Bent aluminum hanger. Help please!

[79stef]

I'm at the end of my build and today I tried to dial in my index shifting. The bike struggled to drop from 2nd highest to highest (smallest) cog.
I changed both shifter and derailleur but exactly the same problem occurred. Then I noticed the hanger (dropout? - unsure of correct terminology) looks bent.

I'm reluctant to use the 'two adjustable wrenches' method as the bike is aluminum and bonded and I fear my heavy hand may do more damage than good.

Can anyone point me in the direction of a shop/frame specialist that may be able to help? I'm London based, so the closer the better as I'd rather not post it and risk further damage.

I'm not going to give up on this frame just yet as; it's the correct size for me, I spent hours upon hours polishing it, and I have been pulling my hair out collecting Suntour XC bits for it!
Thanks

 

[novocaine]

Almost any bike shop will have an alignment tool these days. Take your pick. If they don't, they'll know the next nearest that does.

You'll not get it accurate with an adjustable spanner.

 

[79stef]

Thanks @novocaine - I'll try my local bike shop and see if they can help

 

[ishaw]

I'm not sure what the adjustable wrenches method is, but I've used a different method which while typing, enhanced. Maybe I read it somewhere, maybe my brain does work?

So, my previous method is using a threaded hub axle. It fits the threads of the hanger. Thread it through and you have the ability to adjust on infinite plains using it as a lever. This has worked for me just by eye, but my enhancement is to add a flat washer or plate and bolt against each side of the hanger. The flat plates will give you an indicator of where the hanger is bent. You can then align using the axle as a lever, in very small increments, adjusting the bolts and plate as you go until straight. Or perhaps even tighten the bolts up, so that the plates align the hanger?

The hanger doesn't look too far out, and you'll not need to put a lot of force through it to align. Keep the wheel in place to keep the frame aligned and you should be golden.

 

[79stef]

I'm not sure what the adjustable wrenches method is, but I've used a different method which while typing, enhanced. Maybe I read it somewhere, maybe my brain does work?

So, my previous method is using a threaded hub axle. It fits the threads of the hanger. Thread it through and you have the ability to adjust on infinite plains using it as a lever. This has worked for me just by eye, but my enhancement is to add a flat washer or plate and bolt against each side of the hanger. The flat plates will give you an indicator of where the hanger is bent. You can then align using the axle as a lever, in very small increments, adjusting the bolts and plate as you go until straight. Or perhaps even tighten the bolts up, so that the plates align the hanger?

The hanger doesn't look too far out, and you'll not need to put a lot of force through it to align. Keep the wheel in place to keep the frame aligned and you should be golden.

This seems like a sound method which I might try. I have tried to press the bend flat using 2 pieces of hardwood and a vice but it didn't work.
I think that I need the leverage of an axle or similar to get things right and I like the plates idea.
I'm still 50/50 on whether to try myself or take it to a shop but I'm away from the bike for a few days so can mull over it and decide whose fate the bike will be left in!

 

[Grannygrinder]

I'm not sure what the adjustable wrenches method is, but I've used a different method which while typing, enhanced. Maybe I read it somewhere, maybe my brain does work?

So, my previous method is using a threaded hub axle. It fits the threads of the hanger. Thread it through and you have the ability to adjust on infinite plains using it as a lever. This has worked for me just by eye, but my enhancement is to add a flat washer or plate and bolt against each side of the hanger. The flat plates will give you an indicator of where the hanger is bent. You can then align using the axle as a lever, in very small increments, adjusting the bolts and plate as you go until straight. Or perhaps even tighten the bolts up, so that the plates align the hanger?

The hanger doesn't look too far out, and you'll not need to put a lot of force through it to align. Keep the wheel in place to keep the frame aligned and you should be golden.

