Speed wobbles

[stunz]

well, not really "speed" wobbles but...

I got on the main drag this morning, realised the firking sun was out so got me sunnies out of the tank bag and proceeded to put them on. Of course, to get the arms between my face and the helmet I had to use two hands. I contemplated stopping and doing it but thought it would only take a few seconds to put in place...

Anyway, I must have only been doing 55 I was putting the windows on and the front of the bike starting shaking from side to side like farkin mad!

I've just had new tyres put on, about a week ago fitted and balanced.
The forks were resealed about a month ago and the head bearings replaced.

This hasn't happened before and usually the bike is great for holding its line (if for some reason, I have to remove my hands from the bar. Admittedly, this has only been done at speed, you know, open visor, bee, panic, let go both hands...etc, etc)

Would this imply that the new tyres havent been balanced properly?

[James Deuce]

Nope. every bike has a speed at which the bars will do just that if you let go of them.

http://en.wikipedia.org/wiki/Speed_wobble

Oops! Correct URL now posted - in no way did I mean to imply you are a cretin. Doh!

[Gremlin]

test it a bit more (try revs and speed combinations as well)... You may have hit a slight ripple on the ground, and only having one hand on the bar could have sent it into a touch of headshake. Had that quite a bit.

Some tyres do fight each other as such, which is why matched tyres are recommended (some people don't have issues tho).

Oh, and practise taking both hands off the bar a bit... gives you a good sense of feel for the bike, and how its balanced... slowing to lights is often a good way, but to start off, try downhills...

[Hitcher]

I know what you're doing wrong. You should take your helmet off first before donning eyewear...

[The_Dover]

Nope. every bike has a speed at which the bars will do just that if you let go of them.

http://en.wikipedia.org/wiki/Speed_wobble

Oops! Correct URL now posted - in no way did I mean to imply you are a cretin. Doh!

Yeah, Finn's MV does it at about 30km/h

[SimJen]

my nsr did that once, was riding on a real smooth bit of seal and had completely track shagged BT56SS's on. I had both hands off the bars as I tightened my gloves and the front end went nuts.....could have been a tiny stone I suppose???? Looked cool though

[Lou Girardin]

My bike only does it with a touring load on the back

[Crisis management]

Was it a problem??? All bikes do strange stuff from time to time, relax and enjoy the variety in life.
If it was always boring then we wouldn't ride them would we?

[stunz]

Nope. every bike has a speed at which the bars will do just that if you let go of them.

http://en.wikipedia.org/wiki/Speed_wobble

Oops! Correct URL now posted - in no way did I mean to imply you are a cretin. Doh!

cheers , loads of info there! thanks! Thinking back now, I leaned back as I placed the eyeware on which may have caused the front end to become lighter creating that underdamped second order system and a positive feedback mechanism effect...I think...or not.

It gave me the jeebies anyway because it started quite quickly and got worse fast...

And no, I'm not from Crete...

[Ixion]

Um, just a thought, but maybe try holding onto the handlebars with at least one hand at all times?

I find it works for me

[stunz]

Um, just a thought, but maybe try holding onto the handlebars with at least one hand at all times?

I find it works for me

now theres a thought...mmm

[Highlander]

Til reading this I never thought of donning sunnies while traveling. I always stopped then put them on (or off).

[quickbuck]

Til reading this I never thought of donning sunnies while traveling. I always stopped then put them on (or off).

Yep, me too. I would be prone to sticking them into my eyes.

As for speed wobbles, it could be a case of worn swing arm bushes.

The fact that the front is wobbling can be a symptom of something going on in the rear.

I remember telling a mate about this as we were adjusting his chain. We got so deep in the conversation that both of us forgot to tighten his real axle.
As he came up to the first intersection he recognised the symptoms I was talking about straight away.

[stunz]

As for speed wobbles, it could be a case of worn swing arm bushes.

Possibly new ones would make a difference as I replaced all them fuggers about 3 months ago as part of a service. I reckon it was just a bad mix of speed, road surface and abnormal weight distribution. Just a quirk of physics I reckon.

[Madmax]

2004 ZX10Rs do this for no reason at all
(Kind of why there so much fun)