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took the bike out the other day to find this:
Hence my other post about something to replace it with.
It's a Pace RC129, 853, old school geo (71.5 deg 1 1/8th headtube etc). That folded crack below the sleeve repair I had recently had done has daylight when you remove the seatpost. I've not seen a tube so thin on an MTB for quite a few years. It's a 27.2ID with a 28.6OD (well it is with paint on it). normally they're externally butted to 31.8. Pace do like to do things weirdly. Tig welding the frame, then fillet brazing and smoothing to get smooth lines. then chroming the frame. very odd. anyway..
If I were to repair it, the correct method would be to replace the seat tube in it's entirety. or, possibly re sleeve to below the seat cluster. Both of which will be more than the frame is worth.
If I relegate it to light duties, could the buckle be smoothed and the crack welded, or filled with braze?
otherwise it'll sit in my shed looking shiny, and broken.
Won't that be fine with a seatpost properly inserted? Would only get worse/disconnect if you had the seatpost only inserted to above the bulge.
don't know. it happened with the seatpost fully inserted (it's a 400mm seatpost), so maybe if I'm not abusing it?
I assumed that the bit below the repair sleeve, as it's very very thin, was flexing under normal use.
its been repaired a few times now, so maybe one other time isn't going to hurt...
I've done a very ugly split sleeve repair on my first home made frame that was the same 28.6 tube reamed for 27.2 post. Silver soldered in place so at a push can be done diy / minimal cost with a plumbing MAPP gas torch.
Still holding up after 4 years as my commuter bike (12 years old in total) . The internal crack occasionally squeaks and needs a squirt of lube :-).
I'm not aware that anyone makes a 27.2 bore tube that is butted 31.8 od (that is crazy thick). Even sleeved it is only 30mm od. Everything I make now is sleeved to below the junction and minimal seat tube above the top tube / seat stays.
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that's a fine bit of wiggly reinforcement that.
I may have been talking out of my ass re: 31.8. 30.0 does seem far more reasonable, it's what the sleeve repair is on that!
I had the same problem as you - easily chopped off / sleeved crack up top then a trickier one in the junction.
A patch might buy you a few years for minimal cost.
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