My gf did a little spring cleaning on her bike today. I thought I'd share with y'all. Enjoy.

You have the tubing listed as 531c. Does it really have the "c" on it? I've read elsewhere that the 531c tubeset came out in the early 80's (1983+/-), meaning a 531 "club" set, with a 531 main triangle and 501 stays (not sure about the fork- although I think it's a 531). This tubeset was around in the 70's? Help me out here.
Nice C&V ride, though.

marqueemoon, where does your gf ride? Does she ever hit the GRT/Interurban? I'd love to see the Mercian in person.

East Hill

531c was the competition tubeset. There was a club sports tubeset (531cs) which may be what you are thinking of. The stays (and forks, steerer and head tube) were made from CrMo and were of the same gauge as 501.

The bike in question does appear to use the more modern Reynolds decal. I'm not positive, but I thought this decal came out about the same time as Reynolds 501 (i.e. 1983). However, Reynolds decals are very fragile and there is always the possibility that this is a replacement.

Thanks, I had never seen this transfer sheet before. So the info I thought I read about 531c was really about 531cs. A few more questions for the experts. My '84 Trek 760, according to Trek brochures, was supposed to be in 531p - is that the 531 Professional? My frame's serial # dates to 1983, but with the changed '84 lugs and paint scheme, but seemingly with the '83 531c tubing - or did builders not use 531p above a particular frame size (ala Columbus with SL/P and the X series tubing) - mine's a 58cm? And one more, in the same article I referenced it had Reynolds 501 as a seamed tubing - is that correct? Thanks again.

It has a 531c sticker on the seat tube like #11 on that guide and 531 shield stickers on the fork blades.
So it sounds like the consensus here is this is a circa '83 frame (if the decal is original). I'm sure sending the serial to Mercian would solve the mystery. We've just been lazy.

East Hill - We're not out on the eastside much. You might see this bike out on Chilly Hilly if the weather looks iffy though. She rode STP on it in 2005, and it also does commuting duty so you might see it out and about. It's pretty hard to miss.

I'll be keeping an eye out for it.

East Hill

Yes 531P was the "professional" tubeset. It was 150g lighter than 531C, so many builders would not use it on larger frames, as thee cyclist would typically be heavier and stronger. Many manufactuers also had a cross-over point where they mixed the tubesets (i.e 531C downtube and chainstays with 531P elsewhere). I'm not sure if trek used this philosphy.

Yes, 501 was seamed. However, by this time seamed tubing had come a long way and there is nothing inferior about it. It was simply a less expensive mehtod to manufacture the tubes.