RVF Front end vibration

[jamesbutler]

Hi I have a small problem with my NC35 I have just changed my front wheel bearings and fitted gilles clip-ons on the bike. I took it for a quick test ride today and found under braking i get a violent vibration or shaking on the front end. It only occurs arround 90-100kmh if i brake hard at 180 i dont get it. I suspect maybe a warped disc ?
any ideas ?

PS. it wasn't doing it before i changed the wheel bearings and clip-ons.

[montsta56]

Silly Question Maybe but have you got the spacers roundthe right way???

[jamesbutler]

No i don't think so ive taken the wheel of a few times before and if i remember correctly the bigger spacer goes on the left when facing the bike. And the vibration is only under braking and i think if i had inverted the wheel spacers the discs wouldn't fit in the calipers.

[skinnydog0_0]

Yes it may well be warped discs, but i had a warped disc and i could feel that at all speeds. I would say it got worse the faster i went.
Have you checked the steering head bearings arn't loose, that could feel like a bit like a warped disc.

[G-MAN]

Suppose they are bent then did you do the job on the ground and used your knees on it trying to keep it balanced so that you can hammer away at it. because every bang would put pressure on the disc and this is probably why its there now and not before.

[Cammo]

How did you do the front wheel/axle up??

Make sure you tighten the axle bolt (the big one!) before tightening the axle clamp bolts (4 x 12mm) so that the axle sits true and proper - unloosen them all and do this properly.

The small spacer goes on the left hand side (when sitting on the bike), sounds like you have them the right way - and yes the discs probably won't fit if you cock this up.

I doubt your discs are warped it it has only just happened!!

[jamesbutler]

when remounting the wheel i put the spacers in the same way they came off put the calipers back on then put the axle through then tightened the axle bolt then tightened the 4 screws in the forks tightened the caliper bolts remounted mudguard. I had the wheel laying on the discs when i took the dust seals out then put the wheel on two blocks of wood supporting the rim not the disc when it came to bashing out the old bearings and adding the new ones.

But you said the big spacer is on the left when sitting on the bike mine is on the left when facing the front end of the bike but i do have SP1 calipers on the bike maybe thats why...

[Old Painless]

What happens when you raise the wheel off the ground and spin it by hand ?

[jamesbutler]

When i spin the wheel of the ground i runs sweet and straight a bit of rubbing from the brake pads but thats normal.
i think it might be a slightly bend disc because i rode the bike today and i had a lot of vibration under braking when i first got out but after 1 hour of riding i was doing it a lot less.

so i think it must have sorted its self out but thank you all for your input very appreciated..

[skinnydog0_0]

Did you check for play in the headstock bearings?