Thats pretty much exactly how I do it

 

[novocaine]

if your going to do it yourself then just buy the right tool (or make one, mine's home made).
it threads in to the hanger, you reference of the wheel (I use the valve stem), spin the rim and tool to the other side of your plane and adjust, spin back and do it again. do this at top bottom front and back then a few times at other angles to be sure.

that's it, done, no eyeballing, no nearly right, no heavy work.
or pay the 10 to 15 quid that your local bike shop will charge to do it. (sorry, you are in london, make that 100 to 115 quid )

cheapest on shamazon

https://www.amazon.co.uk/Derailleur-Alignment-Mountain-Bicycle-Calibration/dp/B08HQK1T18/ref=sr_1_17?crid=I8Y8W8LMQRV6&dib=eyJ2IjoiMSJ9.14NvLtAiOO_Pa06FqxxicmPysZx_UTXbLCpopRfG2m1X0GDyCEKtVidQaJFOmO7zNnpDwk7xC-5V37sc4HPOPkVnrYfiNPT3QtRxKxWYiJnTYXSWQvDyHFuzXj5xw6gf7NI4mYAywTRzNbCdP_MauRzYT-zPf7CRO2bcFwL5z1ysdT9raWtINq4Y3vESaen0LkIOMPNNhiiKZiAB_b1Hq1V5md64XQR4LKC_Vztw0gI6215hCEXygRM-35c3LHxxT-f1O6qfw7KmY9pAllM8XUaZb3hwOcbQ1xOtedc4xbk.ri90WKea7IaqCR7mjxbhr_qwsIUdaMhbAZlvG1PHims&dib_tag=se&keywords=derailleur%2Bhanger%2Balignment%2Btool&qid=1715844982&sprefix=derailleur%2Bhan%2Caps%2C246&sr=8-17&th=1

 

[79stef]

if your going to do it yourself then just buy the right tool (or make one, mine's home made).
it threads in to the hanger, you reference of the wheel (I use the valve stem), spin the rim and tool to the other side of your plane and adjust, spin back and do it again. do this at top bottom front and back then a few times at other angles to be sure.

that's it, done, no eyeballing, no nearly right, no heavy work.
or pay the 10 to 15 quid that your local bike shop will charge to do it. (sorry, you are in london, make that 100 to 115 quid )

cheapest on shamazon

https://www.amazon.co.uk/Derailleur-Alignment-Mountain-Bicycle-Calibration/dp/B08HQK1T18/ref=sr_1_17?crid=I8Y8W8LMQRV6&dib=eyJ2IjoiMSJ9.14NvLtAiOO_Pa06FqxxicmPysZx_UTXbLCpopRfG2m1X0GDyCEKtVidQaJFOmO7zNnpDwk7xC-5V37sc4HPOPkVnrYfiNPT3QtRxKxWYiJnTYXSWQvDyHFuzXj5xw6gf7NI4mYAywTRzNbCdP_MauRzYT-zPf7CRO2bcFwL5z1ysdT9raWtINq4Y3vESaen0LkIOMPNNhiiKZiAB_b1Hq1V5md64XQR4LKC_Vztw0gI6215hCEXygRM-35c3LHxxT-f1O6qfw7KmY9pAllM8XUaZb3hwOcbQ1xOtedc4xbk.ri90WKea7IaqCR7mjxbhr_qwsIUdaMhbAZlvG1PHims&dib_tag=se&keywords=derailleur%2Bhanger%2Balignment%2Btool&qid=1715844982&sprefix=derailleur%2Bhan%2Caps%2C246&sr=8-17&th=1

I think I'll take it to one of two lbs' that I trust and see what they say. If they start huffing and puffing or wanting ridiculous money I'll attempt a fix myself.

Thanks everyone for your advice

 

[minor_LEGEND]

Good advice above, save me typing it into my ownwords. I will add, it is worth trying a few rear mechs, simply to eyeball how straight or bent the hanger is. Mechs can vary, or even the one you wish to use is not perfectly straight. Just look at 2 or 3 mechs on the frame before jumping in to straighten it.

 

[79stef]

Good advice above, save me typing it into my ownwords. I will add, it is worth trying a few rear mechs, simply to eyeball how straight or bent the hangers is. Mechs can vary, or even the one you wish to use is not perfectly straight. Just look at 2 or 3 mechs on the frame before jumping in to straighten it.

My reasoning for this was that I had an NOS Suntour XC Pro short cage mech and although it looked to shift positively, the older medium cage one seemed to have a slightly stiffer spring so I wanted to eliminate the possibility that the NOS one had a faulty spring or was somehow bent. Both mechs and shifters performed in exactly the way, so through process of elimination, I've put my mind at ease knowing I won't have to bend the hanger and continue to still have the problem!