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what do you think is the best way to measure a frame size(5 posts)

what do you think is the best way to measure a frame sizeCORONADO FLYER
Mar 7, 2003 10:52 AM
lets here it. what measurment sizing is beter.

1. bb center to center of top tube. 2. bb center to top of top tube. 3. bb center to top of seat tube.

there are so many manufacturers using all three types of measurnments. i wish all manufactueres would just choose one. so why do they use three different ones with their frame sizes?
There is another one..Dave Hickey
Mar 7, 2003 10:56 AM
A lot of compact frames are measured with a "virtual" seat tube an top tube.
c-c or c-tFez
Mar 7, 2003 11:18 AM
Center to center would appear to be the most comparable, but I guess slim vs. fat tubes could distort that measurement.

Center to top seems to address put the frames on equal footing for the purposes of standover. Of course BB height and tire size also affect standover.

Center to top of seat collar seems like a worthless measurement, except for Trek. Trek OCLVs seem to have a "lower" top tube (AKA more standover) than other frames, so the seat collar measurement seems to put it on equal footing with competitors. A common mistake when sizing Treks is to think you need a larger frame size because the standover is so low. Then people wonder why the top tube is long on a frame that is too big.

Compact sizing is all about virtual top tubes, since the actual seat tube size is usually irrelevant.

I guess there is no perfect system. Its most important to get all the measurements - top tube, head tube, seat tube, standover (on nonsloping), fork rake, bb height, and seat and head angles. And a few more I left out.
don't care which one, but wish there was a standard method (nm)laffeaux
Mar 7, 2003 11:37 AM
don't care which one, but wish there was a standard method (nm)CORONADO FLYER
Mar 8, 2003 12:08 AM
I DO TO. SO MANY MANUFACTURERS WITH DIFFERENT SIZING. YES CENTER OF BB TO CENTER OF TOP TUBE IS BEST. ANOTHER PROBLEMS IS SOME CYLIST GET CONFUSED AND THEN THINK 62CM IS THEIR SIZE AND THINK A CENTER TO CENTER 58CM IS TOO SMALL. I THINK MORE EDUCATION IS NEEDED FOR BOTH MANUFACURERS AND NOVICE CYCLIST.