Replaceable Derailer Hanger gets Replaced

Replaceable derailer hangers are engineered to break, to spare the derailer, and this one did in an S&S travel case. Can’t imagine the forces within the case to do that, but break it did. Sheared right off. Discovered this back home from the Mobile Social Worldwide.


Replaceable derailleur hanger Besides dings and an ever-developing travel patina, a broken derailer hanger is a new occurence. This was on the Dahon Mu SL we took with us. I suspect it’s because the wheels and tires weren’t there to protect it. The Dahon isn’t intended to break down fully like an S&S – you fold it in 1/2 into a large case. With the recent crack down on luggage by the airlines and a very long trip, we packed the Dahons in cases I knew would pass through baggage.

Cost to repair is about $15.00 USD.


Pun not intended, I’m torn about replaceable hangers.  They may bend or break away to protect the frame, but they also have to be weaker than the frame to actually work, so they are going to seem like they “do their job” a lot.

On the other hand, a stiffer and stronger builtin hanger might prevent that damage in the first place.  Don’t we spend more time shifting than crashing?  In a bad crash, what are the odds of tweaking *just the hanger* anyway?

Yes indeed—what possibly could’ve happen in a travel case other than a big hit and sudden jolt? So it’s not like a stump would grab the derailer in there. I did not have a camera in the case, but though, “huh, wonder if that was some defective hanger.” Or if it had been bent and weakened over time. Trek, finally after years of complaints added a replaceable hanger to their Madones. If you bent your hanger on the Trek, beyond what a hanger tool can fix, was a trip back to Waterloo.

There are plenty of opportunities for either argument to be wrong, that’s why I’m split.

At $15/pop, the risk of having to replace a hanger versus the entire frame may not even pay off.

Like a helmet, I guess you’re lucky that the hanger gave way and the bike took *only one* big hit?

Whatever the Trek hangers gave away in convenience was put back with stout 7mm (I measured) dropouts.  If that hanger doesn’t hold up in a crash, I have a feeling it won’t be the only reason that frame returns to America’s Dairyland.

So here is the solution to possible damage to the hanger while traveling with the bike.  Take the derailleur off.  It sticks out a couple inches typically and is the closest part to the top of the case and regardless of how hard the case is it will flex due to size of the case unless it is a metal case.  Leave it connected to the cable and simply zip tie it to the chainstay.  Putting it back on is all of a 30 second exercise. Work wonders and saves you $15. 

As to the argument around to be or not to be….hangers are great unless the manufacturer makes them too soft which is common as they want it to shear well before the frame takes the load.  You can typically buy aftermarket ones that are a bit better than the stock ones but they will still bend before the frame does and that is a good thing.  Sounds like Trek is one of the few that makes a worthy hanger.  Good for them.  Always carry a spare hanger and it breaking is not much of an issue as it is an easy trailside repair.

That’s correct and do that with the S&S bikes. Smaller, 20 inch wheels bikes are meant to fold in seconds. Removing the derailer is usually not required.

argh, Byron! I suspected that you hadn’t pulled the derailleur before putting the bike into the S&S case.  sorry to break it to you, but derailleurs and hangers are engineered for riding first, not packing. 20” wheel or no, the width is the primary concern when packing, and those dahons are exactly the same width at the rear as any road bike. DEMOUNT THE DERAILLEUR WHEN YOU PACK.

and also, apologies to anyone misled, but $15 is a BRO DEAL, not what I charge to just any schmuck off the streets.  you plebes are gonna pay me $25 (depending on the hanger maybe $35).  don’t like it? suck it! it’s called retail.

as for people thinking that replaceable hangers are a bad thing, you probably aren’t working in a bike shop.  i see all kinds of fucked up derailleurs come in, and though it’s a hassle to order some oddball hanger (uh hem, Byron), it’s better than telling people that their bike is ruined.  it is very true that some hangers are overly soft, but i view it as a necessary evil. 

what are the odds that just a hanger would be bent?  well, i think everyone can agree that ripped handlebar wrap is easily dealt with, but hangers get bent all the time in my experience at a shop.  maybe they get bent because the replaceable hanger is soft, but as mechanic I’ll straighten a replaceable hanger but refuse to touch a nonreplaceable hanger on an alloy or carbon frame. if the replaceable hanger breaks, i can order a new one, but i want the customer to sign off on the work order before i risk snapping a nonreplaceable hanger off of a frame. 

and don’t go blaming it on alloy and carbon frames…. i see twisted hangers on steel frames all the time.  you should see what happens to a steel dropout when the derailleur gets twisted into the rear wheel. it ain’t just the hanger, but the whole dropout that gets warped. a replaceable hanger will isolate the damage to just the hanger module. 

over the years, i’ve developed a special technique for repairing steel dropouts (from watching Bill Davidson), and let’s just say that it’s an operation i don’t let the owner see.  it is, however, great for stress relief (mine).

That was a mistake yes, but note that the other Dahon suffered no damage and that was an educated decisions to travel with them and break them down as little as possible. I travel with several different bikes and the Brompton has flown in the S&S case just fine—that’s because it has the wheels and tires attached, protecting the important bits. The Dahons did not do well in the S&S and that was a good test I’m reporting back to Dahon—contributing to the problems were V-brakes, flat-bar parts, and long-cage derailers.  All those protruding, elongated shapes are prone to getting beat up v. say a road derailer or and STI. Dahon’s Airporter case is being updated and I’m suggesting they make it more compact and skinny-cyclist-forearm friendly, with better casters.

On a trip that long with many cities and [cramped hotel rooms](, the Dahons were a struggle to put together—I got it down by the time we got back. The problem is the swooping boom shape doesn’t provide anything to support itself until you get it mostly back together. So you’re holding it one hand, putting parts on it, trying not to foul the carpet with chain grease and adjusting stupid V brakes, which I will argue are the worst brake design ever released.

As I said above, so I’m clear, Dahons aren’t intended to go into S&S cases and I did that as a test and to ensure I was getting through airport check in without being charged.

Really interesting test - I’ve been thinking about buying a ‘08 Dahon Cadenza 8 (with the afline hub) and was hoping that I might be able to squeeze it into an S&S case, but I need to get my hands on one and see if it’s actually possible first.

Definitely try it out—S&S makes a larger case and you’ll want to take more precautions than I did and should work fine. For some perspective, I’ve travel all over—Mark has traveled more—with an S&S bike in a case and no major damage. You will incur [scratches and dings](

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