Threads on derailleur hanger

[Jimmy Welch]

Hi everyone , my derailleur and hanger got mashed at the weekend , I've got a new hanger and derailleur ready to fit but the screws for the hanger won't bite , it looks like I may have done the threads in , any ideas

 

[Roseland triker]

Pics are a bit rough.
Do you mean the threads in the frame won't hold the hanger on?

 

[Jimmy Welch]

Pics are a bit rough.
Do you mean the threads in the frame won't hold the hanger on?

Yes

 

[Roseland triker]

If that's the case if the frame is metal then drill out and helicoil them.

If the frame is composite then you might be able to bond in new threaded plugs...

 

[Roseland triker]

What's it made of?

 

[Jimmy Welch]

What's it made of?

It's alluminium , here is a better photo

 

[Roseland triker]

Hmmm can be problematic.
If you have enough clearance between casette and frame you could bolt through fitting a nylock nut on the back but usually there isn't enough room.
Being aluminium I would very carefully drill out and retap the next size up .
Drill the hanger holes to accommodate the larger bolt and refit it with the next size up bolt.

 

[Roseland triker]

Oh and loctite the bolts in. Once done use a hanger alignment tool to set up before fitting new mech.

 

[fossyant]

As we all know, Jimmy's photo skills are almost as good as his mechanic-ing.

 

[si_c]

Might be worth checking you're fitting it correctly, on all my bikes the threads are in the hanger and not in the frame, so you thread the bolts in from the opposite side and that pulls the hanger into the frame rather than screwing through the hanger into the frame itself.

 

[Roseland triker]

It's a basic repair but does require a small level of skill...

 

[presta]

you could bolt through fitting a nylock nut on the back but usually there isn't enough room.

Then put the nut on the outside, with the head of a countersunk bolt at the back. (Or a pan head may be flat enough to clear without the need to countersink the frame.)

 

[Roseland triker]

Then put the nut on the outside, with the head of a countersunk bolt at the back. (Or a pan head may be flat enough to clear without the need to countersink the frame.)

Yes there are various options.
As the OP said frame threads were buggered I went with the most obvious repair not being able to have it here to view in person

Counter sinking the frame will only make it thinner

 

[Jimmy Welch]

Might be worth checking you're fitting it correctly, on all my bikes the threads are in the hanger and not in the frame, so you thread the bolts in from the opposite side and that pulls the hanger into the frame rather than screwing through the hanger into the frame itself.

I haven't tried that , can everyone else agree to bolt out from the frame rather than into it ?

 

[Jimmy Welch]

Might be worth checking you're fitting it correctly, on all my bikes the threads are in the hanger and not in the frame, so you thread the bolts in from the opposite side and that pulls the hanger into the frame rather than screwing through the hanger into the frame itself.

Ill give it a go