General Cycling Discussion - how to measure frame size?

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View Full Version : how to measure frame size?


g3ck0
08-11-04, 09:51 PM
when ppl say their frame size is 59cm -- is that measured from the ground to the top horizontal tube? what if that tube is slanted?

thanks :)


g3ck0
08-11-04, 11:52 PM
anyone?

TechJD
08-12-04, 01:12 AM
messure from the center of the bottom bracket ( center of the pedal arm (known as a crank) ) to the top of the seattub


KevinF
08-12-04, 05:43 AM
There really isn't much of a standard in measuring frame sizes and it makes it hard to compare frame sizes between manufacturers. The three methods I'm aware of are:
1) Center to center. Center of the bottom bracket (i.e., the crank-arm axle) to the center of the top tube
2) Center to top. Center of the bottom bracket to the top of the seat tupe
3) Center to top, part 2. Center of the bottom bracket to the top of the seatpost collar

The differences between method #1 and #3 can obviously vary by up to 2 or 3 centimeters, which is why you'll hear sometimes "if you ride a 58cm brand XXX, you'll need a 60cm brand XXX"

bac
08-12-04, 08:47 AM
The differences between method #1 and #3 can obviously vary by up to 2 or 3 centimeters, which is why you'll hear sometimes "if you ride a 58cm brand XXX, you'll need a 60cm brand XXX"

If you have a sloping top-tube, your numbers will be WAY off relative to a conventional top tube. Some sort of a standard would be nice! :D

jeff williams
08-12-04, 10:17 AM
Well, with mtb, really the standover is whatever you can do.

It doesn't matter if I stand over 16-18 inch. The tope tube is your 'reach' and dictates how much control you will have over steering. I shop toptubes, a 15 inch seattube, I raise my seat, a 20 inch toptube requires a new longer headset.

>jef.