Read Derailleur has snapped off

For discussions about bikes and equipment.
keyboardmonkey
Posts: 1120
Joined: 1 Dec 2009, 5:05pm
Location: Yorkshire

Re: Read Derailleur has snapped off

Post by keyboardmonkey »

I once ordered a spare rear mech hanger from the shop I’d bought my bike from. It was supposed to be for a Giant TCR and they ordered me one for a Giant Defy. Get the bits off your bike, take them in to Halfords and tell them the make, model and year of your bike to identify the correct hanger. Buy two.
NickJP
Posts: 793
Joined: 24 Sep 2018, 7:11pm
Location: Canberra, OZ

Re: Read Derailleur has snapped off

Post by NickJP »

Since the advent of replaceable derailleur hangers, when I buy a frame that has a replaceable hanger, I always try to buy a spare hanger for it at the same time. The Open frame that I bought a few years ago came as standard with a spare hanger - more manufacturers should follow suit - with the last frame I purchased, the spare hanger for it was an additional £25.
JohnMorgan
Posts: 111
Joined: 9 Jun 2022, 7:19pm

Re: Read Derailleur has snapped off

Post by JohnMorgan »

Apologies for off topic.
I had a letter for a free eye test, took it in to Vision Express, the receptionist told me I definitely needed glasses - the letter was from Specsavers . . .
User avatar
Cugel
Posts: 5430
Joined: 13 Nov 2017, 11:14am

Re: Read Derailleur has snapped off

Post by Cugel »

NickJP wrote: 14 Aug 2022, 12:27am Since the advent of replaceable derailleur hangers, when I buy a frame that has a replaceable hanger, I always try to buy a spare hanger for it at the same time. The Open frame that I bought a few years ago came as standard with a spare hanger - more manufacturers should follow suit - with the last frame I purchased, the spare hanger for it was an additional £25.
Agreed.

I have two identical frames configured as bikes of different purposes via the bits and pieces. I bought one gear hanger as it will fit either. Of course, sod's law means that it's always going to be in the tool bottle on the other bike at home if & when I snaps the gear hanger of the bike I'm on. Perhaps such spares should be built in to the frame by the manufacturer?

Cugel
“Practical men who believe themselves to be quite exempt from any intellectual influence are usually the slaves of some defunct economist”.
John Maynard Keynes
francovendee
Posts: 3145
Joined: 5 May 2009, 6:32am

Re: Read Derailleur has snapped off

Post by francovendee »

I've bent a derailleur hanger on a few occasions but never had one snap or seen it happen.
I'd guess it had a flaw in the metal from new.
I think this was just bad luck.
Your bike would end up being megga heavy if you took a replacement part for everything that rarely breaks.
rareposter
Posts: 1964
Joined: 27 Aug 2014, 2:40pm

Re: Read Derailleur has snapped off

Post by rareposter »

francovendee wrote: 14 Aug 2022, 8:05am Your bike would end up being megga heavy if you took a replacement part for everything that rarely breaks.
But a rear mech hanger is supposed to break - it's the cheap sacrificial part that protects the very expensive frame and the quite expensive rear mech from terminal damage. It's small, lightweight and can be kept indefinitely in a saddle bag.

I'd actually say it is the one essential bit of kit for any rider to have with them at all times. You can walk into any bike shop and buy a tube or a chain, most riders passing by are likely to be able to lend you a pump or an allen key if you don't have any of those but no-one will ever have the exact hanger you need for your bike.

It should be the required spare at all times - if you've got it a broken hanger can be fixed in 15 mins or so, I've done it roadside many times when ride-leading. If you don't have it, it is a ride-ending disaster.
I've bent a derailleur hanger on a few occasions but never had one snap or seen it happen.
I'd guess it had a flaw in the metal from new.
After punctures, I'd say it's the second most common mechanical on events where I've been ride leading. A lot of that is down to the relative "beginner" nature of some of the riders, hamfisted / ill-advised gear changes but sometimes also crashes.
I wouldn't say it had a flaw in the metal at all - it's designed to break and if it's taken a few knocks, a load of force from a poor gear change, been bumped around in transit, been slammed with regular wheel changes or been incorrectly installed in the first place etc, it'll go eventually.
Mike Sales
Posts: 7860
Joined: 7 Mar 2009, 3:31pm

Re: Read Derailleur has snapped off

Post by Mike Sales »

rareposter wrote: 14 Aug 2022, 9:46am
I wouldn't say it had a flaw in the metal at all - it's designed to break and if it's taken a few knocks, a load of force from a poor gear change, been bumped around in transit, been slammed with regular wheel changes or been incorrectly installed in the first place etc, it'll go eventually.
I hate seeing a bike laid down on its right side, especially by chilodren. If the dreailleur gets bent it will hit the spokes next time bottom gear is selected. Doesn't do an SA indicator chain much good either.
It's the same the whole world over
It's the poor what gets the blame
It's the rich what gets the pleasure
Isn't it a blooming shame?
User avatar
Cugel
Posts: 5430
Joined: 13 Nov 2017, 11:14am

Re: Read Derailleur has snapped off

Post by Cugel »

francovendee wrote: 14 Aug 2022, 8:05am I've bent a derailleur hanger on a few occasions but never had one snap or seen it happen.
I'd guess it had a flaw in the metal from new.
I think this was just bad luck.
Your bike would end up being megga heavy if you took a replacement part for everything that rarely breaks.
But some spares and tools are light in weight whilst others ......

