100mph+ wobbles...what would you do?

[Mightymouse]

Hey guys,

I have a 1997 with 65,000 miles. Stock suspension in the rear, progressive springs in the front with no lowering kit. Forks are filled with ATF fluid.

The bike gets "wobbly" on sweeping highway turns above 90mph. It also wobbles on straight-aways above 105mph. (Both rear suspension coil "settings" are at 2). What would you do to lessen/eliminate it?

 

[Radioguylogs]

In the order of probable causes as I would imagine them:

(1) Tighten steering bearings

(2) Check wheel balance

(3) Check swing arm for tightness and make sure it is centered in the frame properly

(4) Check wheel bearings for abnormalities- loose or erratic movement

I've had the same issue before. I think my loose steering bearings was the main cause, and a sticky rear wheel bearing contributed.

 

[user 16790]

fit wider bars and hold on tighter

 

[Fire-medic]

First, check the steering head bearings (Sean Morley's video on fork 'flop'), rear swingarm pivot, and fluid level, fork oil level and weight-value in the forks, and wheel bearings f & r.

Not inexpensive, but switch to radial tires. Typically you need a new rear wheel. There are 15" radials, but they aren't made for VMax speeds, they're scooter tires. An 18" wheel is closest to the VMax rear tire/wheel height. A 17" wheel is shorter, and gives you more choices of rubber, as it's the most-common sportbike tire size. It has the effect of a gearing change, because of its shorter height. This will cost you a bit of top-end, but how many times are you doing 149 mph? (factory max. speed, stock)

You can use a 18" front radial, but you should refrain/abstain (don't do it) from a 'mix & match' of different radial tires, even from the same manufacturers. Because of differences in construction of the tire carcass, and in tire rubber compounds, if you use not-compatible radial tires front/rear, you may end-up with an evil-handling motorcycle.

Aftermarket wheels in both 17" and 18" are available, front and rear.

https://www.vmaxforum.net/threads/18-x-5-1-2-rear-wheel.41081/#post-429130

https://www.vmaxforum.net/threads/17-rear-wheel.46913/#post-470457

 

[Traumahawk]

I had the same issue and hunted the cause for years. It was actually loose swing arm bearings.

 

[Lars-Erik Andersson]

Hey guys,

I have a 1997 with 65,000 miles. Stock suspension in the rear, progressive springs in the front with no lowering kit. Forks are filled with ATF fluid.

The bike gets "wobbly" on sweeping highway turns above 90mph. It also wobbles on straight-aways above 105mph. (Both rear suspension coil "settings" are at 2). What would you do to lessen/eliminate it?

Hi Me an "old Swede" (67 today) with over 50 years of motorcycling and I have seen all of that handling problems in the 1980-90 on nearly all motorcycle design; doesnt matter what manufacturer….. (excuse me not Ducati and ?)
To try to solve this is not easy but first is changing to the WORLDS Best studs in end and front to parts from famous Swedish Öhlins Company ; It will help you a lot but cost a hell of Money......
Doesnt matter ? Do IT You will be satisfied !
Frame change ? ???
Good luck
/Lars -Erik

 

[Deuce57]

I'm surprised nobody has just said "quit riding at 100 mph", lol. I got mine up to about 125 a few weeks ago, and it felt rock solid. I would have pushed it further, but something told me to back down, so I did.

 

[Zeus36]

My high speed wobble was caused by the rear tire on my 1996. Put on a Shinko 180 and that fixed it. I thought it was front end or neck bearings.....
What tires are you running? How old?

 

[[email protected]]

I've seen countless threads regarding a front end wobble over the years. There is a surprising amount of fixes I've seen posted up.
Steering bearing adjustment, tire replacement, tire balance, swingarm bearing adjustment, wheel bearing replacement, windshield removal, etc...
Steering bearing adjustment fixed mine.

A stock Gen1 vmax is going to flex while cornering. Its totally different than the front end wobble. Solid motor mounts, a reinforced swingarm, and frame braces all help with eliminating it.

