Originally Posted by
jeirvine
Nice bikes. What is the biggest 700c tire one can fit on a ~1982 720? One popped up on the local CL and my brother is looking for a commuter/tourer that can take like a 36 or bigger.
It's somewhat variable as others have pointed out. It can handle a 32c or 1 and 1/4 and after that it may get dicey. Also all but the 1982 (which used calipers) was designed around a 27 inch wheel so cantilever adjustment can be a problem compounded by the narrow posts. So going to 700c on one of the post '82 720s will help you use a little fatter tire but you'll have to deal with the cantilever issues.
Originally Posted by
The Golden Boy
They had to fade it to black and hope no one noticed the difference.
I'm very much an enthusiast about Trek's bikes of the 1980s, I didn't realize how well appointed the 1987 520 was.
Trek's 531 framed touring bikes of the 70s were the TX 700 and the 710. In 1982 they introduced the 720 as the high end touring bike. Over the years between 1982-1985 it evolved into what most people recognize as one of the ultimate touring bikes. It seems that in 1986 the bottom dropped out of the touring market- presumably gone to ATBs. Trek dropped the 720 (and 620) and the 520 was a distinctly "not exactly tour-y" type bike. I thought Trek stayed that route until after 1988, but a few forum members have recently acquired 1987 520s that really surprised me with the chainstay length and the geometry and components that were on par with other makes of touring bikes.
Trek also made touring bikes in the 70s made of Ishiwata tubing (the 510).