What's the best way to straighten the derailleur hanger on a steel frame?

[Charlotte]

Long allen key into the mech securing bolt and use that to get the leverage to readjust.

Inelegant, but probably something I'd try on my own bike if it wasn't too precious.

I must say Auntie C, that this thread has shattered some illusions that I held about you. I KNOW that you are a hot assed Fixie Chick. I KNOW that you are a flame haired Amazon, fighting against injustices dealt to the cycling Brother and Sisterhood. I THOUGHT you were Brother Biggsy's right hand dudesse when it came to bike fixing stuff

I'm no Biggsy alright.  Besides, this is Julian's beloved Thorn Brevet we're talking about, so as far as I'm concerned, I'm operating in a zero fuckup environment.  Hence the dumb questions and the proper tool being ordered.

[andygates]

A zero fuckup environment?

What is this mythical place?

[fuzzy]

Long allen key into the mech securing bolt and use that to get the leverage to readjust.

Inelegant, but probably something I'd try on my own bike if it wasn't too precious.

I must say Auntie C, that this thread has shattered some illusions that I held about you. I KNOW that you are a hot assed Fixie Chick. I KNOW that you are a flame haired Amazon, fighting against injustices dealt to the cycling Brother and Sisterhood. I THOUGHT you were Brother Biggsy's right hand dudesse when it came to bike fixing stuff

I'm no Biggsy alright.  Besides, this is Julian's beloved Thorn Brevet we're talking about, so as far as I'm concerned, I'm operating in a zero fuckup environment.  Hence the dumb questions and the proper tool being ordered.

Fairy Nuff.

Do I need to report for 'education'?

[Charlotte]

Only if you want to

[токамак]

Get some pliers on the job? I think that's how me and my dad rectified a bent hanger on a classic and highly collectible Masi 3V Volumetrica after the guy in Italy posted it to the UK in a flimsy cardboard box!

[edit] Oh, hold on - maybe don't try that - now I remember that is was one of the dropouts that had been compressed, not the hanger at all... (But I did take pliers to an Italian classic.)  

[nuttycyclist]

Long allen key into the mech securing bolt and use that to get the leverage to readjust.

Inelegant, but probably something I'd try on my own bike if it wasn't too precious.

...

Unless it is too late - DO NOT DO THIS.


9pm.  I was at the roadside on a dark and rainy night.  Mech went into spokes, 30mph rear locked wheel.  Chain locked taut.  Spoke under major tension.

Only recovery was to remove the mech from the bike.   Chain too tight to risk splitting.

Straightened spoke.  Re-trued wheel.

Replaced mech.  Hanger obviously bent.

Only solution was the allen key.  Hanger is now straight, but the hole is oval and not properly threaded.  I've had to replace the mech with one that has a big nut on the back instead of bolting directly into the hanger.

[Charlotte]

Duly noted, Nutty.

...on a dark and rainy night. 

Was there an old, neglected house far in the distance?  Did you walk there in order to use their telephone?

Was the door answered by a man with a hunchback?

What charming underclothes you have 

[Adrian]

Get some pliers on the job?

And a blowlamp. Oh sorry, wrong film there.

[alexb]

Long allen key into the mech securing bolt and use that to get the leverage to readjust.

Inelegant, but probably something I'd try on my own bike if it wasn't too precious.

...

Unless it is too late - DO NOT DO THIS.


9pm.  I was at the roadside on a dark and rainy night.  Mech went into spokes, 30mph rear locked wheel.  Chain locked taut.  Spoke under major tension.

Only recovery was to remove the mech from the bike.   Chain too tight to risk splitting.

Straightened spoke.  Re-trued wheel.

Replaced mech.  Hanger obviously bent.

Only solution was the allen key.  Hanger is now straight, but the hole is oval and not properly threaded.  I've had to replace the mech with one that has a big nut on the back instead of bolting directly into the hanger.

