Originally Posted by
gilmo789
Thanks for the responses guys.
I haven't any idea how old the frame set is, but some of the components are quite old, like a fluted shimano 600 crank and an old campag headset, but the decal looks like a more modern vinyl type and has purple lettering which makes me think its not that old. Anyay it's clearly been used a lot and the chainstays haven't cracked yet. there's no shainstay bridge either. It doen't seem like a very old bike. I think it was probably a custom job.
Another weird thing is that the rear wheel sits slightly off centre but the spacing is 126; so the rear triangle has been bent at some point.
89-94 style decal
ww.reynoldstechnology.biz/wp-content/uploads/2015/10/decal_history.pdf
I'd be surprised if anyone built frames around 27" wheels after the 70's but it is possible. Any dent in a heat treated tube creates the possibility of cracking where the dent is located. I've seen this happen on small dents in seat and down tubes. All I can say is that I would never try to dent a heat treated chain stay if it was my own bike. If somebody paid me and damn any consequences, I would try to increase the ovalization using 2 pieces of flat wood that are shaped a bit like the stay so there is no edge that might indent the stay. I would not use any of the shapes commonly used today to try and increase clearance that create an indent like a crater. Wherever there is a crease greatly increases the chance of cracking.
Many frames are built out of true. This is especially the case that one rear stay is just a bit longer than the other. This is one of the hardest things to get right when building a frame. That mismatched distance is amplified out by the rim/tire by a factor of almost 3. In other words if one seat stay is 1mm longer than the other, than the tire will sit over almost 3mm from center. Of course it is also possible that the dropouts are not equidistance from the frame's centerline. This can be especially true for small time builders that don't have good fixturing or alignment tables.