Date: Thu, 30 Jun 2005 21:34:22 EDT From: Carb7008@cs.com To: classicrendezvous@bikelist.org Subject: [CR]753 vs 531
Any clues as to whether a "mystery" frame might be made of 753 vs 531? A local framebuilder (753 certified) said no (seatpost diam, weight, etc). I noticed that 753 seatstays have (mostly?) double tapers. This builder said 531 ss could also be had in double taper. Anyone know or have an 80's 531 frame with double taper seatstays or an 80's 753 frame with single taper seatstays?
Jack Romans Sacramento, CA 1) Weight - the 753 frame (not 753R) will be significantly lighter than an equivalent 531 frameset (about 3/4 of a pound). 2) Seat post diameter - 753 tubing came in Metric diameters only, AFAIK, so the seat posts required were generally 26.8 mm (sometimes 27.0) vs. 27.2 mm for 531. (Athough very heavy-gauge 531 frames sometimes used 26.8 posts, but the weight difference would be even greater for one of those vs. 753) 3) Ductility - you can't cold-set 753 (not sure how you would test this in practical terms, though!). If you're talking 753R, that's different. 753R tubing was Imperial (inch) sized and 753R frames usually take a 27.4 mm post IIRC (Waterford, Riv., Merckx, etc.), and the weight difference (compared to 531) is smaller. The 27.4 post is a dead giveaway, generally. Of the "big two" tubing manufacturers, only KL & Record tubing from Columbus use that diameter also, AFAIK.... Greg "753 all the way" Parker Ann Arbor, Michigan