



Bike shop wants to heat and reshape my bent alloy Topstone rear triangle. Is this OK on aluminum?
UPDATE 1: The mechanic called and said he managed to correct it, using hot water to warm the alloy and then cold-setting it by hand (no torch). Rear spacing is now about 137mm instead of the correct 142mm, but he says it's fine to ride and the bike is ready for pickup.
I'll pick it up tomorrow, curious to see... but honestly I'm not risking my neck on a 5mm-under, bent alloy rear end just to save face on a 2k EUR bike 😄 Best case it becomes an indoor trainer frame. For actual riding I think I need a new gravel bike or frame, so I'll keep pushing through the dealers and Cannondale crash-replacement.
I suppose hot water can't get near the temp that ruins the heat treatment, or can it?. But 137mm still means the frame's being sprung 5mm every time the wheel goes in?
Thanks for all the input, especially whoever suggested the indoor trainer idea. That's probably where this frame ends up...
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Bought a 2026 Cannondale Topstone (aluminium) in Barcelona last month. The shop assembled it and packed it into my EVOC bag for my flight home to Turkey. The shop in Barcelona didn't fit a rear dropout spacer/protector in place of the wheel. It arrived with the rear triangle bent, dropouts no longer coplanar, thru-axle won't pass through both sides, wheel won't seat.
I took it to a local shop here in Turkey who is experienced in Cannondale and they measured the dropout misalignment and confirmed it's out of spec.
(Side note for context: the shop that packed it in Spain is refusing responsibility, I'm chasing the airline claim and Cannondale crash replacement separately. Not what I'm asking about here.)
What I'm asking about: the bike shop in Turkey says he wants to fully disassemble the bike and heat the frame to reshape and correct the alignment. Is this a good idea?
If straightening is my genuine last resort (frame is scrap otherwise), is cold alignment with proper frame tools meaningfully safer than heating? Or is any realignment of an alloy rear triangle a bad bet?
Realistically, is a rear triangle that's been bent, then realigned, ever safe for hard/technical riding, or only good for gentle/town use afterward?
Anything I'm missing?
Appreciate your help.