Ti repairs

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PH
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Ti repairs

Post by PH »

My pride and joy ti frame has a crack :?
Anyone any experience or recommendations on a repairer? Or advice on if it's worthwhile? Mainly if such repairs are reliable. The crack starts at the weld on the underside of the top tube and head tube. I'd take a photo but I can't bear to look at it again just yet...
Could have been worse, discovered it while doing some routine maintenance rather than while riding...
pete75
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Joined: 24 Jul 2007, 2:37pm

Re: Ti repairs

Post by pete75 »

Vernon Barker cycles repair titanium . Based at Dronfield just outside Chesterfield so not too far from you. http://www.vernonbarkercycles.co.uk/repairs_frames.html

They'd be able to advise if repairs are feasible.
'Give me my bike, a bit of sunshine - and a stop-off for a lunchtime pint - and I'm a happy man.' - Reg Baker
pq
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Re: Ti repairs

Post by pq »

Vernon repaired a Ti frame of mine. His work looks a mess and isn't totally accurate, but I've been using the frame ever since with no problems.
One link to your website is enough. G
PH
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Re: Ti repairs

Post by PH »

Thanks both, Dronfield isn't that far from me, I'll take it in for them to have a look. I've lost a little faith in this frame. so not sure it'll ever be my long distance tourer again, I might have it repaired and demote it to single speed commuter and buy a replacement, except I don't have room for another bike...
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cycleruk
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Re: Ti repairs

Post by cycleruk »

Some Ti frames have a lifetime guarantee. So if it's a well-known make it might worth checking out.
You'll never know if you don't try it.
NewHorizon
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Location: The Marches

Re: Ti repairs

Post by NewHorizon »

Enigma, although reference to alterations and repairs has dropped off their newly revamped website.
Reilly Cycleworks.
pq
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Re: Ti repairs

Post by pq »

I spoke to Enigma (6 years ago) about fixing mine and their response was rather odd. They said they'd do it, but that it wouldn't be a long term fix.
One link to your website is enough. G
Valbrona
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Re: Ti repairs

Post by Valbrona »

People expect some kind of magic repair job. But to properly repair any frame with a cracked tube is to replace the tube.
I should coco.
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Si
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Re: Ti repairs

Post by Si »

I knew someone who cracked a litespeed.....he sent it back to them and they did it for him. It might be worth trying the original maker.
NewHorizon
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Location: The Marches

Re: Ti repairs

Post by NewHorizon »

Si wrote:I knew someone who cracked a litespeed.....he sent it back to them and they did it for him. It might be worth trying the original maker.


It would be interesting to know who the original maker is. Given that most frames are built in China, Russia or parts of the Far East, it's unlikely that the original 'maker' would be able to effect a repair, even assuming they were a) still trading and b) remotely interested. Not that this applies to all Ti frame builders of course.
scottg
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Location: Highland Heights Kentucky,, USA

Re: Ti repairs

Post by scottg »

A friend cracked a chain stay on his Lynskey.
Lynskey replaced both stays with a stouter tube.

Lynskey does build their own frames.
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Deutsche Luftschiffahrts-AG
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PH
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Re: Ti repairs

Post by PH »

cycleruk wrote:Some Ti frames have a lifetime guarantee. So if it's a well-known make it might worth checking out.

No returns in this case, made to my spec in China by XACD, a touch under £450 in 2010 so not the best value ever but not something I'll lose sleep over either. The process of design research and specification was a lot of fun in itself and I learnt a lot from it. There wasn't anything OTP that met my criteria available at the time, though there's a bit more choice now.
I had an accident on the bike back in March, snapped handlebars and the sideways force was enough to wreck a wheel and twist the steel forks. No signs of damage to the frame then, but I couldn't be sure that didn't contribute to this crack between top and head tubes.
Anyway - new frame ordered, I will at some point see if this one can be economically repaired, if so it'll go single speed and be the poshest pub bike in the rack!
Brucey
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Re: Ti repairs

Post by Brucey »

FWIW the stresses on the weld are comprised of service stresses superimposed upon any residual stresses. Immediately after welding, parts of some weldments have residual stresses that are at yield magnitude. If the weldments are heavily restrained, or welding technique is poor, some very nasty residual stresses and stress concentrations are possible.

Thus the recommendation for many fabrications is that they are subjected to a stress relief heat treatment after welding. This alters the microstructure of the weldment and lowers the residual stresses, but it is expensive to do in Ti fabrications. This is very rarely done on Ti bike frames, so you are usually left with the results of the welder's efforts.

At its worst ( barring almighty cock-ups like contamination and poor shielding) you might have a lack of root fusion (horrible stress concentration) and a local residual stress field caused by poor weld placement.

At its best you might have a two-pass weld process with good root bead penetration, careful weld placement and procedure so that the worst kind of residual stresses are avoided.

Probably you had the first one and not the second one. Any repair weld in a location like that will be subject to the restraint of that location (bad) and in addition it may be nearly impossible to clean the parts to the standard required for high integrity welding. Even so Ti fabrications are weld-repaired all the time; it is just that in this case whilst a basic repair is feasible, it may not last, and the cost of doing a proper job (with all the knobs bells and whistles) probably exceeds that of a new frame.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
De Sisti
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Re: Ti repairs

Post by De Sisti »

PH wrote:No returns in this case, made to my spec in China by XACD, a touch under £450 in 2010 so not the best value ever but not something I'll lose sleep over either.

Anyway - new frame ordered, I will at some point see if this one can be economically repaired, if so it'll go single speed and be the poshest pub bike in the rack!


I bought 3 frames from them (around the same time as you did. Didn't get the spec correct on two of them). I sold one to a
friend (who's still using it as a summer bike), I've got one and the other developed a crack at the bottom of the seat tube
near the bottom bracket shell. I decided that as that frame didn't cost too much (iro £350) it wasn't worth repairing, so it
ended up in the council recycling depot.

By the way PH, what was the replacement you went for?
PH
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Re: Ti repairs

Post by PH »

De Sisti wrote:By the way PH, what was the replacement you went for?

I've a steel is real Thorn Mercury on the way, though it's complicated by needing some alterations to the Rohloff hub. If it had been available a decade ago, I would probably have had that instead of the XACD, geometry wise it's very similar. But as I said, the experience of ordering from XACD was interesting in itself. Ride wise I'm unconvinced ti offers much over good steel (I've had this cheapie and a less cheap Linskey) though it's been nice to not worry about scratching paint! I would have considered an OTP ti Rohloff frame if I'd found one that I liked, the Van Nicholas Amazon comes close, but the geometry isn't ideal for me which was the decider, I'm also not keen on the cable run, integrated headset and type of EBB. The Mercury is the dearest frame I've ever bought, I could have gone custom for the same money, but there didn't seem much point as it would have been close to identical.
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