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

[brian hicks]

After removing the stiff springs and replacing with the original progressively turned softer springs in my front suspension (43mm.) I found that the bike is more upright on the side stand so there is obviously a bit more sag. I have also removed the 1 inch drop that I had set on the front fork positioning and put it back to the top and set my rear YSS suspension to minimum pre load. I can confidently do 100mph on most roads now before the weave starts. With the original OEM rear suspension I found that changing rebound from 1 to 4 made a big difference for the better. I still think that the route cause of the problem is an oscillating frame at a resonant frequency and the answer is either to brace the frame with welded gussets or try and disrupt the resonance with the experiments that we have tried. My bike has 21000 miles on the clock and is around 1999 model.

 

[wayne billings]

Hello Brian Hicks Try Sean Morleys steering head bearing adj. (youtube), check all motormounts.factory torque specs. If thats not enough, solid motor mounts, I have done these things and have no wable up to 115 mph. The best to you . P.S. I think exact rep sells them

 

[MaxMidnight]

I found that the bike is more upright on the side stand so there is obviously a bit more sag.

If the OE springs results in the bike being more upright wouldn't that suggest less sag?

 

[Shuriken]

I definitely noticed that when bouncing the rear suspension with damping set at 1, I hear damping sounds. If I set at 4, I hear nothing. To me, that means that setting 4 places more restriction on the damping ports (closure?) so that the shock damping happens at a slower speed, because the oil takes more time to flow through less or smaller ports. I don't know this as fact and I might be wrong; it just seems like the observed response.

Since riding 2-up with the extra weight of the passenger stabilizes the bike, and since nothing else I have tried has made as much of a noticeable difference as this, I am focused right now on finding a way to simulate 2-up riding. Either I add a lot more weight, or I see what I can do to lower the rear 0.5-1" for testing.

Unfortunately, I am limited in my options for this. I don't have any 12.5" shocks in the spare parts pile, and since I am experimenting, it doesn't make sense to buy a new set when there is a risk it won't solve the issue.

The least expensive option I have right now is to fabricate some solid 12.5" struts out of steel tube and test ride.

I have arrived at the conclusion also that if I weighed 275, this bike may ride perfectly on the OEM configuration, as-is. Unfortunately, I don't know any 275lb riders in my area who could test ride for me and prove my hypothesis.

 

[brian hicks]

Hello Brian Hicks Try Sean Morleys steering head bearing adj. (youtube), check all motormounts.factory torque specs. If thats not enough, solid motor mounts, I have done these things and have no wable up to 115 mph. The best to you . P.S. I think exact rep sells them

I tightened the steering bearings a few months ago and it made a big difference to the high speed shake. I haven't checked the swing arm tightness so maybe that's a job for the future.

 

[MadMark]

I've been watching this thread for awhile an seen many suggested fixes.
But have you made sure everything's square wheel wise,
vertically and horizontally.
It could be as simple as the forks being not square an is in a bind. Or the rear swingarm is compromise somehow.
What I don't understand is why there's isn't
video of problems. I had a high speed wobble an it was fixed by tightening the head bearings. I know you already tighten the head bearings, but did you tighten it enough?
I guess you could always buy a steering stabilizer an probably fix your 115mph problem.
It's just insane you have spent so much time trying to figure it out.
It's really depends on how far you want to go an keep throwing money that a steering dampener would probably fix it.
I'd sell this bike for parts because of the high speed wobble.

 

[Shuriken]

I might.

But then I'd still have to find and buy another vmax. There just isn't anything like it..... and that's why I like it.

I've been eying the Gen 2s but I don't see deals.

In contrast, I see nice BMWs all day long for great prices. Why do all the beamer riders put up their bikes for sale?

I will be trying some 12.5" solid struts soon and will post results.

 

[MaxMidnight]

I will be trying some 12.5" solid struts soon and will post results.

...once your eyes stop bouncing around your head!?
IMO not a good idea particularly at the speeds you need to test it at.

 

[Shuriken]

...once your eyes stop bouncing around your head!?
IMO not a good idea particularly at the speeds you need to test it at.

I agree. But I've ride tested so many times now that I may just be able to determine all I need to know at 65.

I am also not offended by any opinions offered that I should sell the bike. I have sold and moved on from quite a few bikes over the years and am sure I could sell this one locally if I run out of patience. The bigger issue would be finding locally for sale another on in better condition. And other than the issues at speed, this bike is in great shape for its age, and now, has all new bearings, tires, brakes, etc. Might have to do a road trip to find something nicer.

 

[Skycopper]

Just in case anyone remembers the FURBUR FIX, I have a complete set of, spanner, custom made socket, and many solid copper washers available, if anyone wishes to go that route. I'm NOT advocating this as a solution for anyone, but it did fix my 98 permanently. Don't waste your time and energy telling me how wrong it is to do this. The issues has been flogged for decades.

 

[Shuriken]

Something awesome happened today.

I got to ride a 92 model. Forgot there was one around.

First thing I did was a front end inspection and comparison. And absolutely was shocked at how much more solid the front end felt... handlebars measured about 27.75" wide grip end to end and felt stiff. Mine measure over 30" grip to grip and feel not as stiff. His bike feels heavy leaning into low speed turns and mine feels to me, easy, and light....

 

[brian hicks]

Tightening the steering bearings on my 98 model stopped the shake but not the weave. Fitting stronger fork springs and setting the rear pre-load a couple of steps harder made the ride hard but did nothing for the handling. Now I'm back to softer springs and settings for a gentler ride.

