Road Cycling - Bike Manufacturer Frame Sizes

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watch
03-02-01, 11:30 PM
So some folks measure frame size from the
center of the crank to the center of the top
tube along the axis of the seat tube? (Is that
correct and defined as 'ctc'?
And some people measure frame size
along the same axis from crank center
to the top of the seat tube? (Is that
correct?)
So does anybody know how Trek,
Cannondale, and Bianchi define their
frame sizes?
Thank you very much in advance.
slo

Xavier
03-07-01, 02:54 PM
Great question and a question that many think they know but they do not.

Frames need to be sold by top tube lenght.

All manufacturers measure all their frames different. Either center to center or center to top of clamp or center to top of seat tube.

Just because 2 frames are sold to you as the same as they are the same "size" they are not the same. Mistake many shops make as many do not know the sport.

You can have for example 2 frames measuring say 55cm (c-c) but both will have a different lenght top tube. Most buyers are unaware of this until they ride the bike and find out it is either too long or too short. I run across this every day through conversations and it angers me.

Please ask questions and listen. Many people think they know and block themselves out.

Here is a great link for some more clarity - <http://www.bullteksports.com/catalog/frame_sizing.htm>