High speed wobble

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The FF is definitely controversial.

I know I've "fixed" things just buy taking it apart, looking at it, scratching my head, then putting it back together. I can't explain it but it's true. Just happened last week.

I had a pull rope starter that wouldn't retract. I removed it from the engine. Cleaned it and the problem remained. Loosed on bolt and it worked. Tightened said bolt and it still worked. Made no sense but I wasn't too worried about it.

Kinda like how the FF has helped some guys. I have no idea how replacing the rubber washer with a metal one would make a damn difference. The bottom nut sets bearing preload so, theoretically, once it's set I'd think you could throw the rest away and it should be fine. If it works, it works.

I got away with adjusting them myself. Mine was a low speed wobble. Say 50 mph or so.

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[Traumahawk]

Eric the main reason you get rid of the rubber washer is because the bearings are suppose to get tighten to 10 inch pounds. :ummm: At that point you got the bearings so over tightened there acting like a steering damper. I agree 100% with what you said do everything the right way & there shouldn't be any problems.

Dave

Thanks.

Years ago I bought one of the best tools. It is the steering head (spanner) wrench. Dingy makes them, and it makes it very easy.

Edit** Here is the wrench. http://www.ebay.com/itm/Yamaha-Stee...m280c625726:m:m_P5MsNoHf17_VAMA31Bpnw&vxp=mtr

When I first bought the bike, I had a wobble at 35 and then again at 70. Made for an interesting ride home. I wasnt on the forum, didnt know about the Vmax "wobble", and also the front forks had 0 lbs of air in them, and I bought this bike from a Yamaha dealer, and they should know all of these things.

 

[Miles Long]

Miles
I'm hoping that you can help me out, because I'm kind of skeptical of the Furbur fix, and let me say why. Not everyone when they work on a bike will apply some sort of scientific methodology to the bike during the fix.

So, your basically replacing the rubber washer inbetween the 2 castellated nuts on the steering head, with a flat metal washer, and then you tighten everything up, and take off and problem solved. I wonder how many how many people had loose steering head bearings (causing the actual wobble), put in the flat washer, tightened everything up (so tightened up the steering head bearings) and then called it fixed....when it wasnt the washer that fixed it.....it was doing the proper thing and tightening up the steering head bearings that worked.

You do a great job on your bike, and I was hoping that you had some insight to this?

Thanks

Eric, too many posts to link, but this one will outline my thoughts about why the F.F. works. The thread also contains Jim's take on Blinker fluid as the source of headshake. And he thinks I'm nuts!:biglaugh:

http://www.vmaxforum.net/showthread.php?t=28384&highlight=furbur

If you want my other entries, do an advanced search, keywords furbur fix, with Miles Long as the originator.
In a nutshell - I followed John Fubur's instructions, only replacing the Al. washer with a stainless one.
- the bike had a low speed (30-50 kph) wobble since purchasing it new in 03
- The dealer checked and adjusted the headstock bearings once, I did it twice, wobble remained. Progressive springs and a wrap-around fork brace did nothing for the wobble. Following a low-speed "tank-slapper", I then did the fix, in June of 010
- The bearings have never been replaced , just inspected and lubed twice. Small adjustments have been made with the two nuts because of bearing wear. I have the complete assembly matchmarked, to make sure nothing loosens up.
- The bike is now at about 64K miles. The low-speed wobble has never returned.
The bottom line is that it worked for me!
Cheers, take care (and I mean you as well, Jim!)

 

[Traumahawk]

Eric, too many posts to link, but this one will outline my thoughts about why the F.F. works. The thread also contains Jim's take on Blinker fluid as the source of headshake. And he thinks I'm nuts!:biglaugh:

http://www.vmaxforum.net/showthread.php?t=28384&highlight=furbur

If you want my other entries, do an advanced search, keywords furbur fix, with Miles Long as the originator.
In a nutshell - I followed John Fubur's instructions, only replacing the Al. washer with a stainless one.
- the bike had a low speed (30-50 kph) wobble since purchasing it new in 03
- The dealer checked and adjusted the headstock bearings once, I did it twice, wobble remained. Progressive springs and a wrap-around fork brace did nothing for the wobble. Following a low-speed "tank-slapper", I then did the fix, in June of 010
- The bearings have never been replaced , just inspected and lubed twice. Small adjustments have been made with the two nuts because of bearing wear. I have the complete assembly matchmarked, to make sure nothing loosens up.
- The bike is now at about 64K miles. The low-speed wobble has never returned.
The bottom line is that it worked for me!
Cheers, take care (and I mean you as well, Jim!)

Thanks for that answer Miles. I will check up on that. Thank you. Have you ever thought about taking a trip down South? Jim and Shayla are a LOT of fun in person.

 

[Zeus36]

Great tech article, but NOT in favor of the Furbur Fix:

http://vmax.lvlhead.com/tips/vmaxshakes.htm

 

[gleno]

Why are you trying to define a front end handling problem when your tyre pressures are not stable :ummm:

Fix the leak. Run correct pressure.

Then look for the problem (which will probably have gone).

