Sito

Hi guys

in an unfortunate turn of events I had my rear derailleur come off today, without any obvious reason. I heard a noise looked around and the derailleur was just dangling there and the derailleur hanger was bent. The bolt that holds the derailleur had stripped out of the hanger.

So the hanger obviously needs to be replaced and I have already ordered one. But I am not sure what to do with the derailleur. I have attached a photo which I hope shows the damage. The bolt is stripped and needs replacing and also the little bit that hold the screw that allows you to adjust the angle of the derailleur has broken off. If I am not totally mistaken you can buy the "B-Axle Assembly" for this derailleur as a spare part and that seems to cover all the parts I need. However, this doesn't seem to be available through any online merchants in Spain, where I am based right now, and I am sure my dealer is going to charge me more for those few parts than an Ultegra derailleur would cost me....

So, I would be very interested in your view. Is my assessment above right? Is this reparable? Is it worth repairing?

Any opinions are, as usual, much appreciated.

Lars

alcjphil

The bolt is made of a harder material than the derailleur hanger, so it is unlikely that it is stripped, what you see is from the stripped threads of the derailleur hanger. Odds are that if you take a wire brush to the threads on the derailleur they will clean right up. As to whether the rest of the derailleur is damaged, you will only find out when you bolt it back on

CliffordK

Clean up the derailleur and inspect carefully.

Here is Shimano's parts list.

https://si.shimano.com/php/download.p...9000-3330A.pdf

What is the mounting bolt made of? Steel? Titanium? I agree with alcjphil that you can likely clean up the threads of the old bolt.

Here is the entire B-Axle assembly.
Shimano Dura-Ace RD-9000 B-Axle Assembly - £29.99
Shimano Dura-Ace 9000 11-Speed RD-9000 B-Axle Assembly - Y5XX98010 - Newegg.com

It looks like Shimano lists the B-Screw separately, but not the retainer which is apparently broken.

The 6800 and 9000 appear to have quite a different design for the B-axle assembly. It is possible that B-screw part would interchange, but you'd probably have to disassemble and compare the actual parts.

alcjphil

Yikes, I missed that, good catch

Sito

thanks, guys, good to know about the stripped bolt. I guess I'll talk to the mechanic tomorrow and find out what he can do...getting the bike back on the road asap is really the priority, got a big event coming up on the 10th :/