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Bike Veers to the left

Discussion in 'Technical and Troubleshooting Torque' at netrider.net.au started by Mallaby, Feb 1, 2009.

  1. Howdy all, I'm after some suggestions as to what could be causing this particular problem on my yamaha yzf600r thundercat:



    Bike rides fine when i have hold of the handlebars, but if I sit up straight, inline with the bike and drop my hands to my side, the bike veers slowly to the left. The longer I leave it the more it turns. And from time to time the bike feels like it's fighting me just a little when conering by counter steering.

    I do my rear wheel alignment more often that the pope goes to church so I know that's not it.

    could it be a front wheel alignment if there is such a thing?
    Some worn bushes somewhere?

    any help would be greatly appreciated

    cheers
     
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  2. Most roads are high in the middle for drainage....
     
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  3. thats what I figured so I tried it in a carpark, left lean. mega high crest, left lean, almost dead flat road, left lean. wrong side of the road, left lean. Even on a right slanted road you still feel it wants to go left.

    either the bike has a problem somewhere or i weigh more on my left side than my right
     
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  4. You cant be centred on the seat.
    How stuffed is the rear tyre?
     
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  5. I'd take a stab and say your tyres might be causing the problem.
     
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  6. Could be any number of problems:
    - saggy front spring
    - misaligned axle (either)
    - forks not even
    - incorrectly adjusted rear wheel (don't trust the notches)

    String-line the bike and you will have a better idea
     
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  7. ok so tyres are brand spankers, problem was there before and after new set went on.

    I have tried many seat possies but to no avail.

    rear wheel is always aligned with stringline and calipers.

    I would love to know how to do the alignment on the front so I could eliminate the front axle. and how to check fork eveness. Any takers?

    cheers
     
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  8. Was it previously owned by a member of the Communist Party?
     
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  9. Badoom ching!
     
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  10. Check headstem bearings yet?
     
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  11. ??

    You should be stringlining the front wheel to the back.
     
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  12. yeah thats how it is done
     
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  13. nah but i prob should.

    but would that really hold the wheel off center?
     
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  14. Have you checked whether or not the forks are 'tweaked' to the left? undo the top triple clamps a bit and see if the fork legs move slightly into their normal position, then do the bolts up again.
     
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  15. I did a variation of this once then measured the swing arm markers for accuracy. No need to do it each time now. :wink:
     
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  16. Shut up son or I'll nail your other foot to the ground.
     
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  17. OK some measurements for diagnosis:

    Fork height above top t.clamp: equal
    Distance between t.clamps (figured I may as well) : equal

    HOWEVER...

    Left fork is sagged by 5mm at the same preload and while vertical on a paddock stand

    could this be it?
    what are my options for replacement springs? (yes money is an object)
    Where on the frame do I measure the swing arm height?
     
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  18. Noice!
     
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  19. You don't. The back will loose damping as a first sign of needing a rebuild.
     
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