Fix for misaligned Braze on????

[Lugger]

Any suggestions for fixing a misaligned braze on? I purchased a frame via the forum and finally completed the assembly 6 months later. Only now, after struggling with adjusting the FD has it been pointed out to me that the braze on is out of alignment with the seat tube. Its a 5 degree difference at most (see first image with added lines to highlight variance).
http://forums.thepaceline.net/attachment.php?attachmentid=1697880670&stc=1&d=1399688425

This causes the cage to be misaligned which leaves very little tolerance for FD adjustments. (look at bottom of cage in next image).
http://forums.thepaceline.net/attachment.php?attachmentid=1697880671&stc=1&d=1399688670

My LBS tech said that you can't really bend a braze on since they are cast and the metal is brittle (it will break before it bends). Has anyone run into this issue? I was wondering if I could shim the top the the FD mount (beer can or something that will adopt the curved shape). The bike tech said this would probably slide out eventually due to vibration. Any suggestions on how I can fix this?

Thanks to all!

[ultraman6970]

Seen a problem like this before and the guy shimmed it with a piece of plastic.

[e-RICHIE]

Take a file and reshape the alloy male area that mates within the braze-on.
It should take a minute. Less if you hold it up to a belt sander atmo.

ps

arrange disorder

:rolleyes::rolleyes::rolleyes:
;););)
:cool::cool::)

[kramnnim]

Really doubt that a shim would vibrate out of place...

[Louis]

Really doubt that a shim would vibrate out of place...

Agreed. However, I think Richard's idea to modify the f-der is a more elegant solution. (assuming you don't plan on using that f-der on another bike)

[thirdgenbird]

If you are unsure about how long you will keep the frame, I vote wedge shape shim that gets pierced by the mounting bolt.

If you know the frame is sticking around a while, file the FD.

[rccardr]

Who has successfully bent these a little bit for better alignment?

Rag for paint protection, large crescent wrench properly adjusted, easy but firm pressure, voila!

Done it more than once, never had any later issues. What am I missing here?

[buldogge]

There are small alloy wedge shims made for just this situation.

SRAM makes a 4deg one and Rotor make a 2deg (I believe).

-Mark in St. Louis

[oldpotatoe]

that it won't break but I have bent many fder tabs to correct what you are seeing. BIG adjustable wrench, over whole tab and gently, gently pull wrench aft..Have only broken one, and that was on a riveted on on an aluminum frame and it was so poorly put on(new frame, BTW), that it had to move a bunch..and broke a rivet.

Another solution is sram makes fder shims that go underneath the fdr where it attaches to brazeon..that will also correct this..ahhhh, see above, Mr Buldogge even has pix!!

[Lugger]

There are small alloy wedge shims made for just this situation.

I like this!!!!! Thanks for the tip. I did a google search on many variations of "FD shim" and didn't get any hits. I'll renew my search. Conjuring up a plastic shim was my next best alternative, but this seems much more solid.

I Believe the best performing solution would be bending the braze on as several suggested, or filing the FD mount as others suggested (since those would not result in pushing the FD back an mm or two). But to be candid, I'm a little nervous about either of those approaches. I'm most afraid of the bending, as I 'd fear doing serious damage by dimpling the seat tube or snapping the braze on. The filing of the FD is a little less scary since I could always purchase a new FD if I screw up.

But I think the SRAM shim will be a good first try. I'll post back on the results in case someone else runs into this issue.

Thanks to everyone for the great responses! I love this forum! :hello:

[saab2000]

Take a file and reshape the alloy male area that mates within the braze-on.
It should take a minute. Less if you hold it up to a belt sander atmo.

ps

arrange disorder

:rolleyes::rolleyes::rolleyes:
;););)
:cool::cool::)

This looks like a good suggestion from someone who has a bit of experience working with frames and metal.

[e-RICHIE]

This looks like a good suggestion from someone who has a bit of experience working with frames and metal.

I would never (ever) bend the braze-on in question atmo.
That said, the antidote to this gaffe is pretty low-tech.

ps

arrange disorder

:rolleyes::):rolleyes:
:):rolleyes::)
;):cool::p

[happycampyer]

This looks like a good suggestion from someone who has a bit of experience working with frames and metal.e-Richie is like the House of framebuilding.

[Lugger]

e-Richie is like the House of framebuilding.

Totally agreed! And if Mr RS was doing the filing, I wouldn't hesitate as I love the frame. However, I'm a bit of a clod when it gets beyond using a wrench or a screwdriver. :( Filing (or bending stuff for that mattter) makes me nervous. Since the FD isn't too expensive to replace if I goof, I may get my nerve up to try it. But first attempt will be finding these elusive FD mounting shims.

[Tony T]

I like this!!!!! Thanks for the tip. I did a google search on many variations of "FD shim" and didn't get any hits. I'll renew my search.

