Why do I have to lean over to keep my bike rolling straight?

Started by stopintime, September 28, 2009, 12:44:54 PM

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stopintime

When I take my hands off the bars, either rolling in a high gear or with the fast idle lever on, I have to lean over to keep it rolling straight. I tried it in the opposite lane as well to be where the road has a left falling/facing degree - same, but not as much. I have to pull left and/or push right to follow a normal straight line, not much but anyway.

The bike has not been down, it has SSS.

Only thing I can think of is that the fork upgrade was done with the forks off, but the forks are even height at the top tripple.

What do you think?
252,000 km/seventeen years - loving it

ducpainter

I'm told the 1098/848 does it because of the swingarm and battery/electronics all being on the left side.

Have you moved anything to further bias the weight to one side on your bike?

I know you have less exhaust than a stock bike.
"Once you accept that a child on the autistic spectrum experiences the world in
 a completely different way than you, you will be open to understand how that
 perspective
    is even more amazing than yours."
    To realize the value of nine  months:
    Ask a mother who gave birth to a stillborn.
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somegirl

When I used to ride MrI's S4R, I always felt a slight pull to the right (he never noticed).

At one point prior to the sale I took it to a frame expert to have the bike professionally measured and evaluated.

After he took lots of measurements he asked me if it pulled to the right (I was impressed).
Turns out that the fork position was slightly off from one of the lowsides, it wasn't visually evident but he could detect it.

Anyway, he just had to make a small adjustment and the pull went away.

So you might want to re-check your forks, loosen them up a bit then re-tighten.
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Christian

+1 what somegirl said. Especially if you've had the forks off the bike, there's a good chance that you're just slightly off on the alignment. They can be tricky to get right.

stopintime

I have to lean to the left, so the swingarm is probably not it. Exhaust and battery is on the right hand, so....

It's too bad I didn't check (or notice) any of this before the fork was off. If the fork legs are out of allignment - is that a matter of trying and testing? The suspension shop will probably do it for free, if it's that easy.
252,000 km/seventeen years - loving it

ducpainter

Quote from: stopintime on September 28, 2009, 01:42:01 PM
I have to lean to the left, so the swingarm is probably not it. Exhaust and battery is on the right hand, so....

It's too bad I didn't check (or notice) any of this before the fork was off. If the fork legs are out of allignment - is that a matter of trying and testing? The suspension shop will probably do it for free, if it's that easy.
Did you push down on the forks before tightening the axle?
"Once you accept that a child on the autistic spectrum experiences the world in
 a completely different way than you, you will be open to understand how that
 perspective
    is even more amazing than yours."
    To realize the value of nine  months:
    Ask a mother who gave birth to a stillborn.
"Don't piss off old people The older we get, the less 'Life in Prison' is a deterrent."



stopintime

Quote from: ducpainter on September 28, 2009, 02:07:26 PM
Did you push down on the forks before tightening the axle?

The shop did the work, so I don't know. Should they? Why? Brakes on or off?
252,000 km/seventeen years - loving it

ducpainter

Quote from: stopintime on September 28, 2009, 02:15:47 PM
The shop did the work, so I don't know. Should they? Why? Brakes on or off?
It aligns the axle and legs, so I'm told.

Basically just loosen the axle and pinch bolts. Push down on the bars several times to compress the forks then re-tighten. I don't think it matters if the brakes are applied.

(Det justerer aksel og ben, så jeg sa.

Utgangspunktet bare løsne aksel og klemme bolter. Trykk ned pÃ¥ barer flere ganger for Ã¥ komprimere gaflene sÃ¥ re-stram. Jeg tror ikke det spiller noen rolle hvis bremsene brukes)  ;D
"Once you accept that a child on the autistic spectrum experiences the world in
 a completely different way than you, you will be open to understand how that
 perspective
    is even more amazing than yours."
    To realize the value of nine  months:
    Ask a mother who gave birth to a stillborn.
"Don't piss off old people The older we get, the less 'Life in Prison' is a deterrent."



stopintime

252,000 km/seventeen years - loving it

herm

This map is upside down, the plan is written in crayon, and the weather forecast is from 2011.

ducpainter

"Once you accept that a child on the autistic spectrum experiences the world in
 a completely different way than you, you will be open to understand how that
 perspective
    is even more amazing than yours."
    To realize the value of nine  months:
    Ask a mother who gave birth to a stillborn.
"Don't piss off old people The older we get, the less 'Life in Prison' is a deterrent."



dlearl476

If the "loosen the axle/pinch bolt" bit doesn't work, this article is an excellent step-by-step of diagnosing and repairing crooked forks. It's written for BMW forks, but most of it translates directly.

http://w6rec.com/duane/bmw/fork/contents.html

IdZer0

I had the same problem a while ago. It went away when I replaced the front tyre. Don't know if it was the axle/forks alignment or maybe asymmetrical wearing of the front tyre (track  I went to is mostly right-handers)
2007 Monster 695, DP ECU, Low mount Alu Termignonis
replaced by 2011 848 EVO

herm

This map is upside down, the plan is written in crayon, and the weather forecast is from 2011.