I have a track bike that seems to have a very fine vibration, changed chain and tightened the headstock bearing but still really bad? It get seriously bad when going through the twisties in 3rd-4th gear at 12k-16k rpm Any help appreciated.
any idea where the vibration is coming from? do you feel it in your hands, tank, feet, etc. are you sure the rear wheel is aligned properly if you changed the chain? checked the steering head bearings?
It's a high frequency vibration that I think is speed dependant, I'll try the headstock bearing and see if that makes a difference, the vibration can be felt all the way up my ass and through my inner thighs. An even bigger issue that came apparent at jerez was the inability to hold a constant throttle or get on the gas easy when coming out of the corner without it stuttering and feeling like it was cutting out, only seemed to happen when hot and never when WOT
Random ideas: - bent wheel - out of balance or out of round tire - bad wheel bearings - out of round or bent sprocket - loose chassis bolts like subframe, engine, etc Based on super limited info here, I think the last is most likely. The rest are ez to rule out either way.
If you feel it in the seat, then it's really likely not headstock bearings. I had a broken clutch basket that I swore was an out of balance wheel because the vibration was only apparent at speed. However, it turned out that the vibration was worse at high RPM/high load, which is experienced going down the straightaway. Another consideration is your fuel maps or something in the injectors/EFI system. A misfiring cylinder (plugged injector or bad spark plug) can cause high frequency (or even low frequency) vibrations, and a misfire can also cause poor low throttle opening issues. I suggest a trip to your local dyno operator for a full load/high RPM analysis.