Sy Reene

I've done it with my Ti Merlin hangar. Not that big a deal. As mentioned do small things, test and continue. Don't go for a homerun on the first attempt.

Trakhak

How did the bending operation turn out?

Polaris OBark

I have two steel bikes like this. I still worry.

veganbikes

It is to a point but it is just a good idea to do that just in case it is not true.

Onions as tempura is delicious love it. The alcohol works quite well.

FBinNY 

One of the first and most important lessons one learns as a manufacturer is how to set tolerances and avoid pointless (expensive) precision.

Doubtless, one would want to avoid using a badly untrue wheel as a reference. However any rideable wheel -- passes through brake shoes without rubbing -- is true enough to align the RD to well within half a degree.

So, as a practical matter, one needn't obsess about indicating anywhere on the wheel.

veganbikes

Ok fair dinkum but I will still do it the way I was taught because I do value accuracy and precision.

Kai Winters

NOPE NOPE NOPETY NOPE ! ! !
If you don't have the proper rear derailleur hanger alignment tool then either buy one or bring it to a shop...or you certainly can just kludge it using a pair of vice grips, etc. as grumpus suggests and hope for the best...it's not my bike so I don't have a monkey in this circus...

FBinNY 

No problem. I'm not invested in what people opt to do, especially knowledgeable people.

OTOH one of my self appointed roles on this forum is to be a counterweight offsetting the tendency to obsessively paint lilies.

FBinNY 

Doing emergency repairs in the field, I'd put a hex key into the RD mounting bolt and muscle it home by eye, adding the RD cage as my guide.

But, yes, a vice grip would be my absolutely last option. If you're not strong enough to move it with a hex key, consider that the wheel's axle has thr same thread.

zandoval 

GREAT! that changes everything.

Then after getting it as close as possible use the Park Tool...

Of course John, You know this...

FBinNY 

Why are people making a simple job complicated. There's no need to use a vise or do the job in 2 or more steps.

Steel's yield strength is a fixed property, so the same force is needed for this as to tweak the hanger on a newly built frame.

If the tool is strong enough for that (as it obviously is), then it's strong enough to horse this hanger home.

Duragrouch

Two points.

First, the hanger straightening tool may work, but I've staightened a lot of stuff, and if I had my choice, I would pull the wheel off, lay the inboard side of the hanger on something flat, and push on the outboard side with a hydraulic press, it's a more foolproof way of doing things, you won't overshoot, and due to springback, if that doesn't flatten it, put appropriate spacer under the inboard end and press again.

Regarding the yield strength of steel staying constant, no it doesn't, not after cold working, and yielding is cold working. (For not a large bend, perhaps not too bad.) Take a steel paper clip and bend it, now try to straighten it, where you bent it will be harder to bend back to straighten, as it has been cold worked. Before alloy steels, cold working was how you made a strong sword or knife from low grade steel. That is why "piano wire", guitar strings, et al, have typical tensile strengths of 380,000-425,000 PSI (extremely high strength), from steel (iron with carefully controlled carbon content) with no alloys, no heat treatment, because of the cold working (via drawing the wire through a die). What DOES stay constant is the elastic stiffness of the steel, the Young's Modulus, that does not change within families of materials, even as yield and ultimate strength changes (with a few rare exceptions of newer exotic metal alloys).

Kai Winters

Sure...if you're in the field and it's an emergency 'quick fix' to get back...that's not the discussion...but again, it's not my bike so it's just a curiosity to me as to how it is 'fixed'...

john m flores 

Which highway?

grumpus

He has the alignment tool. From the photos the hanger looks to have been pulled back and twisted in, which is more than I'd expect the tool to cope with, so I suggested getting it in something like the right orientation before setting it with the tool. There's no way the tool could manage to close the dropout, if that is indeed required. Even if it just needs pulling out, the tool is acting on the end of the hanger, but the main distortion appears to be at the top of the hanger - perhaps not a crucial difference, but it could end up S-shaped rather than flat.

grumpus

There's no need to go there - measure below the chain stay, behind the seat stay and mid-way between those two points.

curbtender

Picked up the tool locally and it gets used all the time. I've moved some pretty tweaked ends. Don't think he is going to have a problem with that.

roadcrankr

This. Kai went all nopity nope on you, when you merely suggested starting the fix with another tool.
Only difference for me might involve plunking a properly spaced hub in there to keep everything else stationary.
Hard to tell if the hanger distorts in other directions. Could present Mr Flores with more problems.

Kai Winters

A rear derailleur hanger alignment tool is designed to align a hanger in a variety of planes.
I've...carefully and slowly...re-aligned bent and twisted hangers bringing them back into the exact and correct position. Especially so on a steel hanger that is part of the frame/dropout. I prefer aligning steel hangers as steel is far more moveable and far more forgiving than an aluminum hanger especially some of the hangers I have to align that are so cut out...for no good reason...the metal is thin and far more prone to snapping than wonderful steel whose molecules love being manipulated.
I do not ever recommend using the incorrect tool unless absolutely necessary because using a tool such as 'vice grips' with all its lovely teeth is going to mar the metal, regardless of type, same with pliers, and even adjustable wrenches though and adjustable wrench is less likely but I also have to take into the consideration the person doing the 'manipulating'. In general they are clueless and cause far more harm and damage than if they just left it alone.

You want to learn how to do this stuff correctly and have the correct tools? Buy a used bike...cheap...doesn't matter what kind...and practice on it using YouTube videos as a guide. Or better yet hire a reputable shop mechanic to teach you basic service and maintenance skills during the winter months when customers are few and time is more available.

70sSanO

An alignment tool is the best way to go. That said the accuracy of bending a steel hanger back is "somewhat" dependent on the number of speeds you are running.

Some years ago I used a precision square in the dropouts and an 18" crescent wrench to straighten a bent hanger. I think the use of a precision square over a Harbor Freight square is the key, at least in one's own mind.

But I'm running an 8 speed cassette and the Centeron probably picks up enough of the visual out-of-tolerance.

If I were doing it today, I'd get an alignment tool. I have a lot more tools now than I used to have, and many only get occasional use. I somehow survived my ham fisted era.

John

grumpus

It would be good to check the dropout alignment once the hanger is back where it should be.

SurferRosa

Still knocking the mud off.

shelbyfv

Bump. Could be done in the time it takes to read this thread. Maybe OP is preparing a video for us.

RB1-luvr

I had a cx race bike that was mis-shifting recently (replaceable aluminum hanger on cf frame). I complained about it to my bud in the parking lot at a race. He took my bike and said, "I'll be right back". He came back three minutes later with it fixed. He had the tool in his car. So why is this thread still going?

curbtender

Because you can't start a thread with a before picture and end it without an after?