Long, long ago, before the roads were tarmacked and when no shops or cafes opened on Sundays, I went out with the local CTC runs. More than one of the greenspot jacketed fellows with a Large Yellow Cape tied to their bike also had a ginormous saddlebag (Carradice, naturally) full to the brim with spares of every sort - chain, tyre(s) & tubes, spokes, two Q/R skewers et al. They also tended to carry Large Tools, even up to and including a 2lb pedal spanner or a lump hammer for the cotter pins!

The hills were a problem for them, of course. Those saddlebags also had the sunday Dinner in them, as well as the tools and unassembled spare bike. Well, the uphills - the downhills provided huge momentum, which often tested the Mafac and Weinmann centre-pull brakes to their limit and beyond.

These days we have feathery multi-tools that can perform miracles of bicycle surgery. And quick-links. And derailleur hangers. Mind, I draw the line at them CO2 cartridges. I've seen many a lad increase global warming with one or more o' them, as they fail to connect the gubbins to their valve properly and the gas hisses everywhere but into their tyre. :-)

Cugel, dreading my first taxi-of-shame. (May it never be required, unless its a hearse).
“Practical men who believe themselves to be quite exempt from any intellectual influence are usually the slaves of some defunct economist”.
John Maynard Keynes
francovendee
Posts: 3145
Joined: 5 May 2009, 6:32am

Re: Read Derailleur has snapped off

Post by francovendee »

rareposter wrote: 14 Aug 2022, 9:46am
francovendee wrote: 14 Aug 2022, 8:05am Your bike would end up being megga heavy if you took a replacement part for everything that rarely breaks.
But a rear mech hanger is supposed to break - it's the cheap sacrificial part that protects the very expensive frame and the quite expensive rear mech from terminal damage. It's small, lightweight and can be kept indefinitely in a saddle bag.

I'd actually say it is the one essential bit of kit for any rider to have with them at all times. You can walk into any bike shop and buy a tube or a chain, most riders passing by are likely to be able to lend you a pump or an allen key if you don't have any of those but no-one will ever have the exact hanger you need for your bike.

It should be the required spare at all times - if you've got it a broken hanger can be fixed in 15 mins or so, I've done it roadside many times when ride-leading. If you don't have it, it is a ride-ending disaster.
I've bent a derailleur hanger on a few occasions but never had one snap or seen it happen.
I'd guess it had a flaw in the metal from new.
After punctures, I'd say it's the second most common mechanical on events where I've been ride leading. A lot of that is down to the relative "beginner" nature of some of the riders, hamfisted / ill-advised gear changes but sometimes also crashes.
I wouldn't say it had a flaw in the metal at all - it's designed to break and if it's taken a few knocks, a load of force from a poor gear change, been bumped around in transit, been slammed with regular wheel changes or been incorrectly installed in the first place etc, it'll go eventually.
I repeat,
I've never known one break but plenty bend, this is what they are designed to do. This normally won't stop the bike working. Different matter if the derailleur gets bent but I wouldn't carry a spare derailleur.
I've failed only twice to finish a ride, both times a catastrophic tyre failure. Perhaps I should carry a spare tyre.
If I were doing a world tour then possibly I'd take a spare hanger but on day or short tours then no.
It's quite possible to straighten a bent one by the roadside by the way.
Stoneybatter
Posts: 43
Joined: 24 Jul 2022, 6:20pm

Re: Read Derailleur has snapped off

Post by Stoneybatter »

.
Last edited by Stoneybatter on 20 Aug 2022, 1:24pm, edited 1 time in total.
User avatar
Sum
Posts: 323
Joined: 17 Jul 2010, 9:13am

Re: Read Derailleur has snapped off

Post by Sum »

Interesting. That s-shaped hanger you mention sounds like an adapter claw. They're supposed to fit horizontal dropouts:-
https://www.sheldonbrown.com/gloss_aa-l.html#adaptor

The replaceable mech hanger is designed to protect the frame that might otherwise be irreparably damaged if (for example) the chain or rear mech fouls on something. An aluminium or carbon fibre frame needs a replaceable hanger that will break before the frame does, whereas steel frames may get away with a rear dropout with built-in hanger.

The replaceable mech hangers on my bikes are reasonably substantial parts, but they still break when required. I've had to straighten the odd one when I bent it and it still works. On the other hand I've also had a couple snap when some 'debris' got caught up in the chain and tried to pass through the rear mech cage with it. Thankfully the frame wasn't too damaged, nor was the rear wheel. If the mech hanger hadn't broken when it did, I'm sure the frame would have been written off.
Stoneybatter
Posts: 43
Joined: 24 Jul 2022, 6:20pm

Re: Read Derailleur has snapped off

Post by Stoneybatter »

.
Last edited by Stoneybatter on 20 Aug 2022, 1:24pm, edited 1 time in total.
User avatar
Sum
Posts: 323
Joined: 17 Jul 2010, 9:13am

Re: Read Derailleur has snapped off

Post by Sum »

Even the built-in hangers on steel frames can be bent, sometimes damaging the drop-out as well and requiring a frame builder to fix. If that's of a concern then I'd suggest an internal gear hub, particularly if you have horizontal drop-outs.

However in my case, the reality is that mech hanger breakages seem to be rare. The ones I had were perhaps exacerbated by having a tendency to ride through the local woods on the way to work, which is more pleasant than taking the main road. When the mech hanger broke I simply replaced it myself and all was good, so it's not really an issue for me.
scottg
Posts: 1217
Joined: 10 Jan 2008, 8:44pm
Location: Highland Heights Kentucky,, USA

Re: Read Derailleur has snapped off

Post by scottg »

Emergency hangers are used by mountain bikers.

https://wheelsmfg.com/emergency-hanger.html
+++++++++++++++++++++++++
Deutsche Luftschiffahrts-AG
+++++++++++++++++++++++++
Post Reply