Bonneville Fork Leg Lengths Difference

Discussion in 'Technical Help' started by pseudonym, Feb 2, 2026.

  1. pseudonym

    pseudonym New Member
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    Dec 22, 2025
    18
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    Glasgow
    #1 pseudonym, Feb 2, 2026
    Last edited: Feb 2, 2026
    I am plodding my way through the bike , 2008 T100 EFI, today I decided to change the fork oil, everything went to plan, no problems, then with both forks on the bike I looked at it on the table and thought the right leg was sitting lower down than the left. I looked at the caps protruding from the top yoke, they were the same height above the yoke, so I took both forks off and measured them from top of black sections to bottom, see pics below.

    The right fork tube is longer than the left by about, not precisely, 1cm - 1/2", , all the attachment points, for mudguard braces etc. are the same distance on both legs, it's just the lengths are slightly different. The forks have casting marks 908MD R on the right fork and 908MD L on the left, and as far as I know are original.

    Can anyone please tell me if the fork legs should be different lengths?, if so I wonder why?
    Thanks .

    left
    left leg2.jpg

    Right
    rightleg.jpg

    Both
    both legs.jpg
     
  2. TRIPLE X

    TRIPLE X Senior Member

    Sep 1, 2021
    688
    243
    Norfolk
    Doesn't the bottom of one fork leg clamp around the wheel spindle but the other one doesn't? Length from top to wheel spindle should obviously be equal on both legs.
     
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  3. pseudonym

    pseudonym New Member
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    Dec 22, 2025
    18
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    Glasgow

    Do you know, you are most likely correct, I never even thought about that, I was so focused on the obvious difference in length it didn't even cross my mind to look at that, I measured the distances for all the attachments but didn't do the spindle distance.
    Just shows you that sometimes you can't see what's staring you in the face and another set of eyes spots it right away.

    Thank you.
     
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  4. pseudonym

    pseudonym New Member
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    Dec 22, 2025
    18
    3
    Glasgow
    Triple X, exactly as you said!

    Just been into garage there to fit the legs and measured up and sure enough right down to the bottom of the spindle hole all attachment points are the same. I don't know how many times in 50 years I have changed fork oil and just got on and did it without thinking, maybe the differing lengths just caught my eye and I overthought it, "couldn't see the wood for the trees", as they say.
    What a muppet!!!!!!

    Anyway, thanks again!
     
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  5. Iceman

    Iceman Crème de la Crème

    Apr 19, 2020
    2,991
    1,000
    Lancashire
    The fork legs are exactly as they should be length-wise.
     
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