Better yet. google images (https://www.google.com/search?tbs=sbi:AMhZZitnEe_1whtZOx6C0RyFQfqjNwOA-wZtB4iWLRGXqAxl58xrU64VG6wNHhdT4fspmIICkU6_1ofUdJZ i7q8x4twaDh0tj8GIifoBR2R5XcR9rEElyL0pZ85_1BOlFK84i BI-ylHrDx2846LViEp_1sxLRgFGT2wmxpH9WiStdy6f5KMEjyvcoN ci8_16uW2zZ4XCfDJFRNd4_1QcEBcCiWurI_14I1nNMVYWQbg8 4yu16zLT41nD9-1ZAudv1_1WAP5r-mWduxOaOvW14KJ7Ms1IdE1JEVUU-ec4PQpD5F7MhfNgjwP_1oH7i1fJEZga5SJtUWdJNEihvEpU6_1 QQcbCnxZt3YfETE9S0JCFwQ5HROfX_1vKa5LpSkLv6CJBlRG9P vzm4Uo-7-ly9Q1IxLT7WK-49iN1ngf9yHAOU8Qlbe4qQoae7nAIzDAhbMvkc2mIRroFP2yUn y5pd2XukKyuZdwbzdBRKI_1vaMYSdA_1l8Byz0nH5ZjHxoRhsP XiYuNnkZpBUNpVS5TUfeRuskbsFksfLsaSvoaLvfEYlMhjuVHE hyJGIn96EPlcvgfakqaI75B3uvD_18ugkFzIb9gAuPtWJSKrXp yvlo9g39MD-1bmEjjBcbWqJjM4kBNUca3lA8qVJF7wYXWZjW0L9AR_1u-waeSRWqoJKsI3rSP5sbBv8E2xFZwDJkwogAqkSEL7H3YLYEDxi 0R4iKEKiCABu4_1EdTI3C23H1neij68pCmIy-Ln6AkOk34Z4ykQapEbYH3fanhSmt8p8zlvaHP5-6fVh_1gD9mn2ccOJa8T2cVo6Xlh8W13ZLWjKMlmK_1cnctbDja vDP5rbVlHpEPJ-wSiFgC4enbCmlHTwtPzzXP43APYLRvn3JyiZ_1C_1NBGGLqXow OEk7l30yfHXoUsc2wwsX9UNk-RmVYCPm3t7Cy5vtbfWxnpPDG30cr_12dp_1G21utbgS1gKmnlq um0lUJtdG19mFL9zlkBnFVyjvOj8c90sCIhxgOy_1glwcRU6Fz zpofYffNUlVazHOIyO9qNTGv6PFd7-560ywjkTtODCyM4_1rRwWvXMSop9ZZAXIK2CVAI4kHB4G_1d0N ayWAEr9yXuSZRXx0pomtzwpeIniZDiuM2QGAhMS02oUmYiX-uvo)

edit: …not as good as I expected, but if did locate this article: http://www.slowtwitch.com/Tech/Front_Derailleur_How-To_3775.html

edit: Here's one: http://shop.osymetricusa.com/Angled-Wedge-Spacer_p_47.html

[saab2000]

Totally agreed! And if Mr RS was doing the filing, I wouldn't hesitate as I love the frame. However, I'm a bit of a clod when it gets beyond using a wrench or a screwdriver. :( Filing (or bending stuff for that mattter) makes me nervous. Since the FD isn't too expensive to replace if I goof, I may get my nerve up to try it. But first attempt will be finding these elusive FD mounting shims.

The shims are a good place to start as you can't unfile the metal. If they don't work you may with to try the suggestion from the guy who has a lifetime of filing experience.

[cnighbor1]

simple fix for Fix for misaligned Braze on
file FD part that attaches to misaligned Braze on
Just file a little of and check alignment than file some more till it is right
best if you use an old not much value FD 1st for practice
or a scrap piece of Aluminum

[Tony T]

Not sure if this was mentioned, but a rat-tail file might be the way to go.
edit: ….never mind, flat file

[cnighbor1]

I would have Mr Richard Sachs simply build you a new frame.
Great fix
Charles

[Tony T]

You got 15 years to wait for that frame? :)

[Lugger]

I would have Mr Richard Sachs simply build you a new frame.
Great fix
Charles

Clearly, THAT is the most elegant solution! ;)

But I'm hoping to ride before 2029 (like tomorrow!) And Anyhow, I could keep on purchasing and filing FDs once a month. I'd hope that I'd get it right by then!

[Lugger]

as you can't unfile the metal

Yeah, that's a pretty good analogy for many things I'd like a second crack at!

[zmudshark]

Maybe a stupid question, but I have run into this before and was perplexed.

If you filed down the FD, would you also have to come up with a solution for the fixing bolt? Some sort of eccentric washer, like a Campy brake caliper washer?

Inquiring minds would like to know.

e-RICHIE?

[ultraman6970]

WOw 1st time I see this as a product... good stuff.

[David Kirk]

I'm pretty late to the game here but I wouldn't bend the braze-on as the penalty for having it go bad is that you get to have a new braze-on installed along with new paint or you get to shop for a new frame. A stamped braze-on will move pretty easily and IF it's brazed on well you could end up OK. If it's a cast piece it will be harder to move (they are generally thicker and designed to be stiffer) and much more likely to pop off the tube or even damage the tube itself.

Filing the derailleur will work and shimming it will work. If you shim it need not be elaborate - a thin 1/4"ish strip of aluminum wrapped over the male part of the derailleur and pinched in between the two parts above the attachment bolt should do fine. If you need more angle change try a thicker piece. It will take a bit of experimenting to get it right but should work fine and be totally reversible so you have no worry about grinding on the derailleur too much.

Dave

[e-RICHIE]

Maybe a stupid question, but I have run into this before and was perplexed.

If you filed down the FD, would you also have to come up with a solution for the fixing bolt? Some sort of eccentric washer, like a Campy brake caliper washer?

Inquiring minds would like to know.

e-RICHIE?

Nah just sight the margin of error, remove that amount from the alloy mating
area on the changer, and draw it up tight so it nests in the braze-on atmo.

ps

arrange disorder

:):):)
:p:p:p
;);):cool: