Bent rear derailleur?

[LeadFarmer]

Anyone think this derailleur looks bent, and would it be repairable, or do I need a new one?

Changing the chain today on my 11 speed bike and decided to inspect the rear derailleur as I had been feeling/hearing some grating noises lately.

To me it looks slightly bent, and the chain looks like its catching on the inner plate right at the bottom. When holding this part and spinning the crank I can feel the chain catching. Replacement derailleur is £70 - £80 so not cheap.

I've tried twisting it with pliers but without success...

[Barchettaman]

Whoah. Stop right there. Is the derailleur hanger bent?

That’s more likely than the derailleur cage being bent outboard.

[Wilmslowboy]

Looks like the cage could be bent (which you can check by dismantling it and laying on a flat surface)

However as said in the post above, worth checking the sacrificial hanger first (magnesium part),which could be causing the whole derailleur to sit out of line.

[Drezza]

Could you not just put a straight edge ruler against it rather than taking it off to check if it's bent, personally I'd just bend it back with some mole grips.

[cs174]

It's likely the hanger that's bent, cheap and easy to fix

[Indoraptor]

It looks like the cage has taken a whack. That’s a massive PITA when it happens. Try straightening the hanger first, if that doesn’t sort it, you’ll need a new cage.

[LeadFarmer]

I posted this photo on the cassette cleaning thread, but it's more relevant here, and is the likely cause of the bent derailleur....

Last January whilst cycling home form work I had an almighty bike fail, a broken chain link probably jammed in the derailleur, ripping it off the hanger and wrapping it around the cassette.




At the time the derailleur looked ok, but I replaced the snapped hanger, fitted a new cassette and bought a supposedly better chain (£35), I also fitted a new front chainring. I was hoping the derailleur itself was ok as I'd spent more than enough £££ already. It seemed ok for the following 2 months, and then lockdown came and I no longer used the bike to commute.

Fast forward to the other day when I took the bike out and the expensive new chain broke, most likely from rubbing no the derailleur, perhaps because the jockey wheel bearings have probably failed?




So having fitted the new chain I then noticed the bent derailleur, so I have ordered a new Shimano derailleur at £70. This aint a cheap hobby is it

Edited by LeadFarmer on Sunday 31st January 16:39

[Jimbo.]

I believe you can order new cages for mechs.

[LeadFarmer]

Jimbo. said:

I believe you can order new cages for mechs.

Thanks, I actually found a local supplier of the cages, but having paid for new cassette, hanger, chain & chainring etc and due to the severity of the derailleur crash, I've decided to buy a new derailleur for the full set.

Edited by LeadFarmer on Sunday 31st January 16:56