Correct tyre pressure is fundamental to correct handling unk:

 

[Lotsokids]

Why are you trying to define a front end handling problem when your tyre pressures are not stable :ummm:

Fix the leak. Run correct pressure.

Then look for the problem (which will probably have gone).

Correct tyre pressure is fundamental to correct handling unk:

I slightly disagree, but yes, tire pressure should be stable. My point about the tire pressure is that the bike develops the wobble at 20 PSI AND at 40 PSI. But sometimes no wobble at 20 or 40. So tire pressure is not the root cause.

 

[dannymax]

I doubt there is any single cause for speed wobbles, or any single fix.....what works on one bike may or may not work on the next one. It appears that wobbles are common to motorcycles in general, you will find a wobble post mentioned on nearly every bike forum on the internet.

Hell, even the GP bikes wobble, and they get the very best of everything!

 

[Dorney]

The FF is definitely controversial.

I know I've "fixed" things just buy taking it apart, looking at it, scratching my head, then putting it back together. I can't explain it but it's true. Just happened last week.

I had a pull rope starter that wouldn't retract. I removed it from the engine. Cleaned it and the problem remained. Loosed on bolt and it worked. Tightened said bolt and it still worked. Made no sense but I wasn't too worried about it.

Kinda like how the FF has helped some guys. I have no idea how replacing the rubber washer with a metal one would make a damn difference. The bottom nut sets bearing preload so, theoretically, once it's set I'd think you could throw the rest away and it should be fine. If it works, it works.

I got away with adjusting them myself. Mine was a low speed wobble. Say 50 mph or so.

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Mike when you loosened it up & tried it it set the alinement then you tightened it & you were good to go. Over time that can happen from wear just loosen the bolts as you did give it a couple pulls tighten all fixed. :clapping:

Dave

 

[DMAN999]

I did the Furbur Fix procedure years ago, following low-speed wobble issues. No problems since.
In your case - high speed issues, can you narrow down the advent of the wobble to the sequence of the modifications you performed?
If not, I would correct the only obvious variable, to begin with - the air pressure(s) in the front tire. Have the leak fixed, and inflate to standard pressure.
If that doesn't work, I'd next look at the new brace. Perhaps the added stiffness has changed the natural frequency of your front end enough, so that certain rotational speeds of the tire are causing a resonant condition. Try using the original brace, at the same speeds and on the same roads that caused you grief.
It's all about the process of elimination.
JFeagins will no doubt chime in soon, re that new back tire. Apparently any wobbling issues that he has had have originated with rear tire alignment issues.
Cheers!

:rofl_200: unk: :rofl_200:
I personally never did the Furbur Fix and have never had any wobble.
I do the Bounce test on my Vmax every Spring and adjust the steering head bearing tightness.
BUT, if I did have a wobble issue I would Not hesitate to try John's fix.

 

[gleno]

I slightly disagree, but yes, tire pressure should be stable. My point about the tire pressure is that the bike develops the wobble at 20 PSI AND at 40 PSI. But sometimes no wobble at 20 or 40. So tire pressure is not the root cause.

Who runs 20psi???!!!!! ... and expects a bike to handle predictably!!!

Please read

http://www.vmaxforum.net/showthread.php?t=3827&highlight=gleno

http://www.vmaxforum.net/showthread.php?t=2605&highlight=gleno

 

[Redbone]

Eric, too many posts to link, but this one will outline my thoughts about why the F.F. works. The thread also contains Jim's take on Blinker fluid as the source of headshake. And he thinks I'm nuts!:biglaugh:

http://www.vmaxforum.net/showthread.php?t=28384&highlight=furbur

If you want my other entries, do an advanced search, keywords furbur fix, with Miles Long as the originator.
In a nutshell - I followed John Fubur's instructions, only replacing the Al. washer with a stainless one.
- the bike had a low speed (30-50 kph) wobble since purchasing it new in 03
- The dealer checked and adjusted the headstock bearings once, I did it twice, wobble remained. Progressive springs and a wrap-around fork brace did nothing for the wobble. Following a low-speed "tank-slapper", I then did the fix, in June of 010
- The bearings have never been replaced , just inspected and lubed twice. Small adjustments have been made with the two nuts because of bearing wear. I have the complete assembly matchmarked, to make sure nothing loosens up.
- The bike is now at about 64K miles. The low-speed wobble has never returned.
The bottom line is that it worked for me!
Cheers, take care (and I mean you as well, Jim!)

Chasing down the wobble issue seem to have many positive fixes. I had an issue with a slight wobble at slow speeds (35-40) and only on right hand corners and while doing the bounce test I also checked forks pinch bolts (front off the ground still) fork brace bolts and axle bolt. Somewhere in that exercise I eliminated my wobble issue, I'm not sure if it was one thing or a combination of things, it pays to look at all the involved pieces for your solution.

I doubt there is any single cause for speed wobbles, or any single fix.....what works on one bike may or may not work on the next one. It appears that wobbles are common to motorcycles in general, you will find a wobble post mentioned on nearly every bike forum on the internet.

