Making alterations to a frame

[Westerlywind]

Hello, there is an old steel Raleigh Elkhorn frame whose welds failed at the joint where the seat stays meet the seat tube. I can supply photos. It wasn't a catastrophic failure but the one side had rusted (at the braze point) and failed then took the other side out due to stress doubling on it. I still have the frame and may consider "customizing" it a bit, then making it roadworthy once again. It seems that the "tacking" method (where framebuilders join the seat stays to the seat tube) isn't all that strong. I've seen other frames fail similarly. I thought about fabricating an additional strut that would attach the seat stays at a slightly lower point down the back of the bike, then attach that to the seat tube too. Input on this proposed modification/improvement from experienced modifiers and builders welcome!

[sokyroadie]

Wind Chime since it is windy

Is there a sentimental attraction to the frame? I would think if it rusted that much it is toast.

[arimajol]

Old steel bikes are plentiful. Unless you really gotta have this one, just find another. Saves the effort of trying to fix it, and the risk that your fix might fail.

[unterhausen]

The millions of un-failed side tacked seat stays out there argue fairly effectively against your assertion that there is something wrong with that method. It takes a moderately skilled craftsman to pull it off. And sometimes there is not enough overlap of the stay with the seat tube and it breaks. OTOH, you don't have to look at too many factory fastback seat stay attachments before you find one that's cracked. And that can be a pain to fix.

Back when I was an undergrad, I used to reattach seat stays and brake bridges for beer money. It's easy work. If you modify the design it's going to cost a lot more. Should be $300 or more before paint unless the person is giving away their labor.

[mhespenheide]

Agreed. Unless you've got a personal attachment to this specific frame, or you're compelled by the idea of the repair process, you're far better off scrapping this one and finding another vintage frame. (And I say that as someone who doesn't like modern throwaway culture) The secondhand market is awash with reasonable replacements that will be less than the cost of the paint [i]or[i] the repair individually, much less the combination of both.

[charliedid]

Originally Posted by Westerlywind

Hello, there is an old steel Raleigh Elkhorn frame whose welds failed at the joint where the seat stays meet the seat tube. I can supply photos. It wasn't a catastrophic failure but the one side had rusted (at the braze point) and failed then took the other side out due to stress doubling on it. I still have the frame and may consider "customizing" it a bit, then making it roadworthy once again. It seems that the "tacking" method (where framebuilders join the seat stays to the seat tube) isn't all that strong. I've seen other frames fail similarly. I thought about fabricating an additional strut that would attach the seat stays at a slightly lower point down the back of the bike, then attach that to the seat tube too. Input on this proposed modification/improvement from experienced modifiers and builders welcome!

Try it, you might like it.

[paredown]

Picture of the damage would help. Does if have a seatpost lug or does it use a clamp?

I was wondering if the rust damage is bad (and there's no top lug), if you could sleeve externally, and rebraze the stays in the original location? (I agree with those who have said there is nothing inherently wrong with the original attachment method--and the failure could well have been a faulty original braze that failed to form a good bond and/or left an opening for water to penetrate...)

[David Kirk]

Originally Posted by Westerlywind

Hello, there is an old steel Raleigh Elkhorn frame whose welds failed at the joint where the seat stays meet the seat tube. I can supply photos. It wasn't a catastrophic failure but the one side had rusted (at the braze point) and failed then took the other side out due to stress doubling on it. I still have the frame and may consider "customizing" it a bit, then making it roadworthy once again. It seems that the "tacking" method (where framebuilders join the seat stays to the seat tube) isn't all that strong. I've seen other frames fail similarly. I thought about fabricating an additional strut that would attach the seat stays at a slightly lower point down the back of the bike, then attach that to the seat tube too. Input on this proposed modification/improvement from experienced modifiers and builders welcome!

So...it sounds like the s-stays are currently mounted to the seat tube where the top tube and seat tube meet...is that right?

And you are thinking of having the s-stays removed and having new ones installed so that they meet the seat tube part way down.

Do I have that right?

dave

[unterhausen]

Originally Posted by David Kirk

Do I have that right?
dave

It's pretty clear he wants to just add some kind of tube to reinforce the joint. Like a gusset tube builders sometimes put on mountain bikes between the top tube and seat tube.

Pictures would help, we're just guessing at this point.

[weisan]

Give it your best shot and report back.

[bart998]

Sounds like a good cleaning and re-brazing is all that is needed... maybe build-up a little extra bronze to make sure they "stay" this time. Easy, peasy.

[Westerlywind]

Photos of the subject frame joint. You know, up here it is difficult to find a big guys mountain bike frame. Anything halfway decent, that is. Stateside - man - you guys have got some serious choice down there. I can (and do) find them here with some effort. I pretty much have to - I haven't had a car for 17 years. I thought I could perhaps resurrect this Elkhorn. The two joints just *click* back into place. For the photo they were forced apart.

p.s. I could send a link to some higher resolution photos. I'd like to thank all who have opined in this thread thus far!

[Westerlywind]

Originally Posted by unterhausen

It's pretty clear he wants to just add some kind of tube to reinforce the joint. Like a gusset tube builders sometimes put on mountain bikes between the top tube and seat tube.

Pictures would help, we're just guessing at this point.

Indeed, some tube gussets from underneath each seat stay to the seat tube was the idea. The ends of the tubes would be contoured to match the mating surfaces.