phatjo911

I can't shift into the highest (easiest) gear without my derailleur going into the spokes.

Here's a pic.



Do I need a new one?
I'm pretty sure it's bent... How much would it cost for a new one?

Also, I can't seem to thread the barrel adjuster back into the RD body. The whole screw came out 'cause I unscrewed it too much, and now it doesn't want to screw back in. Any ideas?

JohnDThompson 

It sure looks bent. Take it to a shop; they may be able to straighten it for you at trivial cost.

cny-bikeman

Of course it is bent - pulleys should be parallel vertically with the cogs and frame centerline. That's a removable hanger by the looks of it, so either straightening or replacement will fix the problem. Do NOT let anyone "eyeball" it on a 9 block - the proper alignment guage/tool is necessary to do a proper job.

My eye tells me it's possible that the derailleur is also bent/twisted. If true (and it's likely if the derailleur actually did dump into the spokes) that's almost impossible to fix back to spec. Not worth the risk of trying and finding out later it did not work - if bent replace it.

DieselDan

That is very bent. May need to be replaced....

phatjo911

I'm pretty sure the derailleur isn't bent itself.

It is a removable hanger and I think I will take the whole thing off tomorrow.

I will probably try to straighten the hanger itself by pressing it in a clamp between two pieces of wood.
If it doesn't work, then I'll just buy a new one, but it can't hurt to try, right? (since it's toast anyway)

wtandem

I doubt you will be able to do it with two pieces of wood. The hanger is small. You need a long guide tool ( see the Park WEB site for their derailler hanger tool ). It's a 10 minute job with the right tool. Either go to a shop or if you have a kid like mine who crashed often, buy the tool.

cny-bikeman

The problem is that the hanger has to be parallel to the cogs both vertically and horizontally. That is critical with a narrowly spaced 9 block. Yes, it can hurt to try. If you distort the thread when you straighten it (which is possible when there is nothing screwed into the mounting hole) you will have more of a mess and will then have to replace the hanger anyway.

davidad

If you don't have the tool and have another back wheel you can true the hanger. Remove the der. and thread the extra wheel (it has the same thread size) into the hanger. Using the extra wheel as a lever bend the hanger until it is parallel with the wheel on the bike.
If it happens again replace the hanger. Aluminum does not have a long fatigue life.

Retro Grouch 

Might as well buy another hanger now. In fact, if it was my bike, I'd get 2. Hangers aren't too expensive but waiting for a replacement to arrive is a PITA.

BCRider

A trick an airplane metal beater taught me a few years ago for stuff like this.

1. Use a candle or cigarette lighter to blacken the part with soot until it's quite black.
2. Fire up a propane torch and heat the part until it's hot enough that it burns away the blackening on it's own.
3. Once the color is back to silver wave it around in the air or dunk in some water to cool it.
4. It is now annealed and will stay that way until you bend it some more or in the case of heat treated alloy for about a day or two.

Once it's annealed flatten it as best you can with your home tools. And no, blocks of wood are too soft to do the job. You'll need something else along with some care since it will want to bend at the holes a lot sooner than at the part between where it's actually bent now. Once you get it more or less flat mount it to the frame and take it in for the LBS guy to use the alignment tool for the final truing.

If you use davidad's method with the other wheel be sure it's one where the axle is long enough to thread all the way through the hanger. All the quick release wheels I've got or seen have too small a threaded section to work without risking tearing out the threading in an alloy hanger like this.

For the rest of you this annealing trick actually works very well. I was sceptical at first but I had two old bent motorcycle clutch levers that I could not bring myself to toss out. I blackened one and heated it as instructed until it was silver again. I was able to straighten and use both of them again. Normally the forged levers used on motorbikes are a "one hit wonder" and the generally accepted truth is that you only get one bend and then they break when trying to bend back. They're right too as I'd had previous lever snap even from trying to bend back only slight damage. But with the annealing process I was able to straighten one moderately damaged lever and one that looked like a freakin' pretzel! So keep it in mind for some time when you have a bent forged part that is toast anyway.

fietsbob

Indexing is fussy about derailleur hanger plane being parallel to the centerline, of the bike
so if you don't check the alignment afterwards, even after a successful straightening procedure,
the indexing may still not click in .

even a new part needs the alignment checked once its on the bike.

canopus 

Good grief people. Its a 15 or 20 dollar part. Replace the hanger. Why risk it fatiguing and breaking or bending again inserting your RD into the rear wheel risking you more money, your frame, or your life (depending on where it fails while your riding)

Deanster04

+1
Also, have the LBS (a good one) check the straightness of the unit after replacement to make sure your attachment base isn't bent as well. They have a tool that will do the job simply and cheaply (and buy the part from the LBS even if it costs more). The LBS will do the check very cheaply for you...and if no charge find out what kind of beer the person likes. Good luck.

moose8

I'm totally for not screwing around and just replacing it - it sucked when my derailler caught in my spokes because the hanger was likely bent from a crash.

ScrubJ

Hanger is much less expensive that rear wheel+hanger+derailleur, replace the hanger and have it checked at your LBS