Bent aluminum hanger. Help please!

[madjh]

I would not recomend to do your self. Of course I have bend one and of course I have tried to fix it. It usually look good but for some reason the derailleur didn´t chage as well as when it was straight.

In a shop they use a compass and with the wheel they will fix it. The aligment is with the rim. If you usually visit one bicycle shop, there are chances that they will not charge you anything.

 

[M_Chavez]

Yep, the compass alignment tool is the way to go.
Very cheap ones are not very accurate, but for 7-8-9 speeds you don't need to be perfectly accurate.
Aluminium might crack very easily when bending back. (Steel is real, my friend. Steel is real.) If that happens, your two options are to either retrofit a screw-in hanger, or replace the frameset with a steel one. You can also replace the frameset with a steel one.

Just don't ride it if it's visibly bent, unless you want your cage jamming in your spokes, like it happened to me last year when I was trying to get home after dropping the bike onto the rear mech

 

[79stef]

I hear you, but I'm invested in this frame now and I'm not giving up!
This is why I posted for advice on here as I am aware of the brittle nature of aluminium and I know there is a lot of knowledge within this forum.
LBS is my first port of call.

Yep, the compass alignment tool is the way to go.
Very cheap ones are not very accurate, but for 7-8-9 speeds you don't need to be perfectly accurate.
Aluminium might crack very easily when bending back. (Steel is real, my friend. Steel is real.) If that happens, your two options are to either retrofit a screw-in hanger, or replace the frameset with a steel one. You can also replace the frameset with a steel one.

Just don't ride it if it's visibly bent, unless you want your cage jamming in your spokes, like it happened to me last year when I was trying to get home after dropping the bike onto the rear mech

 

[novocaine]

aluminium is as far away from brittle as it can be, it's malleable, but it's plastic modulus isn't great, once it's yield point is exceeded it doesn't like to be moved back, it "work hardens" copper does the same thing. you'll be looking for about 2mm of movement max, it's well within even hardened aluminium to be adjusted in this way.

still say "let the LBS do it" but only because they've done it hundreds of times before and know the limits better.

as to accuracy of cheap one's, it's a bar with a thread on it and a stick, there is nothing to be inaccurate.

 

[79stef]

aluminium is as far away from brittle as it can be, it's malleable, but it's plastic modulus isn't great, once it's yield point is exceeded it doesn't like to be moved back, it "work hardens" copper does the same thing. you'll be looking for about 2mm of movement max, it's well within even hardened aluminium to be adjusted in this way.

still say "let the LBS do it" but only because they've done it hundreds of times before and know the limits better.

as to accuracy of cheap one's, it's a bar with a thread on it and a stick, there is nothing to be inaccurate.

I stand corrected...chemistry has never been my strong point!

 

[novocaine]

I stand corrected...chemistry has never been my strong point!

don't worry about it, it's not really an issue anyways. go get it sorted already.

 

[79stef]

Soon as I get back from Amsterdam, I'm on it... If I remember...

 

[79stef]

Update: took it to my LBS who fixed it for £15.
Sorted.
In think I'll invest in the alignment tool anyway as it will be worth having for checking alignment of frames as well as fixing them

 

[bikeworkshop]

Don't buy the park one,

it's over-complicated and bits fall off it.
My favourite is the old campag one,

takes a little more skill to use, but it's not hard, and one you've got it, it's easy.
There are copies available new if you don't want to start a retro toolkit.
Assuming it's possible to copy a bent stick with a twizzly thing on the end

 

[79stef]

Don't buy the park one,
View attachment 855018
it's over-complicated and bits fall off it.
My favourite is the old campag one,
View attachment 855019
takes a little more skill to use, but it's not hard, and one you've got it, it's easy.
There are copies available new if you don't want to start a retro toolkit.
Assuming it's possible to copy a bent stick with a twizzly thing on the end

Thanks for the advice. The Campag one looks solid... but why would you put the idea of a 'retro toolkit" in my head??! Retrobikes are financially draining enough!!