Measurments from tip of saddle to centre of the BB

nicensleazy
nicensleazy Posts: 2,310
edited July 2010 in Workshop
Any one know the formula of working out the best measurment for the rider from the tip of the saddle to the centre of the BB. Cheers

Comments

  • redddraggon
    redddraggon Posts: 10,862
    It's called Trial and Error.
    I like bikes...

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  • topdude
    topdude Posts: 1,557
    I can't imagine any relevance between the tip of a saddle and the BB :?
    It must depend on the individual saddle and how you sit on it.
    There is the plumb-line from knee to pedal spindle method which takes into account the above.
    I think it is really down to "trial and error" go for a ride with an allen key in your pocket and try the saddle through it's range of fore / aft movement to find the most comfy position.
    Then of course there is the height to worry about :wink:
    He is not the messiah, he is a very naughty boy !!
  • neeb
    neeb Posts: 4,467
    I'm trying to remember how they worked it out when I had a bike fit 2 or 3 years ago, but can't... All I know is that they moved me forward and it helped quite a lot.

    I would imagine that if there are any formulas then femur length must have a lot to do with it. If your saddle height is worked out from the angle of your knee at the bottom of the pedal stroke, then for two people with the same saddle height, I would assume that the one with the largest femur / lower leg ratio would have the greatest saddle setback.

    As said above, distance from tip of saddle to BB will be saddle specific - I was given this measurement when I had my bike fit, but it was assuming I was using a Specialized Toupe. The critical measurement will be distance from wherever it is on the saddle your sitbones are placed, to the BB. But it's a lot easier to measure from tip of saddle, so if you are always using the same saddle it is good to have it converted into this form.

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