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Old 02-11-08, 09:51 AM   #1
Skewer
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Small Crack at Brake Bridge and Right Seat Stay

I have an old, 1982, 531 steel tubing bike that I have set up for loaded touring. When shipping it to a tour a number of years ago, UPS managed to bend in the right rear seat stay such that the brake bridge was also bent in, knocking the rear brake out of alignment and making the rear brake unusable. The rear wheel, however, still seemed to slide in and sit in the dropouts/frame in a perfectly aligned position. I then relegated the bike to a trainer for some years until yesterday morning, when at such time I was able to straighten the rear seat stays by eyeball, using a lug wrench to leverage the stays back in to position. After repeatedly going out to the garage and looking at my fix it job from different angles during the rest of the day, which really looked pretty darn straight most times I looked at it, by late last night I could not leave well enough alone, and decided to give the rear seat stays one last tweak with a bigger crowbar.

Of course that final tweak with the big bar was one too many and I started to separate the brake bridge from the right rear stay with a very small, hairline crack where the brake bridge attaches to the right, seat stay. (I would give you a picture but my camera isn't available right now). So here are my questions: Assuming that the structural integrity of the seat stays themselves is good, and assuming for a moment that the alignment of the frame is good enough for my loaded touring application (remember, the rear wheel looks like it sits in there in a perfectly aligned position), how important is that brake bridge to the structural integrity of the frame? And when choosing from potential, further fix it alternatives going from the easiest to the most complex, what do you think I need to do? JB weld? Braze on by professional non bike guy? Weld by professional non bike guy? Is there a specific type of welding I should choose? Or is this a serious enough problem that I need to remove all the components from the frame and ship it off to a frame builder/frame repair guy to professionally reattach the brake bridge and check frame alignment?

If I get it brazed or welded locally, can this be done in a manner where it only ruins the paint on the seat stays for a few inches, such that I could just rattle can the repaired area rather than getting the entire bike repainted? This is not a, beautiful, vintage Colnago that demands a perfect finish, but rather a tough, utilitarian, well traveled, bike for loaded touring, where a few imperfections and battle scars only add to its wizened character imo.

Thank you for any insights or suggestions.

Last edited by Skewer; 02-11-08 at 10:31 AM.
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Old 02-11-08, 10:10 AM   #2
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If it were my frame...I'd have it welded.

Although the frame may be overbuilt for the use it will see, losing the strength of that brake bridge can transfer loads to a different part of the frame that was never stressed before, leading to a break. I have seen aluminum frames that had more than one break: the first crack and the second where the stresses were transferred to, broken clean through. Fortunately for you, steel is the most repairable of materials and any good welder (bicycle experience or no) that understands the material should be able to weld it. Find someone you trust and ask their advice on which method fits the application.
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Old 02-11-08, 10:30 AM   #3
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Welding is probably not a viable, much less cost effective, answer. Because the brake bridge was brazed in the first place (1982 you say, right?) there is brass in the joint and would have to be completely cleaned out prior to a weld. You would have to have the joint re-brazed. Most likely the paint damage would indeed be isolated to the area around the brake bridge and could easily be covered up with a little spray. Have you looked around on fleabay or CL for another frame perhaps? You may be able to simply find a similar frame from the same period for the same or a little more than the repair would cost and you wouldn't have anything to worry about in the future.
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Old 02-11-08, 10:41 AM   #4
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If it were my frame...I'd have it welded.

Although the frame may be overbuilt for the use it will see, losing the strength of that brake bridge can transfer loads to a different part of the frame that was never stressed before, leading to a break.
Ok. Good points. Thanks for the advice. Just to clarify, it is my intention to use the bike again on some loaded tours, so it can never really be "overbuilt" imho.
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Old 02-11-08, 11:10 AM   #5
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Welding is probably not a viable, much less cost effective, answer. Because the brake bridge was brazed in the first place (1982 you say, right?) there is brass in the joint and would have to be completely cleaned out prior to a weld. You would have to have the joint re-brazed. Most likely the paint damage would indeed be isolated to the area around the brake bridge and could easily be covered up with a little spray. Have you looked around on fleabay or CL for another frame perhaps? You may be able to simply find a similar frame from the same period for the same or a little more than the repair would cost and you wouldn't have anything to worry about in the future.
Thank you. When you say "welding is probably not viable answer", does that include "brazing" so that you are saying brazing is not a good answer? I am confused as to what is viable and is not viable since there are different types of welding. Would brazing likely be very expensive? Regarding the bike, I perfectly realize that the old frame isn't worth anything to anybody else, but I have it set up very comfortably with gearing, shifters, racks, spare parts and accessories for touring, and the bike is well tested. I was guessing that the simplest, most straightforward solution was just to repair the brake bridge where it attaches to the seat stay in some manner as opposed to having to look for another bike, having to switch the components over and dial in a different bike. As far as worrying, yes I won't be taking the old bike on tour to Cambodia anytime soon, but at the same time, I would have no qualms or worries about taking the old bike back out on more modest tours here locally in the US. And I have four other bikes that will be taking up 90% of my regular riding, so I am not looking to repair this bike with the thought of it lasting for another 10,000 miles as my main ride.

Thank you for your insights.

Last edited by Skewer; 02-11-08 at 12:23 PM.
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Old 02-11-08, 12:25 PM   #6
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Redtires,

Thank you for your answer. I edited my reply to you above to clarify where I still have some confusion regarding welding and brazing, and exactly what you are suggesting is not a viable option. Hopefully you can clarify for me. Thank you!
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