Ti welds crack and snap- Mtbr.com
Results 1 to 13 of 13
  1. #1
    mtbr member
    Reputation: gonzo's Avatar
    Join Date
    Feb 2004
    Posts
    458

    Ti welds crack and snap

    I guess it could happen to any Ti weld from any company???
    In one week:
    1- heard a squeak in the head set, thought it was my head set going, turned out to be a crack in the weld -headtube
    2- my seat had a squeak, then snapped off at the weld. Lucky I was just riding in my drive way checking my brakes

    I ride cross country rigid and weight about 165lbs -

    Just wondering if this is normal for all welded TI?
    Name:  crackheadset.JPG
Views: 476
Size:  23.4 KBTi welds crack and snap-dsc04027.jpgTi welds crack and snap-dsc04028.jpgTi welds crack and snap-dsc04029.jpg
    Attached Thumbnails Attached Thumbnails Ti welds crack and snap-crackheadsetoutline.jpg  

    Last edited by gonzo; 06-04-2019 at 07:08 AM.

  2. #2
    Cleavage Of The Tetons
    Reputation: rideit's Avatar
    Join Date
    Jan 2004
    Posts
    5,863
    Cheap, light, strong...pick one?
    "We LOVE cows! They make trails for us.....

    And then we eat them."

    Thrill Bikers Unite!

  3. #3
    Shamisen Appreciator
    Reputation:
    Join Date
    Jan 2004
    Posts
    2,020
    Quote Originally Posted by gonzo View Post
    I guess it could happen to any Ti weld from any company???
    In one week:
    1- heard a squeak in the head set, thought it was my head set going, turned out to be a crack in the weld -headtube
    2- my seat had a squeak, then snapped off at the weld. Lucky I was just riding in my drive way checking my brakes

    I ride cross country rigid and weight about 165lbs -

    Just wondering if this is normal for all welded TI?
    Name:  crackheadset.JPG
Views: 476
Size:  23.4 KBClick image for larger version. 

Name:	DSC04027.JPG 
Views:	74 
Size:	147.1 KB 
ID:	1255041Click image for larger version. 

Name:	DSC04028.JPG 
Views:	87 
Size:	137.9 KB 
ID:	1255039Click image for larger version. 

Name:	DSC04029.JPG 
Views:	88 
Size:	139.3 KB 
ID:	1255037
    I can't see what's going on with that head tube, it would help to see the inside. You can clearly see evidence of bad backpurge on the seat post. It's a scaly mess in there and my guess is that whoever welded it didn't have it positioned correctly or didn't wait long enough. If it was no purge at all, you'd see the scale further into the tube. You can also see evidence of a cold weld on the last photo...on the left hand side there's a clear line that separates the weld bead from the actual tube...in fact you can pretty much see the whole mitered end of the tube...which means that it didn't get a root pass and the filler pass didn't get hot enough for proper penetration. My guess is the welder didn't want to key open the clamp tube by giving it proper heat.
    Sean Chaney :: Owner/Builder :: Vertigo Cycles

  4. #4
    slow
    Reputation: sgltrak's Avatar
    Join Date
    Feb 2005
    Posts
    6,571
    When I took this one to a local builder to be repaired, he mentioned that he has stopped building frames with short head tubes that require "stacking" the top tube and down tube because he has seen several crack at this junction. Apparently this causes a different set of stresses than if the tubes were welded around the entire circumference. He now prefers to build with a taller head tube so that he can get full circumference welds around both the down tube and the top tube at their intersection with the head tube.

    Ti welds crack and snap-img_20180822_151226_771.jpg

  5. #5
    Frame Building Moderator
    Reputation: Walt's Avatar
    Join Date
    Jan 2004
    Posts
    7,489
    Chi-Ti?

    I agree with Sean, this is a purge issue almost certainly, though we can't tell without looking inside the tubes on the failed frame. Seatpost shows obvious contamination.

    Short head tubes are a generally bad idea too, of course.

    -Walt

  6. #6
    Frame Building Moderator
    Reputation: Walt's Avatar
    Join Date
    Jan 2004
    Posts
    7,489
    Quote Originally Posted by sgltrak View Post
    When I took this one to a local builder to be repaired...
    That is not safely repairable, unless by "repair" you mean replacing the entire front end of the bike... did someone actually weld those cracks and give you back the frame? If so, stop riding it right now.

    -Walt

  7. #7
    slow
    Reputation: sgltrak's Avatar
    Join Date
    Feb 2005
    Posts
    6,571
    Quote Originally Posted by Walt View Post
    That is not safely repairable, unless by "repair" you mean replacing the entire front end of the bike... did someone actually weld those cracks and give you back the frame? If so, stop riding it right now.

