Cure the wobble...

Bowsh

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Non-VOC Member
Just watched this brilliant clip by Murray Walker. Got to say “the rider has balls”. A great tip for those high speed wobbles!

 

davidd

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There are lots of different ways to get into a wobble. It does not seem possible to eliminate all of them. The Vincent was subjected to some extra scrutiny because it got a reputation for wobbling. Although you can't eliminate all causes, there is no good reason not to eliminate the conditions that may induce a wobble, such as breaking the link between braking and the front end seizing.

Ultimately, most wobbles seem to have one thing in common: the front getting light. This can happen almost imperceptibly when the front end seizes and the tire starts to "patter" or it can be intentional as in the many wobbles that happen when a wheelie touches down a bit out of alignment with the rear tire. However, you can also just whack one grip of the handlebars and induce a wobble with no weight change at all.

The Murray video is very interesting, but when he said to lean forward to change the weight on the front end it sounded like it made sense if you want to thwart a wobble. I think doing so may change the center of gravity a bit even though much of the weight is still going through the seat. But, I thought Murray was wrong. The rider, when getting into a tuck is changing the center of pressure, not so much the center of gravity. I thought it had more to do with aerodynamics causing a change in pressure than weight shifting causing the change. It seemed to me that when you are upright you are presenting yourself as a giant sail and that sail is in front of the center of gravity. That is a recipe for disaster because a lot of instability is created when the CoP is in front of the CoG in an airplane, car or motorcycle. When the giant sail goes away on the motorcycle by tucking the instability goes away.

I don't know enough to know if this is correct or partially correct, but Bill might be right. You may have to pass on the sweets after all.

David
 

Bill Thomas

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Some say the 4 cylinder engine, Across the frame, Was a problem, Like running into the wind holding a bit of cardboard.
But to say nothing will happen if you stay under 70 mph is wrong.
I got thrown over the top at well under 70, And at another time on another bike, Had a bad weave at 50 ish.
On my Comet I had a Huge tank slapper at well under 70, After hitting a pothole while pushing on through a bend, Got away with that one, Don't know how ?, Pure luck.
I am sure a good Hydraulic steering damper, Would have sorted all the problems shown.
Cheers Bill.
 

Bill Thomas

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VOC Member
Thanks for that Vincent, Can you show us how, I didn't think you could fit one to Bramtons.
Cheers Bill.
 

Bowsh

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Non-VOC Member
I’m no expert re aerodynamics. If Murray says more weight up front, then it’s a tank bag full of sweets for me..
 
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