The BSA A7-A10 Forum
Technical (Descriptive Topic Titles - Stay on Topic) => Frame => Topic started by: bakerlonglegs on 29.10. 2018 21:12
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Hi all,
The side stand that came in the box of bits that will eventually form my bike is missing the pin that the spring hooks onto. See pic.
Is that repairable? I'm hesitant about drilling or threading anything into the gap in case it weakens the stand. I have kept an eye on eBay for replacements but I really want to keep the original set up.
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It appears to have been badly brazed. Why not make a new pin and braze or silver solder it in place again. There would be no need to enlarge the existing hole; just clean it. If you can get the job properly hot the braze or solder will flow into the hole and around the pin.
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Yup, no need to drill or re tap, just sand blast/clean it up, and bronze a new tab for spring. Absolutely no change to strength of stand arm then and good as new.
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Thanks very much for the replies, that’s great to hear I can reuse it. I’ve never done any brazing before - time to do a bit of googling to see how it’s done and what kit I need.
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Thanks very much for the replies, that’s great to hear I can reuse it. I’ve never done any brazing before - time to do a bit of googling to see how it’s done and what kit I need.
You must have gone to a posh school. In my school we did woodwork, metalwork and technical drawing. All very useful to me. Mind you, we didn't do foreign languages, which would also have been useful.
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I would look it all over really well for any possible cracks. It could be my junky phone, but I think I see something on both sides of the hole *ex* *????*
Lee
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I would look it all over really well for any possible cracks. It could be my junky phone, but I think I see something on both sides of the hole *ex* *????*
Lee
Looking at this zoomed screen grab, you may be right
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Don't see any cracks there, just a bit rough where the brazing has torn away. Pin can't have been a very good fit to do that. Have to say silver solder is probably the best method of fixing a new pin, as it tends to flow better than brazing. That said, silver solder rods cost around £12 each nowadays and you'll need oxy acetylene to heat it, as it needs to be a dull red (and the small flame helps to draw the filler around). In your situation, unless you've a mate with the gear I'd seriously consider tapping the hole and screwing a pin in - assuming of course the hole is an appropriate undersize for a nominal bolt dia.
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G'day bll.
Yes they look like cracks to me as well. If they are you'll need to braze a fair area around the pin.
Cgeers
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"...you'll need oxy acetylene to heat it, as it needs to be a dull red (and the small flame helps to draw the filler around)."
'Mapp' gas as used by plumbers is great for brazing and silver soldering, cheap and easy to get (unlike oxy acetylene).
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"...you'll need oxy acetylene to heat it, as it needs to be a dull red (and the small flame helps to draw the filler around)."
'Mapp' gas as used by plumbers is great for brazing and silver soldering, cheap and easy to get (unlike oxy acetylene).
I have a Butane plumbers torch. Is Mapp gas hotter?
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I have a feeling that 'MAPP' is a gas 'cocktail' possibly including some butane, but I'm not sure, no expert.
It is certainly hot enough for brazing and silver soldering, no problem heating steel to red hot.
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I would look it all over really well for any possible cracks. It could be my junky phone, but I think I see something on both sides of the hole *ex* *????*
Lee
Lee,
You sir (and your junky phone) are spot on. I hadn't noticed it myself, but then my close-up eyesight is shocking these days. Thank you very much for pointing that out. I've tried to take a closer pic.
I think I'll have to look at some sort of new solution now. I can't risk that cracking on the bike and the whole lot clanking to the ground. I might get a bit emotional...... *pull hair out*
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It's flipping lucky that crack was spotted!
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It's flipping lucky that crack was spotted!
You’re not kidding!
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I have a feeling that 'MAPP' is a gas 'cocktail' possibly including some butane, but I'm not sure, no expert.
It is certainly hot enough for brazing and silver soldering, no problem heating steel to red hot.
Perhaps it's Propane or contains it. I know that Propane burns hotter than Butane.
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I looked this up a while ago, but just so sI get it 'right'...;
https://en.wikipedia.org/wiki/MAPP_gas (https://en.wikipedia.org/wiki/MAPP_gas)
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If Muskrat is right and those are cracks, that would account for the pin failure, as the pin would no longer be a good fit in the hole. Unless the leg is welded before a new pin is brazed / silver soldered in, it will fail again. Too risky in my view, especially as new legs are readily available.
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If Muskrat is right and those are cracks, that would account for the pin failure, as the pin would no longer be a good fit in the hole. Unless the leg is welded before a new pin is brazed / silver soldered in, it will fail again. Too risky in my view, especially as new legs are readily available.
Sounds like a good diagnosis.
Unfortunately new legs for ‘53 and earlier plunger frame bikes aren’t that easy to find. I’ve got a search on eBay for them but no one sells them new.