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Road Bike Sizing

fadsarmyfadsarmy Posts: 12
edited June 2015 in Road beginners
Hello everyone,

I have a problem with sizing of a road bike I want to buy. I've never had this issue before. The size guide for this bike is a bit strange. My inside leg 31" comes under medium but my height 5' 7" comes under small.

Small: height 5′ 7″ - 5′ 10 inside leg 28″ - 30″
Medium: height 5′ 10″ - 6′ 1″ inside leg 30″ - 33″

Do you have any advice please?


  • martino53martino53 Posts: 29
    I'm sure there's many who can give a more techy answer than mine, it would seem you have long legs and a short upper body. So I would concentrate on virtual top tube length fitting your body, otherwise you'll be to steched out. A test ride may be the better option in the end.
    good luck.
  • fadsarmyfadsarmy Posts: 12
    If I go for small, will I struggle with the pedals?
  • keef66keef66 Posts: 13,123
    If you're between sizes like this always go for the smaller frame. You can if necessary fit a longer stem, raise the saddle and even fit a layback seatpost.

    If you get a frame that's too large there's very little you can do to make it fit.

    I'm 5'6" with a 31" inside leg and I'd be going for the small frame. Do you know how long the top tube is?
  • dj58dj58 Posts: 2,185
    Are you buying the bike from a shop or from an internet seller? Can you sit on both of them to see which size fits you better. As mentioned above if between sizes the usual advice is to opt for the smaller frame and adjust the fit via the seatpost/saddle height and stem/handlebar reach.
  • lpretro1lpretro1 Posts: 237
    Buy from a shop that does a proper bike fit?
  • simon_mastersonsimon_masterson Posts: 2,740
    Search Google, use a sizing system. The one that appears in Greg LeMond's 'Complete Book of Bicycling' (which is excellent, by the way) is really good. There are other systems that can help you to estimate what top tube length you want based on the length of your torso.

    A good bike shop will be able to help you to the right size of course, it's not hard; though they make a fortune out of silly people that think they have to pay for something they can and should do themselves.
  • DKayDKay Posts: 1,652
    I'm only 5'4'' but have a 29.75'' inside leg measurement. So long legs, but a short torso. I ride XS frames which generally means 48cm - 50cm with a top tube of around 520mm.

    Generally speaking, I think size S frames would suit you better. But it does slightly depend on the model of bike you're looking at. Riding a slightly too-large bike feels terrible, compared to one which fits you well.
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