Retrobike Forum Index

It is currently Sun Nov 01, 2020 2:58 am

* Login   * Register * Search  * FAQ



Post new topic Reply to topic  [ 14 posts ]  Go to page 1, 2  Next
Author Message
PostPosted: Sun Sep 27, 2020 3:38 pm 
Retro Guru
User avatar

Joined: Mon Jun 19, 2017 7:01 pm
Posts: 1181
Location: N.E.England
A previous repair weld on my ti frame has cracked. DS chainstay to BB. Impatient question as my local welder is closed today - can a Ti weld be repaired a 2nd time usually?

Cheers


Top
 Profile  
 
 Post subject: Re:
PostPosted: Sun Sep 27, 2020 4:24 pm 
Retro Guru

Joined: Fri May 15, 2015 4:57 pm
Posts: 2258
why would you want to?


Top
 Profile  
 
PostPosted: Sun Sep 27, 2020 4:35 pm 
Retro Guru
User avatar

Joined: Mon Jun 19, 2017 7:01 pm
Posts: 1181
Location: N.E.England
edited - response not required


Top
 Profile  
 
PostPosted: Sun Sep 27, 2020 5:23 pm 
Retro Guru
User avatar

Joined: Mon Jun 19, 2017 7:01 pm
Posts: 1181
Location: N.E.England
An ex bike builder I know reckons yes, if it can be cleaned of all contaminants. I'll be sticking the BB in the ultrasonic cleaner as a pre-clean to whatever the local ti welder does (if they think it's a goer)


Top
 Profile  
 
 Post subject: Re:
PostPosted: Sun Sep 27, 2020 9:44 pm 
Retro Guru

Joined: Tue Aug 21, 2018 3:43 pm
Posts: 911
Location: Cambridgeshire - flatlands (the horror, the horror)
It’s worth reading a bit about ti welding. It is fickle stuff, and some owners of very well know US brands know a thing or two about ti cracks. Or five. I have only had good experience - Litespeed-made 1990 ti Team Marin frame, 2014 Stanton Slackline 26-er. Having looked at this issue after a friend’s Titanium Red developed a chainstay crack, I got a few insights from builders and research. The main thing for you is not only the failure of the original repair, but the site of the original failure. For joint failure, the cause can be poor mitre-ing of the joint and/or contamination of the weld during the welding process. And Ti welding has changed a lot over the past two decades, so if your is a Vit T, then quite a lot of procedures have improved. Contamination during the welding process is a cause of a lot of Ti failures - the metal formation during welding, and the bonding of the weld to the old metal surface must not include any oxidation at all, hence the need to weld in an inert environment. Yours is at the chainstay-BB joint? If the original weld failed through contamination - and that is very likely - then the first repair would have been unlikely to endure. That then places a challenge for the repair, which necessitates removing all the old weld, and then welding with a totally perfect uncontaminated second procedure, with the tube mitred exactly to mate with the BB surface. That’s pretty demanding, and there are only a couple of builders in the UK who can work to those kinds of standards with Ti. You sure can re-weld ti, but not if there are elements of the old, brittle weld in evidence. If the failure has occurred somewhere along the length of the tube - unusual, but that’s what happened to my friend’s Ti Red - then the repair is relatively simple. Vernon Barker are recommended, also Enigma. But it won’t be cheap I am afraid. I hope this helps.


Top
 Profile  
 
PostPosted: Mon Sep 28, 2020 3:16 pm 
Retro Guru
User avatar

Joined: Mon Jun 19, 2017 7:01 pm
Posts: 1181
Location: N.E.England
Thanks for that feedback - much appreciated. Aye - it's a bugger. It's a T2 which I believe were more prone to cracking.

I guess what you suggest would mean removal of chainstay & jigging to hold in place during reweld? Something a regular welding shop isn't going to be tooled up for. If viable I'm planning to take it to a local place - a big concern who do fabrication for offshore but still take on small jobs like bikes. They did a really neat job of a seat tube split but I can see this a different level of difficulty.


Top
 Profile  
 
PostPosted: Mon Sep 28, 2020 7:29 pm 
Retro Guru

Joined: Tue Sep 27, 2005 8:52 pm
Posts: 868
Location: South West
As mentioned enigma cycles can undertake this more advanced titanium frame repair work. I discussed via email a cracked seatube cluster (previously repaired and failed - my bad for riding too hard it I guess). Cost of cutting out and fitting a new tube was in the £100s of pounds , with the very good advice of ‘depends how much you love the frame‘... in the end I sold the frame (on here) as a ‘time line’ / collectors piece...


Top
 Profile  
 
PostPosted: Mon Sep 28, 2020 9:36 pm 
Retro Guru
User avatar

Joined: Mon Jun 19, 2017 7:01 pm
Posts: 1181
Location: N.E.England
Thanks. My pockets are a lot shallower now so it could end up being parted out if the local place can't adequately get into the join to renew the weld cleanly. Shame as it's a lovely, nippy ride. I've only been using it on predominantly lane rides.


Top
 Profile  
 
 Post subject: Re:
PostPosted: Mon Sep 28, 2020 10:35 pm 
Gold Trader
Gold Trader
User avatar

Joined: Fri Jan 23, 2009 2:30 pm
Posts: 16800
Location: Surrey
As above really. Enigma will do a first rate job but at first rate cost. I have a frame with a cracked chain stay, enigma would remove and replace. Vernon barker would just weld the crack leaving an agricultural finish with very little guarantee it would stay welded. They were only charging £50 vs several hundred.


Top
 Profile  
 
PostPosted: Tue Sep 29, 2020 4:12 am 
Retro Guru

Joined: Mon Jul 20, 2009 6:27 pm
Posts: 918
I've had two titanium welding jobs done. Enigma never got back to me on the first so Vernon had both of them. I agree his work is not pretty, but it held well enough. Second time around, I had to do my own fettling to get the seat post back in (about 5 minutes with a file). He's also quick, I had about a week turnaround in both cases.

I've still got one titanium mountain bike in the collection, but it rarely gets ridden. I feel like I've slightly fallen out with the material as the result of two cracks.


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 14 posts ]  Go to page 1, 2  Next

All times are UTC [ DST ]


Who is online

Users browsing this forum: Majestic-12 [Bot] and 44 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  

About Us

Follow Retrobike

Other cool stuff

All content © 2005-2015 Retrobike unless otherwise stated.
Cookies Policy.
bikedeals - the best bike deals in one place
FatCOGS - Fat Chance Owner's Group

Powered by phpBB® Forum Software © phpBB Group