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Rear drops/hanger bent beyond repair?

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Rear drops/hanger bent beyond repair?

Old 10-20-16, 02:19 PM
  #1  
jazzyman
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Rear drops/hanger bent beyond repair?

I bought an old steel peugeot the other day and noticed that the rear drops and hanger are pretty messed up. Is this something that can be fixed, because it's not just the hanger that is bent but also the slot for the rear wheel. I was thinking of sticking it in a vice and then tighten it as hard as I can to see if it flattens the area.
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Old 10-20-16, 02:41 PM
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Steel is often quite forgiving. But there's another big unknown here - your skill.
Shops have tools both for dropout alignment and derailer hanger alignment. And probably the skills to go with them.
Me, I'd probably go at it with a big adjustable wrench or two. But I have considerable metalworking experience.
Depending on how tight the bends are, it might not be possible to get it flat enough by squeezing the dropout in a vise. Metal often need a bit of overbending to stay where you want it.
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Old 10-20-16, 02:45 PM
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You should (might?) be able to straighten the drops and hanger enough using a vise and some large locking pliers. A large, strong assistant might also be helpful. Once you get it straightened sufficiently, this should serve to restore the derailleur threads: Dropout Saver
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Old 10-20-16, 04:11 PM
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Tap the back of the RD hanger with a hammer to close up the wheel slot, then use an adjustable wrench to get the dropout flat again...
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Old 10-20-16, 04:58 PM
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I've used a DIY method similar to this for dropouts: https://youtu.be/PsU8IkkFaok

And this method for hangers: https://youtu.be/WS2vd8N1Vos

Use an XL adjustable wrench (or 2) to bend steel dropouts & hangers. If you try to bend using all thread rod, the rod usually bends first. On aluminum dérailleur hangers the all thread works fine. One time mend only on those.
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Old 10-20-16, 05:06 PM
  #6  
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It looks to me as if the offset is normal. You still have it a bit twisted, but you don't need to get rid of the offset.

Some derailleurs had a lock nut behind the derailleur hanger (and trying to remove the derailleur without taking that into account could be a problem).

If all else fails, you can cut the derailleur hanger off and use a "claw", although your dropout slots are a bit on the short side. It'll probably be ok if you have adequate wheel clearance with the wheel mounted forward in the slots.
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Old 10-20-16, 05:52 PM
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Originally Posted by CliffordK View Post
It looks to me as if the offset is normal. You still have it a bit twisted, but you don't need to get rid of the offset.

Some derailleurs had a lock nut behind the derailleur hanger (and trying to remove the derailleur without taking that into account could be a problem).

If all else fails, you can cut the derailleur hanger off and use a "claw", although your dropout slots are a bit on the short side. It'll probably be ok if you have adequate wheel clearance with the wheel mounted forward in the slots.
Yeah this derailleur (think it is a simplex) had a lock nut behind the hanger, made an awful noise when i was trying to take it off before I realized it though. The previous owner probably must not have known how a QR worked and tightened it crazy hard in the open position, think that's what messed up the drops. So before I go to town on this thins the offset/bend i have highlighted in the attachment should be there?
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Old 10-20-16, 06:02 PM
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Put your locknut up next to the derailleur hanger.

It probably fits perfectly into that offset area.

I can't say if it is necessary, but you have a thin pressed steel dropout, so the locknut was probably making up a bit for benefits of thicker forged designs like the Campy dropouts.
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Old 10-20-16, 08:26 PM
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It may be the angle of the picture but the threaded portion of the derailleur hanger looks stretched out of shape. If not, I would straighten the dropout, install the wheel, install the derailleur then base the adjustment from there.
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Old 10-20-16, 09:48 PM
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Originally Posted by jazzyman View Post
Yeah this derailleur (think it is a simplex) had a lock nut behind the hanger, made an awful noise when i was trying to take it off before I realized it though. The previous owner probably must not have known how a QR worked and tightened it crazy hard in the open position, think that's what messed up the drops. So before I go to town on this thins the offset/bend i have highlighted in the attachment should be there?

A few comments- Simples ders usually have a top knuckle spring that can be damaged wit too much rotation during removal/spring adjustment. Don't know if this was the noise you heard but...


Your photos have a shopped in line that references at it's top the drop out's portion that engages the seat stay. This portion has nothing to do with the axle faces or the der mount tab face. Sure it might be a nice point to try to see the rest of the situation from but it's wrong.


QR only wing nutted tight (and the reality is the tighter it's wound up the less the likely damage) had nothing to do with the drop out damage. This damage needs a strong levering force. The typical is a der caught up in the spokes and the momentum of the rider further causing rear wheel rotation. This makes the axle move rear and down wards, bending the drop out.


The repair should be a simple but not quick blacksmithy job. With vise grips or hammering establish the der mounting tab back to a round hole. Then flatten this tab. Then close up the axle slot. Then correct for the twisting and 3D nature these steps tend to become. Then repeat all. Then align the drop outs to parallel. Then check general front and rear triangle alignments. A run through the tab's threads with a tap might be needed.


If done well all will line up and be ready for the parts to be reinstalled. If hacked then... Andy

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Old 10-21-16, 06:01 AM
  #11  
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I'd recommend putting a proper sized bolt in the derailleur hanger hole before bending on the hanger.

What you don't want to have happen is for that hole to get ovalized.
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Old 10-21-16, 08:30 AM
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That's really not that bad, I've done much worse and bent it back with out it breaking off. You will need an alignment tool if you want to be accurate and have your shifting work ok. The threads look messed up, so running a tap through will probably help too.
Use a large adjustable wrench to bend the axle slot in to position first, then the hanger.

Good Luck.
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Old 02-02-17, 06:24 PM
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So I took your guys advice and went at it with an adjustable spanner (crescent wrench). However, because I was afraid of snapping it I was getting nowhere. So instead I took it to a bike shop. Had to go to three different shops before someone was willing to touch it. Essentially you guys were right, the guy used a crescent wrench, vice and hammer but was a hell of a lot more brutal than I was. At least I know for next time how much a steel frame can take. Amazingly the threads still worked but the guy at the shop recommended I used a thread locker so I don't have to tighten the RD to tight just in case.

The problem I have now is that the High Gear Limiting screw is not long enough because of how bent the derailleur hanger is. The guy didn't think making the hanger "flat" was a good idea considering the hanger was parallel with the wheel and trying to straighten it might snap it. You can see the bend I'm talking about in the previous images I uploaded. So when I shift (dt friction shifters) the chain jumps passed the smallest cog and off the freewheel. Anyone got any tips or tricks, the rear derailleur is a Campagnolo Chorus.
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Old 02-02-17, 06:55 PM
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The derailleur's limit screws should take care of the overshifting if the hanger is in the ballpark. Did you adjust them?

Edit: My apologies for completely missing that you'd already tried the limit screw. Carry on . . .

Would shortening (tightening) the shift cable help?

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Old 02-02-17, 07:21 PM
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Will a longer screw work?
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Old 02-03-17, 12:09 PM
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Originally Posted by Bill Kapaun View Post
Will a longer screw work?
That's what I was thinking but where would you buy one?
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Old 02-03-17, 12:13 PM
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Originally Posted by jazzyman View Post
That's what I was thinking but where would you buy one?
A screw store.
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Old 02-03-17, 12:18 PM
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Originally Posted by jazzyman View Post
That's what I was thinking but where would you buy one?
Don't know where you're located but in the US, ACE hardware has an excellent selection of metric fasteners. Remove the limit screw and take it with you. ACE has templates in their fastener section to determine the sizing of bolts.
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