Derailleur Hanger cracked, Canyon Aeroad. Possible causes?

[Shrike]

Spotted this today when putting the bike on the Neo. Wondering on possible causes. Bike has a lightweight rider (sub 60kg) and hasn't been crashed.

Could it be related to indoor trainer use? Other possible cause I'm thinking is that we put an 11-32 on it last year with eTap. It seemed to work fine. Had a few rides but wasn't entirely happy with it so it has an 11-28 or 11-30 usually (11-30 isn't recommended but seems good, though wondering now if this is stressing it even if the 30 is only used with a 34 up front).

Can you tell anything by the type of crack that's appeared on it?

[alcatraz]

Looks like the hanger bolts are too short. They would provide a bit better structural support if they were almost all the way through. It's possibly also a design issue as the hanger is partially hollow and has a hole very close to the edge.

If the hanger was realigned without being clamped it could start small cracks to form that later with an overtorqued short bolt and the vibrations from rear wheel and rear derailleur expanded to a large split.

Just a theory. I'd use longer bolts correctly torqued and if I align the hanger I make sure the wheel is clamped tight before I do so.

It's also possible that there is too much play between an unbolted hanger and the frame. It means when you really tension the skewer there is little internal support of the two sides of the hanger and the whole hanger gets kind of crushed. So make sure you can't wiggle the new hanger much sideways when you place it in it's position.

/a

[alexmcm09]

Check your rear derailleur cage isn't rubbing on the Tacx Neo body. I'm running a 30t cassette with a long cage derailleur (albeit Ultegra Di2) and the derailleur cage rubs the plastic body of the Neo, pushing the derailleur out and stressing the hanger. So now I just don't use the largest cog.

[Broady]

Canyon manual says not to use on a turbo for reference, probably to cover their own backs though.

[Vermu]

Canyon manual says not to use on a turbo for reference, probably to cover their own backs though.

Almost all manufacturers say so.
Been using my aeroad and ult on trainer without issues


Sent from my iPhone using Tapatalk

[jekyll man]

User error.

Shrikes got previous for dropout damage and trainer use.

Could be just coincidence though.