ZXR750R Racer
This bike sports more Racekit/Factory parts than most factory bikes and Brian has paid enormous attention to lightening up every component giving some very impressive results!!!
Here's the list of his mods and the bike's spec
Engine
- Current motor : ex-All Japan Superbike, full 'optional' kit spec, dynoed at 142hp with cams timed for midrange (since re-timed for top-end), various factory magnesium covers and cable clutch conversion
- Previous motors :
- Original L3 engine, full kit spec
- Ex- Team Kawasaki Australia '94, built around WSB internals from the previous year. Nothing particularly special ('optional' kit spec), other than the factory crank
- Next motor : ex-Team Kawasaki Australia '95, semi-factory spec (factory cams and gear-driven oil pump, titanium valves, otherwise full 'optional' kit spec). Original engine builder suggested it was good for a.150hp. Rebuild will include titanium conrods and seriously lightened crank (minus 2.5kg) and clutch assembly (minus 0.8kg)
- OEM FCR 39 carbs, with 'optional' kit parts added
- Carbon-fibre airbox enclosing carbs
- Fabricated breather box for crankcase
- Kit magnesium throttle assembly
- 96+ kit titanium pipe (ex-Craggill)
- 96+ kit ignition, with earlier CDI
- OEM L radiator (kit radiators available for very hot days), lowered to fit airbox, and thermostat assembly removed
Chassis
- Lightened & braced M frame
- Ride-height adjuster threaded into frame
- Lightened & braced subframe
Replica '96+ kit rearsets
- ZX6R aluminium gearshift knuckle
- ZX9R aluminium gearshift linkage rod
- Early factory braced K swingarm (ex-Bayliss)
- ZX7R aluminium swingarm pivot sleeve
- Titanium swingarm pivot
- Titanium engine mount bolts
- Regina 520 chain, Renthal / AFAM / kit sprockets
- Fabricated aluminium fuel pump mounting bracket
Suspension & Steering
- '92 Ohlins 42mm chrome forks (ex-Mladin)
- Factory magnesium triple clamps, 30.5mm offset
- Woodcraft clip-ons
- '96+ Ohlins piggyback shock with billet body (ex-Muzzy)
- RCS titanium 9.5kg shock spring
- Kit OH3 linkage
- Aluminium dogbones
- Titanium and hollow steel (R1) linkage through-bolts
- Marvic Penta front wheel
- Marchesini 5-spoke rear wheel
- Ohlins steering damper
Brakes
- AP 6-piston calipers
- PFM narrow-track cast-iron discs
- Goodridge kevlar front brake lines
- Brembo 19x20 radial master cylinder, using OEM clutch master cylinder reservoir
- Kit rear caliper and mounting bracket
- Kit rear disc
- Goodridge braided rear brake line
- Goodridge aluminium banjo bolts on calipers
- Goodridge bleeder aluminium banjo bolts on master cylinders
- Fabricated aluminium torque arm for rear caliper
Bodywork
- Carbon-fibre front guard
- Carbon-kevlar factory fairing (ex-Bayliss)
- Aluminium fairing mounts
- Kevlar-fibreglass tank
- Carbon-fibre tailpiece
- Carbon-fibre ram-air intake
- Carbon-fibre battery box
- Carbon-fibre tank mounting bracket
- Lightweight double-bubble screen
Ancillaries
- Kit wiring loom (total-loss)
- Yuasa YTX4LBS battery
- Daytona coolant temperature gauge
- Daytona shift light
- More aluminium and titanium fasteners than you can shake a stick at !
Last weighed at 154 kg half-dry, with over 3.5 kg removed since then.
Future Plans (when time and/or money allow)
I firmly believe that a half-dry weight of under 140 kg is achievable with a very fat wallet, but realistically I'm aiming for under 144kg. I'm also hoping for close to 160hp, to give a power to weight ratio of around 1.1. Being something of a purist I'd prefer to keep the bike a 750 and see just how far I can take it, but, realistically, when my stock of parts for kitted engines runs out, it'll be time to look at a bigger engine.
My present thoughts are along the lines of a worked ZX12 engine (which will no doubt involve extensive chassis modifications).
All that torque and power in a short wheelbase would be most entertaining :)
In the meantime, I have a number of small projects to be work on :
- Installation of an electric water pump
- Crankcase breathing mod
- Fit carbon-fibre handlebars
- Titanium axles
- Lighten shift drum
- Refurbish and fit magnesium cush drive
- Rebuild and install later more heavily-braced swingarm
- Research plugmount coil sticks
- Research aluminium cylinder sleeves (liners)
- Fabricate high-capacity crankcase breather
- Fabricate magnesium engine and wheel spacers, and engine mounts
- Fabricate aluminium or titanium radiator mounts
- Fabricate aluminium rear disc
- Fit BST carbon-fibre wheels, BrakeTech ceramic discs and a Suter dry clutch when I win the lottery !