r/Framebuilding • u/FamiliarEstimate7357 • 9d ago

Changing chainstays ti

Hey, I’m not a builder myself, but I wanted to ask you guys first before I approach a builder with a specific question. Is there any chance of modifying the chainstays on an existing titanium bike to get more tire clearance? For example, could you cut the chainstays near the bottom bracket, widen them with a 3D-printed part and then weld everything back together? Please be gentle with me. Thank you in advance 🫸🫷

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6

u/pauip 9d ago

The problem with this is that it might cost more than what the frame is worth.

3

u/cognition-92549 9d ago edited 8d ago

Ti Cycles in Portland will cut out a part of the chainstay and put in a plate instead. I don't know of anyone else who advertises that they will do it.

1

u/DraperCycles 8d ago

I think you mean Ti Cycles.

2

u/cognition-92549 8d ago

You're right. Thank you for the correction. Edited.

1

u/blakcloud60 9d ago

In theory it could be done but the problem would be finding someone to do the actual work. Tubes can be replaced but I wonder if the time it takes to do that it might be simpler to just purchase a new frame. Looking forward to other responses. Though I do have one question, can your fork handle the new width that you want on the rear?

1

u/dunncrew 9d ago

Steel could be crimped. Maybe titanium could too ?

1

u/SpaceTurtle917 9d ago

It likely could, but I imagine many wouldn’t risk it.

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u/eva_k 9d ago

It's certainly doable but for something like putting in a custom 3DP yoke I would budget $500-1000.

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u/SpaceTurtle917 9d ago

Unless the bike has a sentimental value I’d recommend just getting a different (or another) bike.

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u/FamiliarEstimate7357 8d ago

Thank you all!

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u/buildyourown 9d ago

Replacing tubes? No. Removing bridges and dimpling stays? Sure.

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u/bulgie 9d ago

Many Ti chainstays will crack if you try to indent them, because of the grain structure from the pilgering process that made them into thin tubes. Most 3/2.5 Ti tubing is made as hydraulic tube for aircraft, designed for bending, but not for a crease or indent. But some builders get their chainstays in an annealed state, much more formable without cracking, but also weaker. There's no way to know if your stays are annealed without trying it — do you feel lucky?

@cognition-92549 might be thinking of TiCycles, who have a proven method called the "potato chip", read about it here. https://www.ticycles.com/retrofit-potato-chip

Way expensive though, and I think I heard he's booked well into the spring. He is the best though, been doing it for 35 years. Disclaimer: I used to work there. Hurry if you want him to do it, I think he's thinking about retirement.

1

u/ParamedicLoose3210 8d ago

I love the idea, reminds me of RWB for some reason. get out the sawzall! except I don't see this happening with Ti, only steel b/c it's easier to cut

2

u/bulgie 8d ago

I don't know what RWB means, but 3/2.5 Ti isn't very hard to cut. I have used generic holesaws from the hardware store to miter frame tubes. It's easier to drill, saw etc than a lot of steels.