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  • Ribble's answer to the Pompino

    The 0 rake looks weird..

    Draw a line on the photo: the rake isn't 0 and the forks are backwards.

    Chart says "fork trail 40mm".

    I threw the numbers in their geo chart into a CAD program. Since head and seat angles are the same, wheelbase, chainstay length, bb drop and horizontal TT length are enough to prove their chart is wrong:

    Same for all sizes:
    CS 415mm
    BB drop 49mm

    (max 40mm tyre listed, so using 700mm dia tyre for trail calcs)

    Small
    Wheelbase 1015
    HTT 575
    =>Rake 41.35
    =>Trail 67.0

    Medium
    Wheelbase 1029
    HTT 595
    =>Rake 35.62
    => Trail 73

    Large
    Wheelbase 1060
    HTT 625
    =>Rake 36.58
    => Trail 72

    Assuming the fork rake is 40mm, calculated wheelbase would be
    Small 1013.59
    Medium 1033.59
    Large 1063.59

    If by "fork trail" they mean "horizontal distance between the hub axis and the steering axis" (which isn't how forks are specced because this varies according to the headangle) then 40mm there gives wheelbases
    Small 1011.65
    Medium 1031.65
    Large 1061.65

    Their numbers seem inconsistently wrong, so it's hard to work out which values are calculated and rounded and which were selected.

    Their diagram shows stack and reach, but the chart doesn't specify them and because the head and seat angles are the same, you can't work them out without knowing the A-C length of the fork and the assumed stack height of the external headset lower assembly.

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