a question from long ago answered

a few months ago I asked what might cause the bars to wobble when you let go
of them.

I can tell youthe answer now. A bent swing arm.

I bought a Fazer, which had the problem mentioned. One wet day I braked
slightly hard at 20mph in a straight line and found myself on the floor.
The bike was written off. The most expensive repair identified was a bent
swing arm. There's no way I bent it in the spill, but it would explain the
wobble and also falling off in a straight line at 20 mph.

So, if the bars wobble when you let go, there's one thing to check, at
least.

John

 

" "

 

Is this the same guy with a Fazer that Statto and I followed from the
Black Horse at Hulland Ward through the back lanes to Matlock Bath, in
which case your swingarm wasn't bent enough to stop you riding very
swiftly and in perfect control on that occasion.

 

John:
No, the last time we met was at the ESOM three years ago, and at that time I
had a balck SV650. Before that it was gliding in Dunstable. I only had the
Fazer for 6 months or so...

As for the swing arm, no it wasn't bad enough to stop me going swiftly,
although I always had the feeling that a Fazer should handle better than it
did....

John

 

They're shit bikes.

 

It depends how you aligned the rear wheel.

Did you trust the chain adjuster markings or check with a straight-edge or
even by sighting down the rims?

Few bikes have accurate adjuster markings, even if their s/arms aren't bent,
and this can result in head shakes and other strange effects as your
"single-track vehicle" becomes an off-set track vehicle.

 

On Sat, 01 Mar 2008 22:41:53 GMT in uk.rec.motorcycles, jsp says:

[Fazer]

When mine went through a stage of doing that it was a fucked front
tyre. Started cracking along the side where the tread was cut. I got a
refund from Bridgestone.

 

My Guzzi *used* to do this when the front tyre had less than a couple
of thousand miles on it and was just a couple of pounds over pressure,
especially if the back tyre was at the lower end of its recommended
pressure range. I didn't need to let go of the bars to experience it,
either.

It hasn't done it since the last front tyre change. Purely out of
curiosity, I tried playing with the pressures to see if I could
reproduce the effect but to no avail, so something's definitely
changed. Possibly Pirelli have changed the tyre design, or maybe the
suspension has sagged with age or it's a result of me dicking with it.

The one time I rode a bike with a twisted swingarm, to the extent that
the wheels were visibly out of line when sighted from the front, it
simply tended to roll left when the bars were released; there weren't
any wobbles.

Similarly, a misaligned rear wheel on another bike simply caused it to
want to roll in one direction when the bars were released.