So you fancy going racing? Well, here’s a sobering thought; club racing, like crack cocaine, is highly addictive, leaves you bankrupt in 3 months and wrecks you physically and mentally. But you might feel good for a few minutes at the weekend…
To keep things vaguely sensible, choose a bike like the CBR600F to race. It´s fast, durable and you can always sell it on to another hopeless addict, once you´ve utterly thrashed the hell out of it – bonus!
Chris Pearson offers some useful CBR600 track tips.
The CBR600 is, and always has been, a damn fine road machine and none better than the latest version; the FS.
We started off with a brand new model, made lighter for the track by removing the lights and fitting race bodywork. The engine is completely standard at present except for a race can, although we do have the ability to alter the fuel mapping if required. Already fitted with mega sticky race rubber, in the form of Metzeler Rennsports, all that was left before entering a race proper was to sort out the handling. The bike was taken to Cadwell Park to be run in and pretty soon, the pitfalls of running a road machine on a pukka circuit became apparent.
Initially the suspension, being still on the standard settings, proved more than a little supple with big wallows on the drop down through Chris curve and around Charlie´s. Of course this behaviour is acceptable on the road as the surface goes up and down like a whores knickers, but on a relatively smooth race circuit you need to be able to get the hammer down and that means a stiffer set up.
Ten laps were completed and the best time we had achieved around the one and a half mile club circuit was 1 min 8 secs dead. This was with a completely stock machine apart from the tyres.
Back in the pits, and the preload in the front forks was wound in two and a half lines, leaving just one and a half still showing. The rebound damping was the stiffened up by half a turn and likewise the compression damping, located at the bottom of the fork slider.
This made the front end dive considerably less under braking and consequently made the machine more stable off the brakes and through mid corner. The CBR600´s rear end is just as adjustable and we settled for spring setting number five and the compression-damping wound in half a turn. With the rebound also turned three quarters in the bike now felt firmer with hardly any noticeable squat when the power was applied. This gave more ground clearance and shaved seconds off the previous lap times.
The tyre pressures were dropped from the manufacturers recommendations to a more forgiving 30psi front and 32psi rear, this immediately gave more feel especially mid corner and under acceleration.
Times were now down to the 1 min 5 sec mark so we were starting to get some positive results from our work.
The engine was revvy and willing to keep on revving, eventually bouncing off the limiter around about the fifteen mark, giving us nearly 135mph down the back straight. It wasn´t quite pulling top gear, so it was back in the pits to change the rear sprocket. Up two teeth and the bike zipped along all the more willing with a tad under 140 showing on the speedo before having to brake for the sharp right at the end of the straight.
The larger sprocket created considerably more squat under acceleration due to the extra leverage now happening on the top side of the swingarm, so we needed to come up with a combination of front and rear sprockets to minimize this undesirable effect.
The rear was given more spring (one notch harder) and compression damping (half a turn in) to stop the squat, which it did, but if anything it served to make the bike too firm at other times, so the gear ratio definitely needs altering to combat this. We were fast running out of adjustment at the rear end and eventually a more upmarket (read mega bucks) shock will be necessary.
Also noticeable after the gearing change was the bike´s keenness to depart from any chosen line. This was due to the rear wheel moving forward to create the slack in the chain, this having shortened the wheelbase by nearly an inch making it turn very quick indeed. By now my fastest lap was some 1min 4sec so we had started to shave serious amounts of time off our initial lap time around the club circuit and the bike was feeling better and more controlled all of the time.
The fuel injection was faultless on the track, just as it is on the road, making the FS very agile and easy to accelerate hard out of corners, particularly out of Park corner and the Gooseneck, where a reluctance to wind back the twist grip early always creeps in. The induction roar, from the ram air two tubes, just below your forearms, exaggerates the going forward bit tenfold, it really is a superb sound.
No improvements were deemed necessary in the braking department. Using standard Honda pads the brakes are nothing short of awesome, even with a run of intense race pace, laps the brakes never faded or felt inadequate. We did try some aftermarket pads but if anything, they did not work as well as the standard fitment. The lever adjustment was backed right off to the softest setting to produce simply stunning two-finger braking even into the very hardest sections of Cadwell like the Hairpin and Mansfield.
At no time did the CBR600FS shake its head, so at present, and somewhat unusually for a road going machine, it looks like a steering damper will not be required for the track. Already we had knocked off a full one second per lap than the fully tuned CBR we ran last year – and that was with a standard FS engine!
A few weeks later the CBR was taken to Donington, in the hope of pushing her a wee bit further. Much work had been done in the meantime on the dyno concerning fuel/ignition mapping and gaining a few extra gee gees, so I was keen to see if it worked.
The rev limiter had been disabled allowing considerable over-rev (handy at Donington) and now she was happy to nudge the sixteen thou mark if required. The handling set up that we had arrived at for Cadwell was perfect, even for the smoother national circuit. So much so in fact, that the rear could be hardened slightly without ill effect.
This helped with the gearing problem causing too much squat although we have now gone down one tooth on the front and back to the standard rear sprocket, to maintain a very similar ratio to the one tried at Cadwell.
The big test on this circuit is always Craner Curves, if you have any problems at the front end it will show its ugly face down there. Luckily the CBR took it all in its stride.
Get Honda motorbike insurance for the honda cbr600fs.
Engine……….liquid cooled, DOHC, four cylinder, four stroke, cc 599
Cycle parts……….Steel perimeter type frame
Forks………. 43mm multi adjustable
Rear suspension……….Stock Honda Monoshock, multi adjustable
Brakes……….Twin disc, stock callipers and pads
Top speed……….Variable, depending on gear ratios
Fuel capacity……….17 litres
Current price……….Depends on team budget!