Instability At Higher Speeds

[afterburn]

I am experiencing some problems with stability at speeds of and in excess of 90mph. The bike starts kinda weaving left to right instead of following a straight line. Putting the screen down helps some, but not all. I think this is tire related, as the rear tire is been worn pretty flat by the previous owner and is severly cupped. Front looks ok.

Can any give me any comments on this and/or confirm this is likely to be a tire issue?

 

[teerex51]

* What tires do you have, Avons?

* Have you checked your steering head nut? It might be loose.

* Do you have a non-OEM top case?

Stef

 

[afterburn]

- It runs Pirelli Diablo's.

- No, but it doesn't feel like it's loose. I will check though. It's a very distinct feeling when it is while riding and braking, and I haven't noticed anything weird in that area.

- No top case at all. Hate the damn things.

 

[markjenn]

The most common cause of weaves is too-tight steering head bearings or some kind of aero instability, often caused by having a top case. Do you have anything non-stock on the bike that would effect its aero profile?

- Mark

 

[Bike Effects]

- It runs Pirelli Diablo's.- No, but it doesn't feel like it's loose. I will check though. It's a very distinct feeling when it is while riding and braking, and I haven't noticed anything weird in that area.

- No top case at all. Hate the damn things.

I have never owned a bike that didn't have to have the steering stems bearings tightened up after a short time. I bought my FJR used with 5800 miles on it, and the previous owner had already had this done.

 

[afterburn]

Well, mine had 50.000km on it when I bought it, and just had full service. So I'd say, that was taken care of. Then again, assumptions are the mother of all fuckups, so I will check.

 

[Warchild]

The most common cause of weaves is too-tight steering head bearings or some kind of aero instability, often caused by having a top case.

Absolutely correct.

What about a top box, afterburn, do ya have one installed?

 

[afterburn]

Nope, don't have one and will never have one either. Hate them darn things. They look shite and put the weight up high and behind the rear axle, which will seriously mess up handling.

 

[eaglemike]

Not that he really needs any second - but I will second what WC said - rear tire worn a bunch (especially worn flat) causes weird handling problems, in my experience. I just helped a friend change from a totally worn out (flat) tire to a take-off I had laying around with 50% left. He said it totally transformed the bike. He'd been chasing steering bearing adjustments, etc.

All the best,

Mike

 

[motorgod]

* What tires do you have, Avons?
* Have you checked your steering head nut? It might be loose.

* Do you have a non-OEM top case?

Stef

Is there a problem with Avons?

 

[Vulcan]

Change tires......Don't cheap out on trying to get the last mile out of a set of tires.

 

[NoCage]

Is there a problem with Avons?

MG... Not really... the tread pattern may cause a very slight weave, but at low speeds. Mine did when I first got them, but after a couple of thousand miles, that's either gone, or I just don't notice it anymore. The tires are awesome... much better grip, especially in the wet stuff. This comparison is based on my Bridgestone B020 OEM's.

 

[velvet fog]

I noticed weaving at about 135. No top box, new BT020's (less than 300 miles), but I did have stuffed dry bag strapped to by garauld rack.