bent derailler hanger

[tazz]

 my replaceable derailler hanger is bent can they be straightened if so which is the least risky

[DawieO]

They can but it is seldom successful.

 

New ones are normally fairly cheap.

[dirtrider]

Some people claim to bend theirs straight all the time . I suppose it depend how bend it is . Last one I tried to bend broke at the next ride .

[tazz]

 My bike is a Schauff hardline PH 1 so i'm battling to find a supplier any ideas of who to try

[Bat-ass]

they can straighten it no prob.....

your LBS should have the right tool.

PRO riders hangers are forever getting bent in crashes and transit, the mechanics straighten them all the time...

[DawieO]

Yeah they use that long lever with the guage that runs around the wheel, but it only really works if the bend is minor.  Also, every time you do this the hangar weakens and then...

 

walking home.

[Johan Bornman]

Bending back those sacrificial aluminiun hangers is seldom successful. This is because the aluminium work-hardens in the bend. Bending it back thus means it bends in a different place. You may get it straight, but now the alignment with the frame has a gap in. Tighten your QR and the jockey moves.

 

Ideally you need a new hanger and someone with the know-how to bend the frame - these often bend as well, even though they're not supposed to. It is easy to see if the frame is bent - the new hanger will have a gap or, the jockey will move as you clamp the QR.

 

In your case, straigtening is the only option so:

 

1) Remove the hanger and hold it next to a straight edge of sorts.

2) Decide where the bend is and mark it with your son's wax crayon.

3) Now place it on a flat surface with the bulge upwards.

4) Hammer it with a suitably large pin punch - not directly with a hammer, that's not accurate enough.

5) Inspect it next to the straight edge and repeat until straight.

 

Note that hangers do not only bend sideways, but also forwards/backwards. The latter is due to mechanics overtightening the jockey anchor bolt without supporting the assembly.

 

On anodised derailers it is easy to see where the bend is since the anodising would have crazed in the bend. Crazing is those fine cracks on the surface of bent anodised things.

 

Don't assume the frame is not bent just 'cause you have a replaceable hanger.

 

 

[Goodbadugly]

Bend it back. Order a new one as a spare. If the "fix" did not work, replace it with a new one. Nothing to be lost in trying to fix the bent one.