V-Max Speed Wobble (ran it up to 115mph and...)

[retrosdad]

Death wobble begins with sideways motion. The first thing to create that is the 90 degree angle in drivetrain. That transfers to rear fork and engine mounts primarily. A quality set of polyurethane bushings will solve most of the erratic behavior. I decided to go full polyurethane and never had wobble issues after. Steering damper is a good idea too. Just my two cents.

Do u mean “ transfers to the swing arm? Some Triumph motorcycles came with built in factory fork dampers. I had one but never needed it since my 1955 650cc Triump would not run much over 100mph or so. I always thought fork steering dampers were no longer needed due to great advances in motorcycle design engineering hahaha. You have an interesting theory about the high speed wobble starting in the 90 degree drive shaft angle. We all know that, when leaning for a sweeping curve, a shaft drive motorcycle will try to “squat “ while in that curve if you pour on the gas. And by doing that “squatting,” that will add downward rear wheel traction and at the same time cause a small attempt at “lifting” and some loss of traction on the front wheel. Maybe in straight line high speed riding, when wind resistant already wants to cause some front wheel lift, what with the high power being applied through that 90 degrees you mentioned, maybe that causes some intermittent lift which causes the death wobble. I would like to know if any VMaxs that are converted to chain drive, ever experience the death wobble. JMHO

 

[Shuriken]

Death wobble begins with sideways motion. The first thing to create that is the 90 degree angle in drivetrain. That transfers to rear fork and engine mounts primarily. A quality set of polyurethane bushings will solve most of the erratic behavior. I decided to go full polyurethane and never had wobble issues after. Steering damper is a good idea too. Just my two cents.

I'm not clear what you mean by bushings. Are you saying motor mounts or suspension mounts or something else?

 

[Shuriken]

I suggested a steering damper, but you didn't seem interested.
lots of sports bike have them for extreme speed riding which is what you're doing.
i installed one and it fixed any wabble in my bike.

Thanks for this reminder.

I am indeed interested.... but my hope was to solve the base issue first and then move toward a damper as the ultimate hail mary last resort play.... I'm quickly getting to that because all of my running plays are getting stuffed at the goal line...

From my reading, many of the high speed racing bikes use them even when the bikes are already more stable at speed. For example, lofting the front wheel and then setting it down can cause the death wobble on those racing bikes so it becomes a must have.

I have no intention or interest in high speed riding aside from a track. But having a bike than can do 120 safely means safety on the interstate at 75-90, when entering the freeway, when passing tractor trailors, etc.

If it's solid at freeway speed with some room for passing, that will do.

 

[retrosdad]

When you come into a high speed wobble you want to get the weight off the front, Its disaster if you hit the brakes during a high speed wobble. You want to whack the gas and get the weight off.

What do you do when forced to unwhack the gas and weight and pressure is suddenly and forceably returned to the front wheel?

 

[retrosdad]

So I bought my 06 max last year from my local dealer. The bike was brand new out of the crate 3 years old (got a good deal on it). Anyway i still have the factory warranty on the bike and i've complained abou the wobble i get over 100 mph and they told me they couldn't find anything. i want to bring up the proper torque you brought up but but do you know the spec for them so i could tell them. i don't really have much faith in them because i took it in for my first service and i couldn't tell they did anything besides change the oil.

PS Any good shops in NJ i can use???

“Can’t find anything” is probably what they tell everyone who complains, while still under factory warranty, about a high speed wobble. Such a phrase is a case of using Weasel words” to get out from under providing free warranty work to determine the actual problem. After your warrant is over, and you complain, they probably would charge you big bucks to actually find the problem. Either that or give you a big bill detailing charges of all they did and still didn’t find any problem.

 

[retrosdad]

+ 1 to what Garrett wrote, and I usually loosen up the bolts on the lower triple clamp hat hold the fork tubes also during the tightening process.

How often do you have to do this?

 

[MaxMidnight]

Death wobble begins with sideways motion. The first thing to create that is the 90 degree angle in drivetrain. That transfers to rear fork and engine mounts primarily.

Sorry if I'm being a bit dense here but I'm assuming you are referring to the 90° in the middle gear and it is this that induces a wobble?
As as I can work out the first interaction that the power train has with the frame would be at the final drive. While this may cause the suspension to rise or fall depending on the amount of torque put into the system this would be at 90° to any sideways motion.
Given that not all Maxii have the issue can that be the cause?

