Originally Posted by
Cratecruncher
It's an Italian frame with Columbus tube but I just now checked anyway to be sure. It's 28.6+ including paint. The most frustrating part is knowing if I'd just left it alone with all the 50 years of accumulated crud I wouldn't have this problem. It didn't start slipping until I did the detail treatment. It seems you and others are suggesting tapes and rubber of various sources. I'll do some experimenting and keep this thread updated.
The 3M "grip tape" or traction tape has a cloth core and is very stable, basically I think the sandpaper finish on the tape is what is going to keep things in place.