 

[C2protect]

Go 105 then. I had my 1985 VMAX up until a hundred and seventy-five thousand miles were on it. And no matter what I ever did it would wobble and sweeping corners and sometimes and hard straightaways. Unfortunately this is a characteristic of the steel-framed first generation VMAX. Larger-diameter front tire sometimes larger-diameter rear tire as well. And sometimes nothing helps. Or tap you REAR brake.

 

[mavgrab302]

Hey guys,

I have a 1997 with 65,000 miles. Stock suspension in the rear, progressive springs in the front with no lowering kit. Forks are filled with ATF fluid.

The bike gets "wobbly" on sweeping highway turns above 90mph. It also wobbles on straight-aways above 105mph. (Both rear suspension coil "settings" are at 2). What would you do to lessen/eliminate it?

Someone has already said it “tighten/replace triple tree bearings”.. that will likely fix it. Fixed mine when i had the issue.

 

[Lars-Erik Andersson]

Sorry but best is to run it not over 70-80 mph and use std Components on it and be glad over the other good Vmax generation1 issues ; Your first up to that speed from zero in many cases and thats enough !!!
Its a 1980 japanese bike.... they are nearly all not built for running faster than 100 mph and higher; just look at dimension on front end tubes and other dynamic parts...( modern 125 cc have front ends with dia 2-5 mm wider )
Buy a generation 2 if You will be safe over 100 + or the best buy a bike made for high speed travelling this is not a Vmax issue at all ….next redlight and win….. me just 67 but like acceleration as hell !
/Lars

 

[Woody]

Solid motor mounts. Helped my 85.
Them stock motor mounts.allowed the motor to move. Now motor and frame.Are solid. No wobbles,shakes or shimmy.
Just saying solid mounts.are worth checking into.

 

[Lars-Erik Andersson]

All Your instructions to improve bad performance are good…. but whats left after ? Vmax gen1,its a 1980 bike no more argueing about that … me owned both honda cbx 1000 and Yamaha xs 1100 and Vmax -92 ....they are the worst bikes in around 1980 but today…. its a joke they cant compare to a new bike with half of that cubic.
//Lars

 

[Woody]

The vmax was built .to win drag races.And it still does .
Funny thing no one .will ever come up to you and say."oh thats a vmax.those are slow"
Just like a corvette.new ones are faster.(sometimes)
But old ones get respect..

Imo a gen 2 rider.who bashes gen 1's. Is a band wagon vmax owner.who doesn't know .what started gen 2's.

 

[Zeus36]

I forgot about frame braces and solid motor mounts. Also a steering dampener may help.

 

[Tom Determan]

Although there's a lot of good ideas on how to fix it, they all cost money. Skip the witch hunt and spending a lot of money. Just give it more gas and power through it. If it still wobbles just hold on tighter.

 

[mavgrab302]

I had a bad wobble in both my first gens..tighten the triple tree bearing or replacing them and lowering the front always fixed mine. If you want to spend money go inverted..

 

[Fire-medic]

I had a bad wobble in both my first gens..tighten the triple tree bearing or replacing them and lowering the front always fixed mine. If you want to spend money go inverted..

Having had friends with inverted fork Gen 1's, my opinion is that running radial tires is the single biggest improvement you can make. The difference in how-precise the handling is, once you switch, is remarkable. Running the bike after the switch, through your favorite twisties will reveal the difference in short-order.

 

[Lars-Erik Andersson]

Having had friends with inverted fork Gen 1's, my opinion is that running radial tires is the single biggest improvement you can make. The difference in how-precise the handling is, once you switch, is remarkable. Running the bike after the switch, through your favorite twisties will reveal the difference in short-order.

Good remark have the same experience with my Honda cbx 1000-78; with new modern tyres from one of the few good suppliers make a hell of difference….. so dont buy first and lowest price, go out and "goggle tyres for your bike mark" then read carefully…..then deside….good luck!
//Lars