CYCLINGFORUM.COM - Where Cyclists Talk Tech --- Return To Home

 

    Register FAQ'sSearchProfileLog In / Log Out

 

****

cyclingforum.com ****

HOMECLUBS | SPONSORS | FEATURESPHOTO GALLERYTTF DONORS | SHOP FOR GEAR

Return to CyclingForum Home Page CYCLING TECH TALK FORUM
          View posts since last visit

Is this filet brazeable repairable??
 

Author Thread Post new topic Reply to topic
Sparky
Joined: 08 Dec 2003
Posts: 17730
Location: Portland, OR

4/10/20 4:01 PM

Is this filet brazeable repairable??

The gap/openness of the crack concerns me the front triangle may be askew as well... But the frame with the original fork shows no evidence of that...

Perhaps just poor frame alignment window pushing technique when built?

 Reply to topic     Send e-mail

Brian Nystrom
Joined: 26 Jan 2004
Posts: 4626
Location: Nashua, NH

4/10/20 7:13 PM

What is the frame? the BB shell looks pretty low-end, so is it worth the cost to repair it? I also wonder about the effectiveness of filet brazing a BB shell that's apparently not very strong.

 Reply to topic    

Sparky
Joined: 08 Dec 2003
Posts: 17730
Location: Portland, OR

4/10/20 8:32 PM

Cost? No I mean me fillet brazing it. It is sold anyway.

It was a raleigh-track-fork-headset.

 Reply to topic     Send e-mail

dddd
Joined: 11 Jan 2004
Posts: 3299
Location: NorCal

4/11/20 10:37 AM

That area often gets too much heat/time during brazing, reducing the metal's fatigue resistance.

The weak spot has been found and the stress removed from the location for now, except at the ends of the crack, which are now at the peak of stress and fatigue.

The ends of the crack could be drilled out and the area built up with fillet, but the surrounding steel will now have endured yet more heating/time that further diminishes it's quality.

It takes a skilled brazer to do a solid braze joint without overheating the metal, applying the heat effectively while working quickly.

 Reply to topic    

Sparky
Joined: 08 Dec 2003
Posts: 17730
Location: Portland, OR

4/11/20 3:22 PM

Yeah, my fear would have been getting it all too hot and the CS braze breaking flow. It is gone though...

I was oddly attracted to it for $60.00.

 Reply to topic     Send e-mail

dddd
Joined: 11 Jan 2004
Posts: 3299
Location: NorCal

4/12/20 10:48 AM

Back in the earlier days of Ebay when fees were lower, I pulled a few damaged frames from the shop's bin and listed them (as auctions), all with a starting price of $88.

They all sold @ $88 each.

No broken bottom brackets but likely tube replacement candidates, good name-brand frames like Colnago, etc. though none were old enough to be valuable classics.

I could see someone using that Raleigh for it's dropouts perhaps(?).
No way though at $60.
Craig Calfee could fix it by building up a carbon exoskeleton around the whole bb shell, so there's that!

 Reply to topic    

Sparky
Joined: 08 Dec 2003
Posts: 17730
Location: Portland, OR

4/12/20 11:45 AM

It had bars stem, seatpost and saddle. Sushi money the way I see it.

 Reply to topic     Send e-mail

KerryIrons
Joined: 12 Jan 2004
Posts: 3057
Location: Midland, MI

4/12/20 1:41 PM

Repair

Easy to repair. Remove BB shell, braze in a new one. Worth doing? Questionable. When you filet braze a frame, the tubes have to be well-mitered for a very close fit. This frame definitely does NOT fill that bill.

Then there's old "wrap it in fiberglass and epoxy" which is the low-tech equivalent of having Calfee do something.

 Reply to topic    

Anthony Smith
Joined: 12 Jan 2004
Posts: 846
Location: Ohio

5/12/20 9:40 AM

Easy Repair

Warm the bottom bracket shell with a torch, remove the downtube first, then the chainstays. Once it is off, dremel the part stuck to the seat tube on two opposite sides, gently warm it and remove it.

Now the fun part, clean and flux the downtube, seattube, and the stays, clean and flux the inside of the new bottom bracket shell fittings., insert first the downtube, then the seattube, finally spring back the rear triangle and insert the chainstays. Align everything and pin it with small nails. Now heat the new shell and sweat it back together with brass. (Don't exceed 350*F on the tubes.) Clean and paint. Maybe 2 hours of work at the outside.

 Reply to topic    


Return to CyclingForum Home Page CYCLING TECH TALK FORUM
           View New Threads Since My Last Visit VIEW THREADS SINCE MY LAST VISIT
           Start a New Thread

 Display posts from previous:   


  
Last Thread | Next Thread  >  

  
  

 


If you enjoy this site, please consider pledging your support

cyclingforum.com - where cyclists talk tech
Cycling TTF Rides Throughout The World

Cyclingforum is powered by SYNCRONICITY.NET in Denver, Colorado -

Powered by phpBB: Copyright 2006 phpBB Group | Custom phpCF Template by Syncronicity