 

[Shuriken]

Tightening the steering bearings on my 98 model stopped the shake but not the weave. Fitting stronger fork springs and setting the rear pre-load a couple of steps harder made the ride hard but did nothing for the handling. Now I'm back to softer springs and settings for a gentler ride.

Do you have OEM handlebars? Can you measure width?

 

[MadMark]

Do you have OEM handlebars? Can you measure width?

I measured 27" to the center of the ends, since there angled. Without any grips, handlebars only.

 

[brian hicks]

Do you have OEM handlebars? Can you measure width?

28 inches.

 

[Shuriken]

OEM handlebars made a small difference. Tightening head bearings a little more made another slight positive difference but even a degree more will be too tight. Got to 100 and thought that was decent, as I can pass on the freeway a tad better. But then it started running crappy days later and I'm out of riding season. I can't declare a fix and now believe it's just something with that particular bike.

However.... I've since test ridden two different year vmax bikes, and the steering feels much different.

For example, I rode an 03 up to 105 and it feels smooth and safe. NO HIGH SPEED WOBBLE.

Funny thing is, the 03 has the 45mph decel wobble!

 

[retrosdad]

Yamaha factory should be the one using their immense resources to finally solve this problem. It is sad to see many different VMax owners, over several decades, report the wobble problem. Yet it goes on. Owners offering wildly different and various theories about the wobble problem, what might cause it, and what might fix it. Yamah factory stands on the sidelines and says nothing.

 

[Shuriken]

I have an 03 in my garage at the moment. I've been trying it out.

My 85, when running well, after all the work I've done to it, runs every bit as strong as the 03, maybe moreso with leaner jets. It shifts waaay smoother than the 03, which may need the shift fork adjusted. Doesn't like neutral.

But.... the 03 is better cosmetically and has some nice upgrades.

.....and.... it.... does.... not.... wobble... at... high.... speed...

I gave the steering head a 1/4 turn tighter, which cleared up the 45mph decel wobble. While testing, it easily pulled 115 with no issue. Doesn't even wiggle crossing over the dotted line when changing lanes to pass. Tires are Avon Venom at 33 and 36psi.

I doubt any previous owners of the 03 ever touched the steering head. The nuts don't even have a mark on them. When I went to loosen the chrome bridge nut, it was waaaaaaay less tight than I expected, as in maybe 20lbs. Furthermore, the castle nuts were also nowhere near as tight as on my 85. I think an owner would have had the 45mph wobble fixed before me, so I think this may have been factory torque. Crazy.

I wish I could wrap this thread up with a concrete solution. I haven't given up but may be done for the season.

The one thing I didn't have time or money for at the moment was to try the solid motor mounts. Hopefully I'll get time for that later but if anyone else reporting issues on this thread wants to try solid mounts first in a long list of many things, let us know how it goes.

Me: 0
85 high speed instability: 1

 

[MaxMidnight]

When I went to loosen the chrome bridge nut, it was waaaaaaay less tight than I expected, as in maybe 20lbs. Furthermore, the castle nuts were also nowhere near as tight as on my 85. I think an owner would have had the 45mph wobble fixed before me, so I think this may have been factory torque. Crazy.

I may have mentioned this before but I have found that if this is tightened to the factory spec (Steering Crown Steering Shaft M22x1.0 110Nm 80ft/lb) then it adds additional pre-load to the bearing and they are then too tight.
What I do is adjust them to the correct spec with the two lock rings and then, with the front wheel off the ground, use a spring gauge to measure how much effort is needed to pull the forks off the bump stops.
The top nut is tightened until the effort needed to move the forks is the starts to go over that previously measured and then backed off a tad. I've never had it loosen and never experienced weaving.
May be a coincidence but who knows?

The value you have measured on your '03 is probably similar to what I use.

 

[brian hicks]

I have an 03 in my garage at the moment. I've been trying it out.

My 85, when running well, after all the work I've done to it, runs every bit as strong as the 03, maybe moreso with leaner jets. It shifts waaay smoother than the 03, which may need the shift fork adjusted. Doesn't like neutral.

But.... the 03 is better cosmetically and has some nice upgrades.

.....and.... it.... does.... not.... wobble... at... high.... speed...

I gave the steering head a 1/4 turn tighter, which cleared up the 45mph decel wobble. While testing, it easily pulled 115 with no issue. Doesn't even wiggle crossing over the dotted line when changing lanes to pass. Tires are Avon Venom at 33 and 36psi.

I doubt any previous owners of the 03 ever touched the steering head. The nuts don't even have a mark on them. When I went to loosen the chrome bridge nut, it was waaaaaaay less tight than I expected, as in maybe 20lbs. Furthermore, the castle nuts were also nowhere near as tight as on my 85. I think an owner would have had the 45mph wobble fixed before me, so I think this may have been factory torque. Crazy.

I wish I could wrap this thread up with a concrete solution. I haven't given up but may be done for the season.

The one thing I didn't have time or money for at the moment was to try the solid motor mounts. Hopefully I'll get time for that later but if anyone else reporting issues on this thread wants to try solid mounts first in a long list of many things, let us know how it goes.

Me: 0
85 high speed instability: 1

The first time I checked the steering on my 2007 Vmax it was far too loose with the forks bouncing off the stops when I jacked up the front end. After I had tightened them I found that it had got rid of the fast shaking at 85Mph but I'm still stuck with the frame wobble at around 90Mph even though I have fitted frame braces, though I can get to about 110Mph if I'm careful. If I hit a bump the whole thing goes into oscillation. The riding season is over now here in UK so I will try again in 6 months.