    -Walt
    He drilled holes at the end of the cracks and then welded. I've got about 1000 trail miles on the bike with no issues since then, but keeping a close eye on it.

    Ti welds crack and snap-img_20180831_172639_708.jpg

  8. #8
    Shamisen Appreciator
    Reputation:
    Join Date
    Jan 2004
    Posts
    2,020
    Quote Originally Posted by sgltrak View Post
    He drilled holes at the end of the cracks and then welded. I've got about 1000 trail miles on the bike with no issues since then, but keeping a close eye on it.

    Click image for larger version. 

Name:	IMG_20180831_172639_708.jpg 
Views:	38 
Size:	87.6 KB 
ID:	1255135
    That's all well and good and I'm glad it hasn't come apart on you but the underlying problem hasn't been addressed. The surface has been patched and that's it. We don't know why it cracked but it's a safe bet that either there's some internal contamination or there was a gap where the TT and DT joined the HT and it wasn't fully welded. Laying down more filler doesn't fix it and it's a matter of time before it cracks again. I wrote a multipage post on MTBR a number of years ago and am not inclined to do it again. If you're interested, maybe search for it and get a little education.
    Sean Chaney :: Owner/Builder :: Vertigo Cycles

  9. #9
    slow
    Reputation: sgltrak's Avatar
    Join Date
    Feb 2005
    Posts
    6,571
    Quote Originally Posted by smudge View Post
    That's all well and good and I'm glad it hasn't come apart on you but the underlying problem hasn't been addressed. The surface has been patched and that's it. We don't know why it cracked but it's a safe bet that either there's some internal contamination or there was a gap where the TT and DT joined the HT and it wasn't fully welded. Laying down more filler doesn't fix it and it's a matter of time before it cracks again. I wrote a multipage post on MTBR a number of years ago and am not inclined to do it again. If you're interested, maybe search for it and get a little education.
    Thank you. I'll look for the post.

  10. #10
    Shamisen Appreciator
    Reputation:
    Join Date
    Jan 2004
    Posts
    2,020
    I did what I said I wasn't going to do and posted here: https://forums.mtbr.com/california-n...l#post14117793 . I'd absolutely welcome any builder discussion.
    Sean Chaney :: Owner/Builder :: Vertigo Cycles

  11. #11
    Frame Building Moderator
    Reputation: Walt's Avatar
    Join Date
    Jan 2004
    Posts
    7,489
    Quote Originally Posted by sgltrak View Post
    He drilled holes at the end of the cracks and then welded. I've got about 1000 trail miles on the bike with no issues since then, but keeping a close eye on it.
    I would have refused to do that repair, personally. Good luck, and yes, keep a very close eye on it.

    -Walt

  12. #12
    Frame Building Moderator
    Reputation: Walt's Avatar
    Join Date
    Jan 2004
    Posts
    7,489
    Wait, you've had this thing repaired, and ridden it a lot since then, and you post a thread now?!?

    I'm curious as to why you decided to post this here today.

    -Walt

  13. #13
    slow
    Reputation: sgltrak's Avatar
    Join Date
    Feb 2005
    Posts
    6,571
    Quote Originally Posted by Walt View Post
    Wait, you've had this thing repaired, and ridden it a lot since then, and you post a thread now?!?

    I'm curious as to why you decided to post this here today.

    -Walt
    I am not the OP. I just jumped in because I saw that the damage to my frame was similar to what the OP posted.

Similar Threads

  1. ti welds/discoloration bad?
    By teamdicky in forum Frame Building
    Replies: 27
    Last Post: 04-09-2012, 02:36 AM
  2. paint crack or frame crack?
    By fujibikeben in forum Frame Building
    Replies: 5
    Last Post: 10-16-2011, 07:53 PM
  3. Frame crack or paint crack?
    By Rad Rider 415 in forum Niner Bikes
    Replies: 1
    Last Post: 05-06-2011, 07:20 AM
  4. welds, welds, whatever... Mooto-x is done
    By beerorkid in forum Frame Building
    Replies: 9
    Last Post: 09-06-2006, 12:29 PM
  5. Tech. content tubing, welds, Ti, Steel
    By vcyclist in forum Frame Building
    Replies: 14
    Last Post: 02-09-2005, 05:09 AM

Members who have read this thread: 1

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

THE SITE

ABOUT MTBR

VISIT US AT

© Copyright 2020 VerticalScope Inc. All rights reserved.