I picked up this damaged bike today. Obviously the derailleur hanger is bent, and I paid accordingly. (I can't get enough of these damaged dropouts!) Worst case, I could sell a couple parts and recoup my costs, but I'd like to try to repair it if possible. The frame is too large for me, so it will be sold in the end. My first instinct is to put the whole rear dropout/hanger in a vise and then tweak from there. It's obviously got a significant bend, but at least it's still there. I have some concern about preserving the threads, so I'm thinking it may be best to re-bend the hanger with a derailleur mounting bolt still installed. What would you do? Advice welcome.

Voted bend! My guess is that it will crack, but it's worth a try.

I have the hanger alignment tool if you need to borrow one.

I wouldn't trust it even if you could bend it back. I'd make it into a fixie or use a claw.

Oh, yeah? That's a tempting offer. Do you prefer beer, wine, or whiskey?

I think you might avoid cracking it if you heat it up with a torch before bending it.......
How much and how long to heat it I don't know, plus there will be no guarantee if the RD mounting hole will be salvageable as it will most like be ovalized and the threads deformed, but that I'll not keep you from trying to use an RD with a threadless mounting bolt like many Simplex RD models....
Hmmmm.... I'm wondering If that wrong sized skewer (way too long) had something to do with that RD hanger's demise........

Don't do any cutting until you take a shot at bending it back. Feel what the steel is doing as you bend it. It'll tell you if it's on the verge of breaking. Then, drop the $10 to buy a tap and fix the threads. Don't cheap out on the most important part of the job.

whatever you do, it's obvious you're gonna need a longer skewer.

+1. Heat gun rather than torch might be more controllable.

I'd try bending it back. Maybe screw a 10x1 bolt + nut into it as tight as you can get it fastened down first,then try bending. Will the 10x1 actually screw in without cross-threading now? But, I don't have a lot of faith that you'll successfully preserve the threads.

And, I'd never sell a frame that I had any belief that the derailleur hanger wasn't 100% up to snuff.

So, with that in mind, it is probably a fixie project.

Or, I might try replacing both dropouts myself (you'll probably have a heck of a time finding just one).

I'd be suprised if it didn't crack while bending back. But that really is the first step- trying to cold bend it back. Heat will further weaken it .. as will bending it back. The least stress the better. A long handled crescent wrench or long Pony clamp would be best to get leverage.

Just to be clear: Jorgensen makes all sorts of clamps in the Pony line. Which type were you thinkin of for this?

I've only had to do minor alignments and used adjustable "crescent" wrenches and "channel-lok" slip joint types. I generally use a large adjustable to hold the upper part of the DO to take the counter torque hoping to minimize the torque on the brazed joints at the stays.

Get out the hacksaw!

I'd bend it but I wouldn't just start with a derailleur alignment tool. I'd take the wheel out first and sort of smash the whole area back down flat within the jaws of a 5" bench vice. Then once bent back down flattish use that tool to attempt to get it straight.

It does look pretty fubared though.

Yes, I was just gonna mention to stabilize the other part of the dropout with a crescent or additional clamp so you can focus the bending pressure better and not affect the rest of the lug. Any clamp with a 2 foot long handle or more will give you more than adequate leverage. The bigger pipe clamps are what I'm talking about. The longer the more leverage- basic physics. Only take a little out of the bend each time. It may break if you try to take the full bend out in one shot.

Excellent advice! This might have a higher rate of success in the end.

I've bent some pretty mangled hangers back. Most dropouts are mild steel even if the frame is cr-mo so that bodes well for bending back. If it snaps or you can't get the hole round enough to re-tap I would cut it off and use a claw adapter. The threads tend to be more of an issue for me than getting the dropout flat again.

Too bad you couldn't somehow put it into a vise and straighten it out by closing the jaws. That way there wouldn't be any pressure other than just there. It would probably be a two person job to tighten the jaws and hold the bike on position.



Sorry. Just re read and see that this idea has already been suggested. Best idea though.

This sounds like the best approach to me.

I like the vise idea best. I think the vise will get it to the point where you can finish the job pounding it between a large hammer and an anvil. At the end you will definitely need to clean it up with a tap and maybe a file. I understand heat has its advantages but I wouldn't know how much to use.

I pictured using three bolts in the final stage. Two behind and one in the front. The bolt in the front would gently push the hanger straight.
Then start wailing on it with your biggest hammer!
No. No hammerin'!
Then get out the hanger straightening tool.

I would also start with the vise, but I'd want something threaded into that hanger to make sure the threads don't get distorted in the straightening/flattening process. Maybe modify a derailleur hanger bolt to be flush with the hanger but have some kind of slot in the middle, so that you can remove it after squeezing.

+2

I'd suggest taking it by Ed Litton's shop in Richmond. He definitely has the tools to ensure it's aligned properly and is fairly reasonable. Call him first to make sure he's there (five-one-oh-two-thuree-seven-one-one-three-two). Barring that I'd go the vice method.

I was going to suggest the vice approach, but other beat me to it. Assess if the hanger is also bent forward or backward. I am very skeptical that you will be able to bend it back without breakage. The threads do look deformed. I don't know how malleable forged DO's are. Good luck and let us know what you did and the results.