Shuriken
Well-Known Member
No, I don't mean to shake yourself into a speed wobble or an accident. But I would like to know what your bike does and if it is stock or modified as far as suspension is concerned.
If I do this, the front end continues wobbling at 2 or 3 times per second for a few seconds until the wobble settles out.
Other characteristics of the suspension on my bike:
- 75mph sweepers consistently cause a wobble. Feels like the tire is trying to dive/oscillate into the turn.
- Merging onto the freeway at 75-95 causes a wobble.
- Passing a car or string of cars on vboost causes a wobble.
- Attempting a top speed straight line blast causes a wobble. This wobble starts out as a slow/wobble/weave that gets worse as speed increases. It starts somewhere around 75-90 and does not stop *unless I firmly and equally push the handlebars forward*
My bike also had the 45mph decel wobble until I replaced the tires. It no longer has the 45mph wobble.
So..... back to the thread title. What does your bike do if you wiggle the bars at speed? It shouldn't continue oscillating. If it does, what is the cause?
Turning one direction would increase spring tension on one fork and decrease tension on another fork, right? If fork tension is not equal, the spring in the fork will eventually push back in the opposite direction. This would continue until both forks have equal spring tension, right? The oil is supposed to reduce the speed of this effect / provide damping, right?
If this is all true, it would seem to be a fork damping problem on my bike, for one. Maybe other problems also, but it is important to change only one thing at a time.
**Does anyone with racetech emulators have any kind of wobbling problem?
**Does anyone with aftermarket forks have any kind of wobbling problem?
To simplify the problem, if you modify the front end/forks/steering head and never have the wobble again, we eliminate swingarm and rear suspension as major factors.
I bought a small truck once that had blown shocks. When you went into a turn at highway speed, the truck wanted to violently roll. If you performed a L to R wiggle of the steering wheel, the truck became unstable.
I've removed and tested old/worn out rear shocks from various bikes I've owned. You know, where the seals wear out and the oil seeps out. When you start depressing the shock up and down, all you feel is spring tension and a lot of bounce.
This is my first theory with my bike. I *do* have some replacement forks from an '88 that have been lowered I believe. As soon as I get some time, I want to just swap the forks and test.
Finally, I would like opinions on what you all think that pushing equally and firmly forward on the bars during a speed wobble does exactly to stop the wobble. Is it loading the rear suspension more? Increasing steering head bearing tension?
If the primary result of this action serves to increase steering head bearing tension/seating, then I may just order factory bearings and go that route before the front end swap.
If I do this, the front end continues wobbling at 2 or 3 times per second for a few seconds until the wobble settles out.
Other characteristics of the suspension on my bike:
- 75mph sweepers consistently cause a wobble. Feels like the tire is trying to dive/oscillate into the turn.
- Merging onto the freeway at 75-95 causes a wobble.
- Passing a car or string of cars on vboost causes a wobble.
- Attempting a top speed straight line blast causes a wobble. This wobble starts out as a slow/wobble/weave that gets worse as speed increases. It starts somewhere around 75-90 and does not stop *unless I firmly and equally push the handlebars forward*
My bike also had the 45mph decel wobble until I replaced the tires. It no longer has the 45mph wobble.
So..... back to the thread title. What does your bike do if you wiggle the bars at speed? It shouldn't continue oscillating. If it does, what is the cause?
Turning one direction would increase spring tension on one fork and decrease tension on another fork, right? If fork tension is not equal, the spring in the fork will eventually push back in the opposite direction. This would continue until both forks have equal spring tension, right? The oil is supposed to reduce the speed of this effect / provide damping, right?
If this is all true, it would seem to be a fork damping problem on my bike, for one. Maybe other problems also, but it is important to change only one thing at a time.
**Does anyone with racetech emulators have any kind of wobbling problem?
**Does anyone with aftermarket forks have any kind of wobbling problem?
To simplify the problem, if you modify the front end/forks/steering head and never have the wobble again, we eliminate swingarm and rear suspension as major factors.
I bought a small truck once that had blown shocks. When you went into a turn at highway speed, the truck wanted to violently roll. If you performed a L to R wiggle of the steering wheel, the truck became unstable.
I've removed and tested old/worn out rear shocks from various bikes I've owned. You know, where the seals wear out and the oil seeps out. When you start depressing the shock up and down, all you feel is spring tension and a lot of bounce.
This is my first theory with my bike. I *do* have some replacement forks from an '88 that have been lowered I believe. As soon as I get some time, I want to just swap the forks and test.
Finally, I would like opinions on what you all think that pushing equally and firmly forward on the bars during a speed wobble does exactly to stop the wobble. Is it loading the rear suspension more? Increasing steering head bearing tension?
If the primary result of this action serves to increase steering head bearing tension/seating, then I may just order factory bearings and go that route before the front end swap.