I've done this a few times. It works fine, but you have to have the rear mech installed and then put the allen key into the socket on the rear mech. I can't see how you can ovalise the bolt hole if you do this.
I can see how it might end up distorted if you insert the allen key into the hole for the rear mech.

[mike]

I've done this a few times. It works fine, but you have to have the rear mech installed and then put the allen key into the socket on the rear mech. I can't see how you can ovalise the bolt hole if you do this.
I can see how it might end up distorted if you insert the allen key into the hole for the rear mech.

that's exactly how the guy in my LBS did it when I took a bike into him expecting it to be a major job.  Took him 1 minute with an allen key into the rear mech socket.

[nuttycyclist]

Re-reads earlier advice carefully as now at work and not concentrating on Red Bull Air Race.

Ahhh, use allen key in mech bolt not direct into threaded hole.  That's what I got wrong      I blame the dark and stormy night 

[fuzzy]

Re-reads earlier advice carefully as now at work and not concentrating on Red Bull Air Race.

Ahhh, use allen key in mech bolt not direct into threaded hole.  That's what I got wrong      I blame the dark and stormy night 

There is a lesson there Nutty, not that shareholders in medical supply companies want you to learn the instruction reading lesson

[nuttycyclist]

This thread was written a couple of years after I mullered my hole in a cold, wet and dark doorway late one Friday evening.

[clarion]

Isn't that a bit OT (& NWS)?

[mcshroom]

I have a similar problem after crashing my Raleigh last week and putting the rear mech into the spokes, but I have the added worry of the mech being held on with a framesaver bolt and epoxy, so I'm not too keen on putting a bending load through the bolt/remnant of the old rear mech.

Am I being to precious about the epoxy, or would it be possible to bend it from a different point using an adjustable spanner?

[mrcharly-YHT]

I think that a spanner is a better tool for the job.  It allows you to choose where to 'unbend' the hanger, so to speak.

[LittleWheelsandBig]

I don't.

The only requirement is that the derailleur thread is parallel with the wheel's axle. There is no need for a threadsaver nut to be epoxied into a hanger as the derailleur bolt restrains the nut.

Just put the normal hanger alignment tool in tight and realign the hanger as normal. The epoxy just makes it slightly easier to screw the derailleur bolt in or out.

[trgz]

Long allen key into the mech securing bolt and use that to get the leverage to readjust.

Inelegant, but probably something I'd try on my own bike if it wasn't too precious.

...

Unless it is too late - DO NOT DO THIS.


9pm.  I was at the roadside on a dark and rainy night.  Mech went into spokes, 30mph rear locked wheel.  Chain locked taut.  Spoke under major tension.

Only recovery was to remove the mech from the bike.   Chain too tight to risk splitting.

Straightened spoke.  Re-trued wheel.

Replaced mech.  Hanger obviously bent.

Only solution was the allen key.  Hanger is now straight, but the hole is oval and not properly threaded.  I've had to replace the mech with one that has a big nut on the back instead of bolting directly into the hanger.

I've done this a few times. It works fine, but you have to have the rear mech installed and then put the allen key into the socket on the rear mech. I can't see how you can ovalise the bolt hole if you do this.
I can see how it might end up distorted if you insert the allen key into the hole for the rear mech.

First time I've bent one (on a Thorn Audax '96) and the hole was ovalled before straightening. Various options open to me so far - hopefully the derailleur will go in and 'bite', next two options recommended are helicoil it or weld and tap it, but not to try epoxy or JB-weld.

[trgz]

Duly noted, Nutty.

...on a dark and rainy night. 

Was there an old, neglected house far in the distance?  Did you walk there in order to use their telephone?

Was the door answered by a man with a hunchback?

What charming underclothes you have 

You're wet...I think perhaps you better both come inside.

[LittleWheelsandBig]

https://www.sjscycles.co.uk/accessories/dropout-saver-threaded-insert-fits-into-rear-mech-hanger/ is the best solution for an oval hole.