john m flores 

Thanks for all the feedback and advice everyone! I'm just waiting for everyone to agree to how to do it before proceeding. I kid.

I did buy the older (cheaper?) Park Tool and it's waiting for me. I do want to shoot some video of the process but life is getting in the way.

Rest assured, I'll update this thread when I attempt the straightening.

Thanks again.

choddo

because you just added a post to it

grumpus

ITYM "when I achieve the straightening, quickly and easily".

Duragrouch

Exactly. With a bend having yielded and cold worked so may be more resistant to straightening, when trying to bend back, the surrounding metal may give first, and you have an S-bend. This is why, if possible, I prefer flattening with a press, because you are pushing down on the highpoint of the bend, which is the yielded material, exactly where you want to. Sometimes if it is something large I am flattening (like the bottom of a skillet) and the "dish" (curvature) is very local to the center and not evenly distributed, I will use a ring support (backing plate to push on) of smaller diameter, to keep things local, otherwise I may end up with the 3D equivalent of an S bend. On the other hand, if the "dish" is evenly distributed over the skillet bottom, I will support the pan near the outer edge, and then push in the center with a circular wood pad that I have chosen for best effect for the amount of dish. If that makes sense.

grumpus

That pile of scrap by the press tells a story, each piece having been carefully chosen to do a specific job, and some pieces promoted to "press tool".

Kontact 

One assumes that everyone in this thread suggesting straightening the hanger with something other than a hanger straightening tool has never straightened a hanger with a hanger straightening tool.

I bent the hell out of steel Lemond hanger in a crash - bent it back to straight and perfect in 2 minutes with the alignment tool.

What some of you are forgetting is that the tool also protects the shape of the threaded portion of the hanger, preventing it from ovalizing or kinking.

Duragrouch

You may be right. I've never seen one. Ideally, it would have different size washers to adjust to where the bend is, unless they bend pretty reliably in one spot.

Duragrouch

It was especially nice to work in a place with both a press, and a lathe, where in minutes I could fab a press tool to press on the outer race of an 82mm ball bearing inside a wheel knuckle. Not a service garage, but a tier-one auto supplier, I worked in engineering, but it had a full machine shop to fab prototypes. And vehicle lifts. And a solvent parts washer with spray nozzle for cleaning bike parts.

Kontact 

Why would it have washers? Should you be offering an opinion about something you have no experience at all?

FBinNY 

This thread seems to be another example of the BF tendency to make what's simple into something complex.

Steel tabs are straightened every day with moderate force applied via the threaded hole. Anything will serve, though the tool made for the job combines leverage with a gauge to get it square.

Concerns over things like work hardening are overblown, because the low carbon steels used ---- typically 1018, 4130, or similar ---- are not prone to work hardening, and, in any case a single bend like the one shown wouldn't do that.

Straightening the hanger with a wheel securely mounted, (which is SOP to use the gauge) supports the dropout and ensures that bending is localized to the hanger.

Also, it wouldn't matter, even if you were somehow to end up not getting it perfect, because the ONLY thing that matters is that it's square to the plane of the wheel.

So, hoping Nike doesn't sue me, my advice is to cut the BS and "Just do it".

pdlamb

Isn't the bike fixed YET??

Duragrouch

You'll note my qualifying statement. I was asking.

Duragrouch

Umm... I don't like to be an a-hole and throw education out there... but all steels are susceptible to work hardening. It's why low-carbon and no-alloy steel can make piano wire that is well over 300ksi strength, about 10X the steel's original strength, purely due to the work hardening of drawing the metal multiple times through a die. It's why hard swords and knives were possible before alloy steels. Now, that derailleur hanger may not have gotten work hardened at the bend if not too severe. But all steels, in fact most metals, will work harden. Brass work hardens, which is why, firearm cartridge cases, after shooting and reloading several times (which involves "resizing" the case in a die), need to have the case necks annealed, so they maintain sufficient ductility for a proper bullet crimp.

