Got the Wobbles

[gunrunner]

Went for a blat on my bike and at just over 100kmph on a sweeping bend going over a bridge came across whats known as the "Death Wobble" gave me the shits , have info on the Furbur Fix which is changing the steering nuts by taking off the trees and steering , has any one done this and is it as easy as it seems

[captain_andrey]

I've had a massive speed wobble when I pulled out to pass a car and ran over some cats eyes. Scared the hell out of me.

[Katman]

have info on the Furbur Fix which is changing the steering nuts by taking off the trees and steering , has any one done this and is it as easy as it seems

With all due respect, if you're talking about the steering head bearings, your post would suggest the job is beyond your capabilities.

[vifferman]

If this is the only manifestation you've had of a tank slapper, then don't worry about it. Otherwise, or if you're really worried, get a shop to fit a steering damper.

[nodrog:Me]

If this is the only manifestation you've had of a tank slapper, then don't worry about it. Otherwise, or if you're really worried, get a shop to fit a steering damper.

or get them to check the "steering nuts" and adjust or replace as neccesary.

[Kiwi Graham:Me]

Check tyre pressures and condition, stearing head bearings, rear suspension (is it even,too soft or one leaking?). Dont forget nailing a big horse power bike is going to upset the front end especially on an uneven surface, back off slightly and/or reduce the grip on the bars, transfer your weight forward a little and she will come right. If it freeks you out too much et a stearing damper. A little shake now and then is her way of letting you know she is still there

[MSTRS:Me]

Check tyre pressures and condition, stearing head bearings, rear suspension (is it even,too soft or one leaking?). Dont forget nailing a big horse power bike is going to upset the front end especially on an uneven surface, back off slightly and/or reduce the grip on the bars, transfer your weight forward a little and she will come right. If it freeks you out too much et a stearing damper. A little shake now and then is her way of letting you know she is still there

Not so sure about that. In a true tank slapper, getting some weight off the front is the trick. It is happening because the front tyre is biting off centre, the bike does not like that and tries to compensate by 'changing sides'. Of course all that happens then is a pendulum effect, which is worsened by adding weight. I was always taught to sit back slightly, relax the grip and even accelerate slightly. Mind you, I've never had a true tankslapper...just a violent headshake that was fixed by doing the above.

[Pwalo]

Check out what the others have indicated, but remember that the VMax was renowned as being a bit wayward in the handling department.

You may just have found the limits of what the old bus is capable of.

[Kiwi Graham:Me]

Not so sure about that. In a true tank slapper, getting some weight off the front is the trick. It is happening because the front tyre is biting off centre, the bike does not like that and tries to compensate by 'changing sides'. Of course all that happens then is a pendulum effect, which is worsened by adding weight. I was always taught to sit back slightly, relax the grip and even accelerate slightly. Mind you, I've never had a true tankslapper...just a violent headshake that was fixed by doing the above.

I hear what you say . But... I based my answer/advice on 30+ years riding a bike from motorcross (as a kid) to road (still doing it) to circuit both europe and here inc IOM (very bumpy!). I dont profess to knowing it all by any means its just what has worked for me. Binklebonk, check the sticky thread in 'survival skills' for a more indepth answer to you question mate.

[MSTRS:Me]

Could this guy have saved it?
http://www.youtube.com/watch?v=ymvVv_zbOjk

[vifferman]

Not so sure about that. In a true tank slapper, getting some weight off the front is the trick. It is happening because the front tyre is biting off centre, the bike does not like that and tries to compensate by 'changing sides'. Of course all that happens then is a pendulum effect, which is worsened by adding weight. I was always taught to sit back slightly, relax the grip and even accelerate slightly.

Hmmmmm....
I too have never had a true tankslapper, but the only times I've had any bike waggle the bars has been when accelerating hard, so the front end was already light. As all the bikes this happened on didn't have very steep steering angles, they all recovered by themselves by the time I noticed.
The only exception to this was a VF500 I used to have, which had a 16" front wheel. It waggled the bars once over ripply road when accelerating hard, and that was it. However, I had a Dunlop front tyre with a fairly triangular profile, and the bike didn't like it. I dunno if it wasn't ever balanced properly or what, but if I relaxed my grip on the bars, or took one or more hands off, it went mental. The problem disappeared when I went back to an ME33 front tyre with a rounder profile. I was told by the bike dealer that fitted it (who'd worked for Honda and had a VF500 himself) that the VF was picky about what front rubber was fitted.
The VFR750 was also sometimes prone to the same thing - only when going downhill, power off, hands off the bars, and doing 70 km/h. It seems that the cause was a combination of head bearing wear, tyre type and wear. The VFR750 tended to get uneven wear on the front tread as (like other bikes such as the Blackbird) it weights and pushed the front tyre in turns.

[Kiwi Graham:Me]

He didn't save it?? I spoke to him after this, he was riding a fireblade. It scared the shit out of him and thankfully suffered only bruises and friction burns. various reasons for this were concidered and it was felt that the15mm jack up kit fitted to the rear (a common mod to make blades turn in faster) together with the ??mm cant remember fork drop through the yokes coupled with a 16" wheel led the this result. He had been fighting instability all week and at this part of the circuit (Bray Hill) it is a very fast down hill bumpy 150+mph section flanked by stone walls. He was very lucky! I dont think anyone would claim all tankslappers are saveable, those of us with some experiance can only give our advice on things you can do to to help save the situation. Clearly in this case ie 150mph, inherently unstable bike and being frozen by fear of the events unfolding led to this happening.

[Buster]

The bikes geometry shouldnt be a problem. Its probably more like a fucked tyre or worn bearing issue. It needs to be checked over by a mechanic for a start. Bearings are very cheap and you might find out some other useful info.

At least you made it through a hairy situation

[MSTRS:Me]

Hmmmmm....
I too have never had a true tankslapper, but the only times I've had any bike waggle the bars has been when accelerating hard, so the front end was already light.

Strangely, this was what I was doing in that one incident of headshake....
Accelerating hard. Ripples in the seal - sort of corrugations at 90 degrees to travel. Sure raised the heart rate.
That IOM clip is a great example of the extreme tankslapper. I don't think the guy could have done anything. I would assume that as a race bike, it had a damper fitted, so the forces that created/sustained it have to be huge. One would hope that degree would never be encountered on the road, even if getting a little carried away.

[_intense_]

// EASY FIX #1: just ride round on one wheel all the time bro... (plus you'll save on buying rubber)