 

[Shuriken]

What do you do when forced to unwhack the gas and weight and pressure is suddenly and forceably returned to the front wheel?

When the wobble/weave happened to me so many years ago, when I was far more inexperienced with this bike, it was highly unsettling... downright scary. First time I'd ever experienced a high-speed wobble/weave on a bike. I'm experienced enough now to feel the onset of the danger area.

The vintage video links I posted showed success when lying down over the tank to settle the bike down but in cases where it happened to me, I had to gently back off the throttle while gently involving the rear brake and leaning more up, in coordinated fashion. I'm talking feathering actions. Any of those actions independently done too quickly seems like it will make it worse.

In a full-on headshake / tank slap scenario, the videos I've studied online show the violence of the physics at play and the advice I've read is to grip the bike with your knees and let it settle itself out. 5-6 cycles per second of that violence is just too fast for the average person to settle out with muscle and I think it could break your wrists or just buck you off the bike for trying.

I've been retroactively following with great interest this other thread and learned a lot about the violent tank slapper from user Lotsokids, but he hasn't posted to that thread in years, and right when he started making some progress (last was by changing out the handlebars), he went radio silent on that thread. His last post to that thread said, "If the wobble returns as bad as it was, I don't think I could control it and end up in the hospital or in the ground." Last seen 4 years ago. I really wanted to see how he fared with new handlebars, but....

 

[retrosdad]

When the wobble/weave happened to me so many years ago, when I was far more inexperienced with this bike, it was highly unsettling... downright scary. First time I'd ever experienced a high-speed wobble/weave on a bike. I'm experienced enough now to feel the onset of the danger area.

The vintage video links I posted showed success when lying down over the tank to settle the bike down but in cases where it happened to me, I had to gently back off the throttle while gently involving the rear brake and leaning more up, in coordinated fashion. I'm talking feathering actions. Any of those actions independently done too quickly seems like it will make it worse.

In a full-on headshake / tank slap scenario, the videos I've studied online show the violence of the physics at play and the advice I've read is to grip the bike with your knees and let it settle itself out. 5-6 cycles per second of that violence is just too fast for the average person to settle out with muscle and I think it could break your wrists or just buck you off the bike for trying.

I've been retroactively following with great interest this other thread and learned a lot about the violent tank slapper from user Lotsokids, but he hasn't posted to that thread in years, and right when he started making some progress (last was by changing out the handlebars), he went radio silent on that thread. His last post to that thread said, "If the wobble returns as bad as it was, I don't think I could control it and end up in the hospital or in the ground." Last seen 4 years ago. I really wanted to see how he fared with new handlebars, but....

The infamous VMax death wobble has been mentioned in motorcycle magazines, Talked about all over the Internet, etc. Numerous owners have spent excessive time and money replacing stock parts, making various adjustments, offering countless and various theories, etc.. And all the while, perhaps risking or losing their lives while doing their test runs. And since 1985 or so, Yamaha management has remained silent. If truth be known, I betting Yahama engineering dept is aware of the VMax death wobble. I’m also betting they have done some testing research and discovered the cause of the wobble. I am disgusted at Yamaha for ducking their responsible. There is no way to know how many of our brother VMaxers have been killed by the high speed wobble because the death wobble lived up to its name. Meaning the rider and bike were found along along the highway with the rider dead and the death wobble long gone. Just another unexplained motorcycle death. I am somewhat disappointed in my fellow VMaxers being so quick to “own” this problem. The are not the cause of the problem. Yamaha is the cause of the problem. JMHO

 

[wilks]

I'm not clear what you mean by bushings. Are you saying motor mounts or suspension mounts or something else?

deleted

 

[Fire-medic]

I'm interested to see how-many people who own VMax'es and who have changed wheels to allow the use of radial tires, have experienced the wobble so-many people complain about.

 

[MaxMidnight]

And since 1985 or so, Yamaha management has remained silent. If truth be known, I betting Yahama engineering dept is aware of the VMax death wobble. I’m also betting they have done some testing research and discovered the cause of the wobble. I am disgusted at Yamaha for ducking their responsible. There is no way to know how many of our brother VMaxers have been killed by the high speed wobble because the death wobble lived up to its name. Meaning the rider and bike were found along along the highway with the rider dead and the death wobble long gone. Just another unexplained motorcycle death. I am somewhat disappointed in my fellow VMaxers being so quick to “own” this problem. The are not the cause of the problem. Yamaha is the cause of the problem. JMHO

You can believe what you want but repeating the same diatribe doesn't make it true.
This is pure speculation without presenting a shred of evidence of Yamaha's complicity and (IMO) does nothing to help those with the condition.