High-alloy steels, such as "stainless" steels, same thing, but additional issue: All you have to do is get them heated above the hardening temperature, and they will harden simply by air cooling, they don't need to be quenched, as the alloys increase the "hardenability". If you've ever drilled through a piece of stainless, didn't keep it cool, saw just the tiniest spark at the drilling point, and suddenly it's hard as glass, you need to go find a tungsten carbide-tipped or boron steel drill to finish the job.

By the way, non-magnetic stainless steel, when you cold work it, becomes magnetic (will attract a magnet, not is magnetic itself), increasing with the amount of cold work. Check the magnetic attraction on a tri-ply pot (that does not have an intended magnetic bottom for induction burner use), at the bottom, at the bend to the sides, and at the rim.

FBinNY 

Yes, and NO.

I chose my words carefully when I said "not prone to work hardening", and I stand by that. Yes, all steels work harden, and people like myself that work with steel are aware of and deal with it accordingly. But it's a question of degree, with different grades work hardening more or less than others. In any case, a single gentle bend like this, in the steels used in that application would not be problematic.

Education is good, but you have to apply it to the task at hand, and throwing out tons of non-relevant info isn't constructive.

BTW piano wire is NOT a low carbon grade. Typically it's 1080, which is a high carbon grade. And as you note, is worked greatly by multiple passes to bring it to that strength.

Duragrouch

No worries, and I appreciate the info. By the way, are you by chance familiar with a website called knifesteelnerds.com , authored by a metallurgist named Larrin Thomas? It's an exceptional website, in my opinion. I particularly enjoyed his story on the creation of MagnaCut, which is a premium powder-metallurgy steel, combining excellent hardness with superb toughness and corrosion resistance. However, it's an order of magnitude more expensive, due to the PM process. I thought one day, "What's the best ingot steel?" (non PM process), and he has a great article, "What is the best budget knife steel?", which has, among other criteria, conventional ingot process. That article indicated 14C28N as a superb bargain steel, a standout in combination of hardness and toughness, vastly superior to X50Cr15MoV of all my kitchen knives (which were a premium steel perhaps 40 years ago, but not now). Anyway, sounds like you might like the website. All the best.

BTinNYC 

john m flores
JUST BEND THE S.O.B. ALREADY.

Kontact 

You didn't answer my question: What washers were you talking about?


As for this statement - swords weren't created by work hardening iron, they were created by making steel by alloying the iron with carbon and then heat treating that high carbon steel.

All metals work harden - that's how you break them by bending back and forth enough times. But otherwise can be very different - you anneal brass by quenching it - the opposite of steel.

wheelreason

Are we straightening a drop out or trying to land a probe on an asteroid? Come on now, screw the tool in there and have at it...

curbtender

The question is, "How many mechanics does it take to screw in a derailleur alignment tool?"

wheelreason

Skad sa ci mechanicy?...

smd4

Well...his drivetrain sort of looks like the surface of an asteroid...

Camilo

Um, have you ever read a bikeforums thread?

wheelreason

Besides for entertaintment value?, No....

Duragrouch

Washers: Non-existent ones. I suggested, did not say for certain, that it might be ideal to adjust the radius at which the tool functioned (with different diameter washers in contact with the derailleur hanger), in case derailleur hangers bent at different places. I have not seen the tool. Others (perhaps you, I don't recall) here have said such washers, at different diameters, are not necessary. I accept their statement.

Swords: From wiki: "Early Iron Age swords were significantly different from later steel swords. They were work-hardened, rather than quench-hardened."

Brass: Yes, I know; Place the cartridge standing up in a pan of water, depth up to where you don't want any annealing, heat the top (mouth) of the cartridge with a propane torch to temperature, then tip it over into the water. Watched my dad do it hundreds of times when I was young. I did everything else with regard to reloading match ammo, just never that, dad handled the torch while I did other processes. When I competed when older, the government loaned me a rifle and gave me all the ammo.

FBinNY 

To nail it home.....

No washer is needed because the wheel's mounting faces serves that purpose.

Also consider the nature of the force applied. It's not straight across as would be with a press, but a twisting force applied as a torque, which helps move the hanger in an arc.

In any case, those familiar with bike repair know that this job is very common and easily done (in steel) with no complications.