speed wobbles!!!

[65fury]

Hey guys im new to the motorcycle world and after replacing all my bearings and seals and crap im getting speed wobbles at around 105mph under hard acceleration :damn angry: not cool and very scary. What causes speed wobble? I have brand new metzlers front and rear, had the Yamaha shop balance BOTH wheels, also rebuilt my forks and put on new brakes(busa calipers, glafer rotors)

Thanks

Jason

 

[maleko89]

Check/adjust your steering bearings. Remove front wheel and forks and feel for any notchiness. Lower the stem and check the outer races for wear marks. Do the bounce test and tighten the ring nuts until it's good.

 

[65fury]

Check/adjust your steering bearings. Remove front wheel and forks and feel for any notchiness. Lower the stem and check the outer races for wear marks. Do the bounce test and tighten the ring nuts until it's good.

Ive done bounce test(watched Seans video of it) and i did exactly what he did:biglaugh: the bearings are brand new so i hope they didnt go bad yet!:rofl_200: before i pulled the bike apart i did 120mph and didnt have the slightest wobble, and when i did the bounce test(before installing any new bearings) it was really loose! plus the tires i had were just regular old dunlops that liked to follow every groove in the road, i just cant figure why after doing all new bearings im getting a wobble, would the new tires do that? thanks


Jason

 

[maleko89]

What air pressures are you running in tires?

 

[dannymax]

Are the Metz tires spec'd to oem, or larger? I would tend to look to the tires as the wobble source, that's the only area of major change.

Edit: Does the wobble happen only under hard accelleration?

 

[65fury]

What air pressures are you running in tires?

-35psi front and rear
-im running a 120/90 18 in the front and a 170/80 15 in the rear

but i just found another problem... my rear rim is covered in gear oil!!!! its coming out where the rim and geardrive meet(where those plastice round pieces touch) why would i be leaking gear oil all the sudden?? Ive put 200+ miles on it since i put it back together and never had a leak and now im getting gear oil spattered on my rim:bang head:


Jason

 

[65fury]

Are the Metz tires spec'd to oem, or larger? I would tend to look to the tires as the wobble source, that's the only area of major change.

Edit: Does the wobble happen only under hard accelleration?

Yes for the most part when im WOT and hit 100mph it starts to wobble a lil and gets worse the faster i go , so i slow down:rofl_200:

 

[dannymax]

Yes for the most part when im WOT and hit 100mph it starts to wobble a lil and gets worse the faster i go , so i slow down:rofl_200:

LOL! Good idea! unk:

Will it wobble only at WOT or anytime you get up to those speeds?

 

[rebar]

Yes for the most part when im WOT and hit 100mph it starts to wobble a lil and gets worse the faster i go , so i slow down:rofl_200:

Dont know how you guys live with that shit. Both my 85's have always been rock solid up til 140. My badly cupped avon wobbles when riding slow. One day I might push 5th gear til the light tells the monkey to stop.

 

[65fury]

LOL! Good idea! unk:

Will it wobble only at WOT or anytime you get up to those speeds?

Not sure yet, im still chasing a tuning issue with the carbs so i havent really gotten up to 105mph by moderate acceleration do to some mid range stumbling. All i know is it never wobbled before and ive done 120mph WOT before i changed tires and got all new bearings and such... i dont really need to do 120mph+... but its a VMAX!!! and IT needs to!!:rofl_200:

Jason

 

[mivmx]

Sounds like the rear wheel may be loose. Play will cause the wobble and the leak. Good luck.

 

[65fury]

Sounds like the rear wheel may be loose. Play will cause the wobble and the leak. Good luck.

I hope not!!! :ummm: well actually funny thing is the leak stopped... maybe i just over filled it:bang head: i rode around all day and no leak!

Jason

 

[m-cman]

Don't think you can overfill the rear end. Isn't the fill point to the top of the fill hole?

 

[65fury]

Don't think you can overfill the rear end. Isn't the fill point to the top of the fill hole?

something like that... altho ive heard bottom of the threads is fill point:confused2: i think i got carried away and pumped a bit to much in:ummm: no more leaking now...... so maybe it fixed itsself :rofl_200:

Jason

 

[woodsman30]

something like that... altho ive heard bottom of the threads is fill point:confused2: i think i got carried away and pumped a bit to much in:ummm: no more leaking now...... so maybe it fixed itsself :rofl_200:

Jason

Well not sure about the overfill causing a leak did you check fluid level again? As for your wobble thats an issue in itself. I would look at the tires very close check for and deformations and may want to check tire balance again :confused2:
I would check your front brakes too maybe a little drag in them.

 

[65fury]

Well not sure about the overfill causing a leak did you check fluid level again? As for your wobble thats an issue in itself. I would look at the tires very close check for and deformations and may want to check tire balance again :confused2:
I would check your front brakes too maybe a little drag in them.

havent checked fluid level... but i will, ill also go over the front tire and look for any imperfections, i really dont like this wobble, it limits me to only 100mph:rofl_200: unfortunatly yamaha did the mount and balance and they dont open till tuesday and i might not be able to make it in before i leave. front brakes are good, they had drag in the beggining but not anymore.


Jason

 

[dannymax]

Just shooting in the dark here....did you put it on the center stand, look for runout? Run it up to 5K or so in 5th, see how the rear end acts?

 

[65fury]

Just shooting in the dark here....did you put it on the center stand, look for runout? Run it up to 5K or so in 5th, see how the rear end acts?

Havnt tried that.... and im missing the center stand with the 4-2-1 kerker, sooo not sure how to go about that:confused2:

Jason

 

[woodsman30]

havent checked fluid level... but i will, ill also go over the front tire and look for any imperfections, i really dont like this wobble, it limits me to only 100mph:rofl_200: unfortunatly yamaha did the mount and balance and they dont open till tuesday and i might not be able to make it in before i leave. front brakes are good, they had drag in the beggining but not anymore.


Jason

I would recheck those calipers you installed if you can put the bike up in the air and spin your tire while working your brakes just to see what happens. Even just a little drag from either side of the front brakes could give you a problem. Defiantly start with the basics here you did not have a wobble before so do check on everything you done are far as a replacement.
Keep us posted to what you find and if this gets fixed it help all when we know what the problem was for future reference that others may have the same issue unk:
Good luck

 

[65fury]

I would recheck those calipers you installed if you can put the bike up in the air and spin your tire while working your brakes just to see what happens. Even just a little drag from either side of the front brakes could give you a problem. Defiantly start with the basics here you did not have a wobble before so do check on everything you done are far as a replacement.
Keep us posted to what you find and if this gets fixed it help all when we know what the problem was for future reference that others may have the same issue unk:
Good luck

Good idea, ill do that today, and ill definanlty post back on any findings with my speed wobble and even my tuning problem. Thanks


Jason