The cause of serious accidents are always investigated by the authorities to try and ascertain the cause and if the vehicle is found to play a part in it the manufacturer will be involved (e.g. Suzuki SV1000 if memory serves well) and as far as I'm aware that is not the case for Yamaha.
There will also be reports that detail investigations and conclude what the issue was (see here) and there are probably others.
Perhaps you should read the content to establish if it offers any basis to your opinion?

Everybody is entitled to have opinions but I would hope that they would base them on factual data rather than what they would like to be true.

 

[Shuriken]

I'm interested to see how-many people who own VMax'es and who have changed wheels to allow the use of radial tires, have experienced the wobble so-many people complain about.

I've also taken an interest in this. As I understand it, in 2024, there are too few or no cost-effective ways to place a radial tire/wheel on a V-Max due to the weird wheel size. I understand that there are radial tires for the front but moving to a rear radial solution means falling victim to that vicious creature called the Mod Monkey...

 

[brian hicks]

Imagine what would happen if this problem existed in a car. It would have been solved years ago.

 

[VMAXXIMUM]

Most will caution you not to put a radial on the front rim. It’s to narrow. It can be done however it detrimentally alters the tire profile. Better to stick with a good bias ply or get new wheels

 

[VMAXXIMUM]

I may be wrong but although it can be several causes of the wobble, the majority seem to be caused by a too loose head bearing. I don’t see how regular maintenance item could be considered a manufacturer defect as I stated before I had a 55 mile per hour wobble and after properly adjusting the head bearing and yearly checking and regreasing it. It’s never happened again nor has it ever come back As I stated, I regularly have put my bike on the track and not the drag track, road tracks and thrash the hell out of it with no problems .

 

[brian hicks]

d a box on the back of my bike today and took it up to about 95 to test the wobble. It seemed to make it slightly worse. The box weighs about 10K. I think the weight needs to be concentrated somewhere above the swinging arm to stabilise the frame. I am coming to the conclusion that to fix this issue the frame needs to be stripped away from the bike and strengthening gussets welded in to stop the flex. Also the swinging arm could probably be braced also.

 

[brian hicks]

I think the shaft, wheels and frame hit a resonance at about 95Mph. The Tacoma bridge effect. Altering anything on the bike seems to effect it. In particular , rebound dampening on the rear suspension if you have that adjustment and tightening the steering head bearings did a lot for me. Surprisingly, fitting frame braces didn't do a lot but that's probably because the frame is flexing in a different plane.

 

[Shuriken]

I think the shaft, wheels and frame hit a resonance at about 95Mph. The Tacoma bridge effect. Altering anything on the bike seems to effect it. In particular , rebound dampening on the rear suspension if you have that adjustment and tightening the steering head bearings did a lot for me. Surprisingly, fitting frame braces didn't do a lot but that's probably because the frame is flexing in a different plane.

This is possible. I just can't figure out why it does not happen to all v-max bikes...

I still think it's a system of factors. For example, maybe 1mm slop per fork and maybe 1mm of slop in the motor mounts at high speed. So 3mm of springy system slop at 75+ might feel insignificant at 35.

The wheels make a very pronounced gyro effect at high speed. Movements made to turn the bike exert a lot of pressure on front end parts because of the effort required to destabilize the front wheel to make it lean. If the front end, frame components, etc. have too much elasticity, I feel like the bike will feel too twitchy because of the forces at play.

I'm awaiting a 93 front end from a well-running donor. If that does nothing to improve the front end, I can try motor mounts, fork brace, handlebars and then give up.

That will be the day to install a steering damper or not ride on the interstate.

 

[Shuriken]

d a box on the back of my bike today and took it up to about 95 to test the wobble. It seemed to make it slightly worse. The box weighs about 10K. I think the weight needs to be concentrated somewhere above the swinging arm to stabilise the frame. I am coming to the conclusion that to fix this issue the frame needs to be stripped away from the bike and strengthening gussets welded in to stop the flex. Also the swinging arm could probably be braced also.

Great experiment and thank you. You may be right. I used a 60lb / 4 stone backpack and it rested on the seat!