Calculating stand over from bike geometry

suzyb
suzyb Posts: 3,449
edited April 2012 in Road beginners
Is it possible. I checked out a cube bike today but am not sure what size it was. And I'm trying to see if I can work it out by the stand over height which was about 68cm. Cube's website doesn't give stand over height on the geometry table however. Can it be calculated?
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  • team47b
    team47b Posts: 6,425
    A 50cm Cube (Axial pro wls) is 73cms to the top of the frame at the midpoint of the top tube.

    Doesn't really answer your question though...
    my isetta is a 300cc bike
  • team47b
    team47b Posts: 6,425
    As Cube only do 47cm 50cm 53cm and 56cm womens I would assume based on the 50cm bike sat next to me with the 73cm stand over that you must have been looking at the 47cm.

    Other than that, a protractor, pencil, ruler, you have all the angles and tube lengths, make a scale drawing using the 73cm stand over known measurement of the 50cm frame.
    my isetta is a 300cc bike
  • fosst
    fosst Posts: 45
    I think the answer is no...you can measure wheel radius minus the bottom bracket drop add the seatube to middle of top tube and I'm lost from there...
    But, if you nip out to the garage and measure up a 47cm Axial wls you get standover of 68-69cm. Much easier, hope that helps!
  • MattC59
    MattC59 Posts: 5,408
    I think you're going to spend a long time trying to work this out. To calculate it, you need to know the BB height, seat tube length (C to T) and seat tube angle and a bit of trigonometry you can work it out (sorry, can't remember whether you need cos, sin or tan).

    or...........

    You need the wheel & tyre radius, axle to BB drop, seat tube angle, seat tube length (C to T) and the same bit of trigonometry.

    To be honest it would be easier to ask the dealer / owner of the bike what size it is. I assume that if you could measure the standover height, you could ask the owner ?
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  • suzyb
    suzyb Posts: 3,449
    fosst wrote:
    I think the answer is no...you can measure wheel radius minus the bottom bracket drop add the seatube to middle of top tube and I'm lost from there...
    But, if you nip out to the garage and measure up a 47cm Axial wls you get standover of 68-69cm. Much easier, hope that helps!
    It does indeed. It must have been the 47cm I stood over.
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