Cracked shimano DI2 front derailleur

[AnthonyD]

Hi,
I got a cracked shimano DI2 front derailleur (see picture attached). I try soldering it but no luck (probably don't have the right solder). Any suggestions on how to fix that please?
Thanks

   

[ReapThaWhirlwind]

You might be able to use epoxy putty.

BJ Weld or the sort.

That plus a c-clamp to hold it together while it cures.

[Sybian]

(02-06-2023, 03:08 AM)AnthonyD Wrote:  Hi,
I got a cracked shimano DI2 front derailleur (see picture attached). I try soldering it but no luck (probably don't have the right solder). Any suggestions on how to fix that please?
Thanks

Do not waste your time with soldering, epoxy glue, or JB Weld if you want it to hold together for any period of time. Take it to a welding shop or an automotive repair shop who has someone experienced at welding and get it done right. If it is disassembled and ready for them, it won't take but 5 minutes from start to finish. It should not cost more than $10. You can file away any excess to maintain proper clearance and function.
If a shop wants to charge you more than I would check on a replacement part.

[enkei]

(02-06-2023, 09:12 PM)Sybian Wrote:  Do not waste your time with soldering, epoxy glue, or JB Weld if you want it to hold together for any period of time. Take it to a welding shop or an automotive repair shop who has someone experienced at welding and get it done right. If it is disassembled and ready for them, it won't take but 5 minutes from start to finish. It should not cost more than $10. You can file away any excess to maintain proper clearance and function.
If a shop wants to charge you more than I would check on a replacement part.

I think Sybian is right. Welding is your only hope.

Alas, IIRC, that part is riveted to the rest of the mech. By the time you drill out the rivets, get the part welded up (if it works - the chrome needs to be removed, then the part welded, etc), clean up the weld, and figure out how to reinstate suitable rivets, the whole job will have cost more time and money than buying a replacement mech, especially as I think used ones are quite cheap on eBay (depending on the model).

I'm wondering how this happened? Has the chain been wearing on that guide? It looks like the bike needs servicing, generally, or you'll simply end up with more broken expensive parts. Apologies if my interpretation of what I see in the photo is off the mark.

I had a look for replacement chain guides. The spare guides I found are twice the price of the entire mech!!!