Friday, February 27, 2009

Thoughts on derailleur hangers

Mmm. I don't know if you guys can handle this much excitement on a Friday, if not, come back tomorrow for a recipe or something.

People ask me a lot about putting dropouts with a replaceable derailleur hanger on their bikes. I usually tell them something snide about how I wouldn't know, since I *only* ride rigid 29" singlespeeds with bullhorns and a pink chain to match my ironic 80's style American Apparel t-shirt. They're usually so humbled by my glory that they just give up at that point, but today I'm feeling generous, so here we go.

My feeling is this: I've built hundreds of steel frames, and I've had zero (nada, zip, zilch) come back for hanger repairs. Those hangers are burly - 1/4" plate steel doesn't bend easily. You'll shred that derailleur long before you do much to the hanger. And they're really easy to bend back with a $25 tool (Park DAG-1) if you do manage to bend them.

Replaceable hangers are a great idea for aluminum bikes, where the hanger is A) weaker to begin with, and B) can't be cut off and re-welded without spending a fortune re-heat treating the frame. But I don't build aluminum bikes, eh? I'm happy to do a replaceable hanger dropout (Paragon makes a nice one that I normally use when my logic-dropping fails to sway someone), but in my experience, they break all the time and have to be constantly replaced. Given that the replacement hangers are $15 or so, it's not a great investment IMO. Sure, you can carry a spare hanger around in your pack, which you can't do with a non-replaceable one, but honestly, it's not that hard to ghetto-singlespeedify your bike to get home anyway if you really need to.

7 comments:

Anonymous said...

I must have bad luck--I've bent the hanger on my steel bike twice (I seem to wipe out just right/wrong). I have used the park tool to bend it back but I wonder, does it compromise the strength of the steel/hanger there? If I bend it once (or twice) am I more prone to bending it again?
Thanks

MikeQ said...

Steel is real... can be bent back with monkey grips. Aluminium is not, and I now need new parts for the ventana already...

Dan O said...

Steel hangers seem to be super durable. I've only bent one in way too many years of riding. Tweaked it back into shape with a giant adjustable wench. Crude, but works.

We used the giant adjustable wrench technique when I worked in a shop during the '80s. The wrench could also be used to assist with unruly customers as needed.

I've been following your blog for bit - nice job.

Walt said...

Anon -

It will weaken the hanger every time you bend it back, yes. Think of bending a paper clip back and forth over and over - it will eventually snap. In this case, you're dealing with something a bit stronger than a paperclip, though, so it will take a LOT of rebending to break it.

Dan O -

Mmm. Giant adjustable wrench. I'm a fan of that technique too. I have to admit that 9 and 10 speed setups don't respond quite as well to it, though. Give me a nice 7 speed setup and I can wrench that hanger straight enough in no time!

Brandon Ives said...

I've seen a good number of totally dead steel hangers over the years, but they can still be fixed. A nice M10 nut can be welded in place of the cut off old hanger. A little work with a grinder and file and some touch-up paint and it's good as new.

Between that method and Wheels Manufacturing's threaded inserts there's absolutely no reason for a replaceable hanger on a steel frame.

Wayne Smith said...

My favorite "ghetto" technique is to use a 5mm in the der. bolt for some extra torque and an extra vantage point to get that tricky sucker just where it needs to be.

kw said...

Was going to ask you about this several months ago. (After a stick wrapped around the derailleur and bent the hanger at an odd angle.) Guessed that steel was more forgiving and the LBS (doing the repair) was better than most. No worries since.