Framebuilders - chainstay bridge is compromised, is this a problem?

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well biked
06-14-06, 04:04 PM
I bought a Centurion Pro Tour recently, an '83 model I believe. A real, full-on touring bike. The bike's condition overall is fair, but I'm hoping to get it back on the road. But before I get too far into the project, I need to determine if I've got a serious problem with the chainstay bridge. The frame is of Tange Champion #2, and it's completely chromed beneath the paint. The frame tubing has some rust on the inside of the tubes in places, but it doesn't appear to have hurt anything. The previous owner installed a kickstand, and I believe this is how the chainstay bridge was damaged. It was dented very noticeably, caved in on top, near the center. I've checked the frame's alignment, and also the rear dropout spacing, and everything seems fine, it apparently hasn't been cold set, as the spacing is 126mm. I probably should have just let it be, but that caved in spot was going to bug me, so I decided to try and take the dent out. I was able to get the end of an allen wrench inside the small bolt hole that is in the chainstay bridge (the hole that's there for the installation of fenders), and I slowly began to tap the dent out by tapping the end of the allen wrench with a hammer . If this was dumb, then I'm guilty as charged, but what's done is done. I was encouraged at first, because the dent was coming out, although I was having to hit the allen wrench pretty hard to have any affect on the dent. Eventually I had it looking pretty good. Just a few more strokes with the hammer........and then I noticed a small crack in the top of the bridge. It was small, but jagged, and so I decided to drill the spot where the crack was, reasoning that the crack would be less likely to spread from a clean, round hole than from a jagged crack. So what I have now is a chainstay bridge that's nearly perfectly round again, but with a hole in the top (where I drilled it to get rid of the crack, approx. 1/4" diameter). I also filed the tube to get rid of the high spots where the end of the allen wrench distorted the tube from the bottom side, so I've got significantly thinner material in the chainstay bridge tube on the top side now, near the center of the bridge, and of course this is also where the hole I drilled is. The welds where the bridge attaches to the chainstays look good, apparently unaffected by all this.

So, as I see it, I've got three choices at this point: I can cut my losses now and scrap the whole project, and save the parts from this bike for another frame; I can send the frame away for a repair that will probably cost more than I paid for the whole bike and might exceed the value of the frame, even if it were in near perfect condition; or I can proceed with the project, filling the hole in the chainstay bridge before repainting, and hope that nothing bad comes of this chainstay bridge problem. What do you all think?


Nessism
06-14-06, 08:58 PM
Chainstay bridges don't do squat, don't sweat the dent/hole. Fill it in and go.

Mannydog
06-15-06, 08:50 AM
Chainstay bridges don't do squat, don't sweat the dent/hole. Fill it in and go.

Agreed.


well biked
06-15-06, 09:25 AM
Thanks guys-

rmfnla
07-23-06, 09:10 PM
... and don't forget to toss that stupid kickstand!

MRoth
07-25-06, 11:59 AM
I'd look around to see if there is a framebuilder somewhere near you. I've found that sometimes a small repair like that is quite resonable to have done. I've had a few braze-ons put on and was surprised to find out how cheap it was. If you ask for just the repair and do the paint touch-up yourself it might be pretty cheap. It doesn't hurt to ask the price. And yes, get rid of that kickstand.

well biked
07-29-06, 06:09 PM
I'd look around to see if there is a framebuilder somewhere near you. I've found that sometimes a small repair like that is quite resonable to have done. I've had a few braze-ons put on and was surprised to find out how cheap it was. If you ask for just the repair and do the paint touch-up yourself it might be pretty cheap. It doesn't hurt to ask the price. And yes, get rid of that kickstand.

You know, I ended up doing just that. Even though I'm sure, as others have said, it wouldn't have hurt anything to go ahead with the frame as it was, I did contact a framebuilder and for a very reasonable price he replaced the bridge and even did a great job of touching up the paint where he did the repairs. And while I had the frame in for the repair, I had him add water bottle bosses to the seat tube, which will allow me to carry three water bottle cages. It was worth the peace of mind to have the bridge replaced, for me anyway. And btw, the framebuilder that did the work for me is David at Southwest Frameworks in Dallas. Very nice guy, he treated me right and I couldn't have been happier with the work-

edit: And YES, the kickstand is long gone! :D