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Braze On FD lose plate fittings/FD replacement

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Braze On FD lose plate fittings/FD replacement

Old 09-26-22, 01:47 AM
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Gosh
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Braze On FD lose plate fittings/FD replacement

I have a 2011 aluminium Giant TCR with Shimano 105 5700 double group set. The two fixings in the seat tube for the front derailleur braze-on plate screws are working lose and so there is movement in the FD. I am able to temporarily to fix a cable tie around the FD which does not fowl the mechanism. Iím assuming I can simply replace the FD with a suitable band-on FD but just checking whether there might be any issues. Not sure whether I need to be concerned about any dimensions such as from clamp to cage. As an alternative it would be useful to know whether the fixings themselves can be fixed/replaced easily. Thank you.
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Old 09-26-22, 05:29 AM
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Are the mounts rivnuts?

​​​​​​https://www.google.com/search?q=tigh...kPIPxoWVyAQ_34
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Old 09-26-22, 07:34 AM
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You might want to check the FD hanger for cracks. Another individual with a Giant OCR recently posted here regarding his FD hanger cracking.

https://www.bikeforums.net/bicycle-m...placement.html

Dunno if a crack in the FD hanger could cause flexing that might loosen the mounting screws or not. But it's IMO worth checking that first, since replacing the FD hanger (if necessary) might well be a more elegant solution that's also cheaper than replacing your existing FD with a clamp-on model.
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Old 09-26-22, 07:44 AM
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Originally Posted by Hondo6 View Post
Dunno if a crack in the FD hanger could cause flexing that might loosen the mounting screws or not. But it's IMO worth checking that first, since replacing the FD hanger (if necessary) might well be a more elegant solution that's also cheaper than replacing your existing FD with a clamp-on model.
The OP wouldn't have to replace the entire front derailleur, he would just have to buy an adapter clamp of the correct diameter. Shimano has adapters in 1-1/8" (28.6mm), 1-1/4" (31.8mm) and 1-3/8" (34.9mm aka 35mm). That would work if the seat tube is round and of a common diameter.
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Old 09-26-22, 07:51 AM
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Originally Posted by HillRider View Post
The OP wouldn't have to replace the entire front derailleur, he would just have to buy an adapter clamp of the correct diameter. Shimano has adapters in 1-1/8" (28.6mm), 1-1/4" (31.8mm) and 1-3/8" (34.9mm aka 35mm). That would work if the seat tube is round and of a common diameter.
Understand. But if I recall correctly, Shimano band clamp adapters for braze-on FDs are in the same ballpark cost-wise as a replacement Giant OCR FD mounting plate.

If it turns out the mounting screw holes are stripped or that the bosses are loose, then that's a different story entirely. Then the clamp solution makes sense.

But if the FD hanger is cracked and causing the problem, why not just fix that rather than using a work-around that is visually obvious?
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Old 09-26-22, 09:22 AM
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Thanks dedhed hadn’t seen video before or heard of cap screws. I’ll check how my FD is fixed
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Old 09-26-22, 09:27 AM
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Thanks Hondo6. The bracket is not cracked. I think it’s the bosses (wasn’t sure what the correct term for the fixings we’re) that are loose. Dedhed’s might have a solution for that as above
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Old 09-26-22, 09:28 AM
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Thanks HillRider. Didn’t release there were adaptor clamps will check out.
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Old 09-26-22, 11:33 AM
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Unfortunately I don’t think the band clamp is going to work as on this TCR as the seat tube is tapered. At the top it is round and is about 34.9mm but the section then changes to something more rectangular and is about 40mm where the braze on bracket is.
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