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braze on downtube shifter lever bosses on aluminum frame?

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braze on downtube shifter lever bosses on aluminum frame?

Old 08-02-23, 07:38 PM
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BikePower
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braze on downtube shifter lever bosses on aluminum frame?

I would like to modify an aluminum frame to have downtube shifter bosses for some Shimano frictionless shifter levers. How can I accomplish this? Also, the down tube is not round. Any help is appreciated. Thanks.
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Old 08-02-23, 07:41 PM
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Steve B.
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Something like this

https://problemsolversbike.com/produ...-shifter-mount

Just get a tube diameter and see what fits. I did a Google of “Bolt on downtube shifter mounts”
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Old 08-02-23, 08:00 PM
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Originally Posted by Steve B.
Something like this

https://problemsolversbike.com/produ...-shifter-mount

Just get a tube diameter and see what fits. I did a Google of “Bolt on downtube shifter mounts”
The thing is the tube is not round. Do you suppose some kind of epoxy would be strong enough to hold the steel bosses on the aluminum frame? Do they make aluminum bosses?
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Old 08-03-23, 07:44 AM
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I have read of using a heavy duty "hose clamp" that has had the shift bosses brazed to it as an adaptor. This could conform to a non round tube easily.

Another possibility is to use a through the tube shaft that has shift boss shapes that attach (thread on) to it's ends. Much like what Cannondale used for years.

However I do hope the shifters that wtll be used do have some friction to them, otherwise the lever will just return to the position the der's spring pulls it to. An indexed shifter has a huge amount of friction, just located at specific spots about the lever's spool. Andy (who as a kid wondered why anyone would want a date with two pits in it. One pit is enough, "pitted dates" to me meant more were added, not the one removed)
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Old 08-03-23, 09:00 AM
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Originally Posted by Andrew R Stewart
I have read of using a heavy duty "hose clamp" that has had the shift bosses brazed to it as an adaptor. This could conform to a non round tube easily.

Another possibility is to use a through the tube shaft that has shift boss shapes that attach (thread on) to it's ends. Much like what Cannondale used for years.

However I do hope the shifters that wtll be used do have some friction to them, otherwise the lever will just return to the position the der's spring pulls it to. An indexed shifter has a huge amount of friction, just located at specific spots about the lever's spool. Andy (who as a kid wondered why anyone would want a date with two pits in it. One pit is enough, "pitted dates" to me meant more were added, not the one removed)
It makes total sense though and explains why pitted dates are more expensive. Think of the machines and hoppers with date pits that are required to install additional pits in dates.
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Old 08-03-23, 12:11 PM
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Originally Posted by BikePower
It makes total sense though and explains why pitted dates are more expensive. Think of the machines and hoppers with date pits that are required to install additional pits in dates.
The New Yorker humor writer Calvin Trillin once wrote a very funny article on regional differences in chili recipes. He noted that one restaurant in Cincinnati, which offered chili in a bewildering array of variations, including "five-way" and "six-way" varieties, had a prominently displayed sign reading "CHILI WITHOUT BEANS - 50 CENTS EXTRA." Trillin said he wondered how much the professional bean extractors would have been paid so that the restaurant broke even on each bowl.
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Old 08-03-23, 02:42 PM
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That chili is always disappointing, but it's apparently the best you can do in Cincinnati. So I always go there when I'm nearby.
With beans though, they can put the ones they took out of the "without" in my dish.
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Old 08-10-23, 02:43 AM
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You could braze them on with TIG aluminium bronze. You could also TIG weld them but there's a good chance that using aluminium bronze would affect any heat treatment less. There are also kind of aluminium solder type things that you see people doing at very low temps with a blowtorch (just butane or something). Not very strong but might be good enough for shifter bosses.
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