Hell, even the GP bikes wobble, and they get the very best of everything!

They do and do it with spectacular results at times. I also think that there is no one fix and the owner would do well to check all variables when fixing a persistent wobble issue.

:rofl_200: unk: :rofl_200:
I personally never did the Furbur Fix and have never had any wobble.
I do the Bounce test on my Vmax every Spring and adjust the steering head bearing tightness.
BUT, if I did have a wobble issue I would Not hesitate to try John's fix.

I have only done the bounce test vs. the FF and also check bearings/ lube every couple of years. Since adding a extended braced swingarm and aluminum motor mounts I have not noticed many issues with handling other than when pushing hard and triple digits the front end seems a little imprecise but that is probably due to having the skinnier front forks. Sean may yet be building me a sport bike USD fork set which I have always admired for their looks but with all the work I've done to my stock forks they have been mostly acceptable for my uses.

 

[dannymax]

I have only done the bounce test vs. the FF and also check bearings/ lube every couple of years. Since adding a extended braced swingarm and aluminum motor mounts I have not noticed many issues with handling other than when pushing hard and triple digits the front end seems a little imprecise but that is probably due to having the skinnier front forks. Sean may yet be building me a sport bike USD fork set which I have always admired for their looks but with all the work I've done to my stock forks they have been mostly acceptable for my uses.

I got great results with my '86 forks with Progressive springs, new sliders, seals, spindle tapers, etc., a thorough cleaning and new oil.....and altho I don't try to follow you Michigan guys...I think she handles like a new one!

 

[Lotsokids]

Who runs 20psi???!!!!! ... and expects a bike to handle predictably!!!

You're missing the point completely.
The pressure check was AFTER a wobble. Then I pressurized to about 40 PSI hoping that was my problem, but it wasn't.

I proved that tire pressure is NOT the root problem.

I do not intentionally run 20 PSI, but as I said, there is a slow leak. I don't check tire pressure every time I ride. It holds for 2 or 3 weeks.
You're kind of "wrapped around the axle" on the pressure issue.


I think my best plan is to replace the bearings. Grease and set it properly. That's about all I have left to do.

 

[blaxmax]

You're missing the point completely.
The pressure check was AFTER a wobble. Then I pressurized to about 40 PSI hoping that was my problem, but it wasn't.

I proved that tire pressure is NOT the root problem.

I do not intentionally run 20 PSI, but as I said, there is a slow leak. I don't check tire pressure every time I ride. It holds for 2 or 3 weeks.
You're kind of "wrapped around the axle" on the pressure issue.


I think my best plan is to replace the bearings. Grease and set it properly. That's about all I have left to do.

" I don't check tire pressure every time I ride."

I do.

 

[Redbone]

I got great results with my '86 forks with Progressive springs, new sliders, seals, spindle tapers, etc., a thorough cleaning and new oil.....and altho I don't try to follow you Michigan guys...I think she handles like a new one!

Yep, I have my stock forks kitted out with Progressives, Ricors, adjustable spring tensioners, and I've replaced most of the internals that showed any wear. Also a Python fork brace and probably the biggest mod was the Carrozzeria wheels, which is probably some of the issue; most every thing for stiffening up the frame, swingarm has been stiffened and with the radials urging me to go faster is why the forks are feeling a bit dated. Or it could be 'ol Zip putting images in my head of black chrome USD forks and triple trees. Yup he has it pretty well thought out, damn Zip!

 

[dannymax]

Yeah....damn Zip....cost us many dollars over the years eh, BB? :bang head:

Evil little primate!! :th_smilie:

 

[Lotsokids]

" I don't check tire pressure every time I ride."

I do.

I think we have different definitions of "ride." :confused2:
I have 4 -6 riding events each day. That's a lot of pressure checks each time.

 

[Specs95t]

Yesterday, I took Zveruga out for a ride. It was 40F and I had rode out a mile or two from my house. Started decelerating from about 50 mph and decided to lean back and stretch out my back for a sec. I let go of the handlebars, like I have done many a time.

This is the first time that I have seen the handlebars go from steady to a wobble. At first it was a little vibration and then I saw that the amplitude kept increasing!

Obviously I just clamped back on the grips and that stopped the wobble - very, very freaky.

Here is what I can tell you:
With Progressive springs, zero pressure and Synthetic ATF for fork oil, the front end can be a little bouncy until the oil warms up.

It was cold, so I doubt the tires were warmed up. The road surface was 40F as well.

The bike was decelerating in third gear.

I ended up leaning back a bit, so I shifted my weight (230 lbs) to the back.

I have not experienced this before and I have just gone through the Morely bounce adjustment, new tires, etc, etc.

My thought is that the cold was a factor - both tires and cold fork oil.

Just putting out another data point on the whole wobble thing.

Ps - I have had my bike up to 100 mph both single and two up with no high speed wobble issues. Haven't gotten a chance to go faster yet.




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[blaxmax]

I think we have different definitions of "ride." :confused2:
I have 4 -6 riding events each day. That's a lot of pressure checks each time.

I'm talking about the 1/4 mile.