On my 96 vfr750 i tried doing some hard braking on some nice fairly new, flat asphalt, during witch the front will start to headshake real bad right before the front tire breaks traction giveing me a REALLY uneasy feeling, im guessing maybe my steering head bearings and/or front wheel bearings need replacement. just a side note, it will also start to headshake fairly bad when im in 2nd or so gear and up at 10k and let go of the throttle and let go of the handle bars. i have to kind of make it headshake that way, but its fairly easy. any hints/tips/tricks to prevent this, espically under braking.
how high do you have the rear or how high have you raised the forks? i had an RM 250 that was like that (steve crowe's bike hurricane!) that thing would head shake a storm on me. other that those conditions i'd check like hurricane249 has stated ....maybe wheel bearings too, but they most likely always be noticeable
767fixer, Jan 21 2005, 05:15 PMhow high do you have the rear or how high have you raised the forks? i had an RM 250 that was like that (steve crowe's bike hurricane!) that thing would head shake a storm on me. other that those conditions i'd check like hurricane249 has stated ....maybe wheel bearings too, but they most likely always be noticeable
Wheel bearings generally don't shake on acceleration or braking only when maintaining a constant speed, guess it has something to do with force exerted. At least that has been my experience.
I think the shake in the RM250 was from rider fear and not the forks too high in the triple clamp. :lol: (insert taunting emitcon here)
Hurricane249, Jan 21 2005, 06:19 PMWheel bearings generally don't shake on acceleration or braking only when maintaining a constant speed, guess it has something to do with force exerted. At least that has been my experience.
I think the shake in the RM250 was from rider fear and not the forks too high in the triple clamp. :lol: (insert taunting emitcon here)
a 96 must have a lot of miles, yea I am thining the steering head bearings are shot too. Chapperal has all balls taperd bearing sets for the 96vfr for around 35$ just do a google for them. Installing them is not rocket science just takes time and is a bit labor intesive.
I agree with the steering bearings also but check your front tire for cupping. My 4th gen cupped everybrand and every tire I put on it. It would also do the things you talked about as far as hard braking and letting go of the bars and the head would start to shake. How to fix it? I never could get it right. I put tapper bearings in my 96 and then switched to Michelin Pilots and that setup helped but eventually they also cupped just not as bad as before. I soon sold my 96 and bought a 98 and the 98 still cupped tires too but not near the extent of the 4th gen head shake.
Sounds like a combo steering head bearing and tire problem. On my 94, I raised the piss out of my fox shock and lowered the front forks, and never had an ounce of head shake. I don't think that is your problem. I found that a significant contributer to cupping the front tire is due to letting off the gas in fast corners, and/or springs that are too light for a heavier rider. JM2C
ULEWZ, Jan 22 2005, 11:55 AMSounds like a combo steering head bearing and tire problem. On my 94, I raised the piss out of my fox shock and lowered the front forks, and never had an ounce of head shake.
the ducati used to head shake like crazy with the rear hiked up....but after i thought about it for a while it was under accelleration that it did it , <_< damn st's dont come with dampeners (insert shaking head emoticon here) ..... ignore my initial post about braking steering rake head shake (insert fixer has alzheimers emoticon here)
just to think of it fellas, i really appreciate all the feedback, and hope for a little more, and the more i think about it, i guess the front dosnt 'headshake' persay, but more or less a 'fork hammering' like the front tire is bounceing under braking. just to note also, i just had the front forks rebuilt, revalved, and resprung by professionals. although i never got hard on the brakes with the old blown forks, i doubt its the actual build of the forks.
Bejbis, Jan 22 2005, 07:39 PMjust to think of it fellas, i really appreciate all the feedback, and hope for a little more, and the more i think about it, i guess the front dosnt 'headshake'� persay, but more or less a 'fork hammering' like the front tire is bounceing under braking. just to note also, i just had the front forks rebuilt, revalved, and resprung by professionals. although i never got hard on the brakes with the old blown forks, i doubt its the actual build of the forks.
Big difference between fork hammering and headshake. Now I change my online diagnosis to warped brake rotors, or glazed brake pads. I would take the pads off, ruff them up with sandpaper, and reinstall. I also stand by my diagnosis of tire cupping causing this problem. What kind of tires (brand, model, miles since new) are you using? Let us know what you find. ;)
Put the bike on the centerstand and put a jack under the headers so you can lift the front wheel off the ground.
This can reveal 2 things. spin the wheel and see if its rubbing at all when the wheel reaches a certain point, indicating a warped rotor. second turn the bars side to side and feel for notchy feeling, indicating worn steering bearings. Then back to the wheel see if you can feel any looseness in the steering column by gently pushing on the wheel front and back. dont go crazy and knock the bike off the jack.
If your steering bearings are shot you will feel a charactoristic "Clunk" when you brake especially when you come to a stop. that clunk is too much play between the bearings and the races from wear so they crash into each other when a stopping force is applied.
The stock bearings are ball bearings and they make point contact where the balls touch the race. Tapered bearing use pins rather than balls so the entire race contacts the entire pin length spreading the load over a larger surface rather than a ball point. Mine were shot after 35k cause I ride hard and sometimes over dirt bumpy roads. Replaced them with the better tapered ones should last much longer.
cool, thanks slammer, ill get to that after work on this incredibley cold sunday. it was 70 degrees this time yesterday, now its 29!
anyways, tires are bt014 on the front, and bt020 on the rear, both have ~5k miles on them of fairly hard rideing and have probally 2k left on them. bike has a total of 25k miles, i think its probally time to just replace all the bearings up front, and just make a day out of it.
Bejbis, Jan 23 2005, 09:42 AManyways, tires are bt014 on the front, and bt020 on the rear, both have ~5k miles on them of fairly hard rideing and have probally 2k left on them.
7,000 miles from the tires when doing spirited riding? I should be so lucky.
well....as spirited as you can ride in lower alabama, i grind pegs on a regular basis, but then again, i do alot of slabbing too, they will be dead because of the slabbing more than the turns end the end though. needless to say, i go out of my way to include the higher speed curves i like into my ride.
Bejbis, Jan 21 2005, 02:25 PM any hints/tips/tricks to prevent this, espically under braking.
-Daniel
Sometimes when the precision rolled bearings that are teflon lined wear thin and the play between the inner and outer fork tubes grows... there comes a point when the wheel to allowed to flop about under load...
The items I'm referring to are #9 and #10 in this drawing... Ron Ayers Parts Link
Please note that most bikes will experience a normal deceleration wobble if you let go of the bars... most noticeable as speed drops in the 40 to 30 range... grip the bars back and it should go away...
Bike manufacture spend huge sums of money working directly with tire manufactures in designing special tires specifically for each model that quills this natural tendency the most...
End of thread · 19 posts recoveredWayback Machine snapshot 3 May 2005