Race set-up VFR800 V-tec

Hi Guys, does anyone ride trackdays with his VFR V-tec (no ABS)2002. I have a Ohlins springcartridge upgrade but have not yet changed the rear shock absorber. When I brake hard from 200 kpH to 50kpH my steer starts vibrating vertically real hard.I also have a steering damper mounted and a Brembo RCS19 radial master brake cilinder with brembo race pads. My discs seems alright and my steer bearings are recently changed by new. Has anyone got wave discs mounted? I loose so much time braking at the end of a straight high speed section.

Greetz
TomVFR23

 

your best best is a fork and spring set for your weight and 15wt oil in the forks... braking HH EBC pads

 

Can you tell us a bit more information like tire make and model as well as pressure that you are running. Track condition could also be a factor. Have you experienced this at other tracks and or is it doing the same thing into every corner? Is the front tire chattering and chirping at the limit of traction?

I ask this because I noticed similar issues when braking at or near the limit but only on certain corners of specific tracks where the surface was rippled from the cars heavy braking.

 

Rode on track in France with 2 bar in font tyre and 2,2 in rear tyre. Bridgestone battlax BT016 and another try with BT-003 RS Conditions were 25°C sunny weather. I have not the idea that my front tyre is at the end of traction. The shatter sets in when pull on the pressure to increase my deceleration.
It also happens when i'm street racing and have to stop at street lights or sharp corners. Could it be that my front fork is out of angle by pulling power wheelies?

 

Tire pressures are about where I would be running. It really sounds like a brake disc or pad combination issue which could be compounded by old or incorrect fork oil. Check the discs for runout to see if one of teh rotors are warped. I don't think the wheelies will cause the front end to get twisted at least they never did for me but perhaps you do them bigger and better!

 

Yeah, maybe the disc/pad combination doesn't work optimal. Do you still have the original discs? What would you think about wave-discs and new pads. Do you have the combined braking system eliminated or does it still functions as standard?

 

Have you got any performance details of your 2002 V-tec. Have you tested him on a dynojet test bank?
Seems like you have almost the same exhaust and Power Commander.
My bike has 107,6 bHP and 85Nm torque at the rear wheel.

Greetz

 

I'm running stock discs and I have run stock pads for track days with good results. EBC pads work well with a much stronger initial bite.

I haven't dyno'd this VFR as it is mostly a road mount and my ass dyno tells me all I need to know. It does look like our setups are similar but my exhaust is not a VALE system, it is called "The Stash" because the LH can is actually a storage compartment and the engine breathes through the RH side only.

 

Oh it's the same with the VALE system. Only the RH can respires the engine. The LH can is just extra weight.
I try to post a pic but i don't succeed. I'll try on...

 

One quick thought is to check your steering stem bearings, that can also cause a "chattering" in the front brakes.

John

 

Thanks, but I already replaed the bearings by "conic" types that wouldn't wear out as fast as the originals

 

just a photo of the aftermarket exhaust by Two Brothers