Damage to rear derailleur........................

[ray316]

l came sliding of my specialized allez road bike the other day and apart from a black eye and brusing down one side it's the damage to the bike that's bothering me...
As l dusted myself down and hopped back on the bike it just clattered as l started to pedal and stopped, l looked at the rear derailleur and the part of the derailleur (it's where the hanger bolt goes) so l presume it's called the hanger is broke..
So a small bit is still attached to the frame by a bolt and the other part which is the derailleur has come away, if l put the two parts together there is no bit missing but how can l repair the damage..
Does anyone have any ideas what l can do to fuse the two parts back together or will l need to get a new rear derailleur...
Will any rear derailleur work or has it got to be the correct one for the back..
Ideally l would like to give it a go at repairing it if possible.. Thanks

 

[deptfordmarmoset]

It sounds like you need a new hanger - they're designed to be weak, like the crumple zones in a car, to protect the more valuable stuff. A quick and relatively cheap visit to the LBS should do it.

 

[Globalti]

The hanger is designed to be weaker than the derailleur or the frame so as to protect them in an accident, same as a fuse in a circuit.

 

[ray316]

It sounds like you need a new hanger - they're designed to be weak, like the crumple zones in a car, to protect the more valuable stuff. A quick and relatively cheap visit to the LBS should do it.

Great.. l did'nt know you could buy new hangers for the rear derailleur... How easy are they to replace, as you can gather l'm not mechanically minded on bikes..
Will the derailleur need setting up again after.
Do you think my local LBS stock this part or will l need to go to a specialist.
The bike is a Specialized allez elite, about 8 years old.

 

[deptfordmarmoset]

There's a video on replacing a hanger HERE - I've never done it but it looks like all you need is a 5mm key.

And HERE's a selection of dérailleur hangers. I'd give your LBS a call and see whether they have one in stock.

 

[gbb]

Yup, almost certainly your hanger (by your description)
Remove the broken bits, fit your new hanger then fit your mech to the hanger. I dont think you'll have to disconnect cables or anything, so hopefully nothing should need adjusting...
Hanger for my Bianchi...£25. Thats a premium price really, LBS had it in stock. I could have saved some perhaps by buying online, but in stock locally...i dont mind paying that bit extra.