Chain snapped help.. :(

[rrarider]

Is a snapped chain a more common occurrence nowadays with the advent of 11 speed blocks and narrower chains? I still ride my 1980s bike with its 6 speed block and Sedis(?) chain. I'd never heard of anyone snapping a chain unless they hadn't refitted a rivet correctly. I was mystified by a report of a bad accident that I'd had 2 years ago and posted on the web; it quoted " A cyclist was riding along the Formby Bypass this morning when the chain on his bike snapped.The chain got caught up in the bike wheel sending the rider over the handle bars smashing his head on the kerb.". I have no memory of the accident and when I picked the bike up from the police station several weeks later the chain and the rest of the bike was OK. If the chain had broken, I doubt it would have ended up in the front wheel causing me to go over the bars.

 

[jefmcg]

If the chain had broken, I doubt it would have ended up in the front wheel causing me to go over the bars.

I imagine a chain in the rear wheel would stop the bike nearly as suddenly, and could still hurl you over the handlebars. Whether that is what happened or not, I can't tell. I have noticed that if I ever read a news account where I have some independent knowledge of the incident, there are always factual errors.

I would hope the police would not repair the bike in case you needed it as evidence of a manufacturing fault that caused the crash. Also, they should have better things to do with their time.

 

[Yellow Saddle]

Is a snapped chain a more common occurrence nowadays with the advent of 11 speed blocks and narrower chains? I still ride my 1980s bike with its 6 speed block and Sedis(?) chain. I'd never heard of anyone snapping a chain unless they hadn't refitted a rivet correctly. I was mystified by a report of a bad accident that I'd had 2 years ago and posted on the web; it quoted " A cyclist was riding along the Formby Bypass this morning when the chain on his bike snapped.The chain got caught up in the bike wheel sending the rider over the handle bars smashing his head on the kerb.". I have no memory of the accident and when I picked the bike up from the police station several weeks later the chain and the rest of the bike was OK. If the chain had broken, I doubt it would have ended up in the front wheel causing me to go over the bars.

No, 11-speed chains will not break easier than say 6-speed chains. The converse is true. With an 11-speed (or 10-speed for that matter) system you have stronger chains because the sideplate holes where the rivets go through are countersunk and the rivet is sunk inside that so that it is flush with the plate. They do this to make the chain narrower. The sideplates have not gone thinner, it is just the space proud of the plates that have shrunk. This countersinking actually makes the chain stronger against breaking open from bending sideways. Note that a chain never "snaps" in the sense that it breaks in tension. It always breaks from bending sideways.
Below 10 speeds, the chains are actually weaker in the bending mode. This is a) because of the rivets which are not countersunk and b) because of the narrower space between sprockets. The narrower the space between the sprockets, the less the chain straddles two sprockets during a change and thus the less chance of it receiving a forceful side pull during a poor shift. Further, non-hyperglide chains have rivets that are only partially peened, usually on two sides. If you look at those pins you'll notice the two opposing cords on the circle. If you look at a hyperglide chain's pin head on, you'll notice that it is peened right around. This looks like a circle on a circle, and is much, much more difficult to pop than other pins.

That description of your (?) accident is completely inaccurate and was made up by the reporter. A chain doesn't snap, it doesn't get caught in the wheel when broken and the reason for the bike coming to a sudden stop (and you keep on travelling) had nothing to do with the chain getting caught in the rear wheel, let alone the front wheel.

 

[Blue Hills]

s. Note that a chain never "snaps" in the sense that it breaks in tension. It always breaks from bending sideways.

That piece of semantics will allow me to ride so much easier. Do you have a handy phrase for this sideways bending breaking? Have you taken this up with the manufacturers, and keen eaters of, brandy snaps?

 

[Yellow Saddle]

That piece of semantics will allow me to ride so much easier. Do you have a handy phrase for this sideways bending breaking? Have you taken this up with the manufacturers, and keen eaters of, brandy snaps?

So glad I could help. But, if you prefer, I could have explained it by using "tensile break" vs "fracture".

Your sarcasm aside, others may or may not find it useful to the understanding of what's happening. Remember that chain companies publish chain strength as pure tensile strength - typically 3 1/2 ton. This figure then confuses people who think they have to push with 3 1/2 ton on the pedals to break a chain and since they've broken a chain and know they don't have such strength. Therefore there must be something wrong with the chain. Fact is, you can break a chain with only body weight.

People tend to equate a rope snapping with a bicycle chain snapping where in fact the two terms are not equal in this special case.

Do let me know how much better you ride now.

 

[Tim Hall]

In my experience not easy at all. I replaced my chain yesterday and after an long time trying I gave up and just drove a rivet out with a chain tool. It was going in the bin anyway.

I believe there is a nack to it, that I don't have.

In lieu of the special pliers, there's the CTC inspired, place the chain on the big ring, with the link sticking out and hit it with a rock method.

 

[Dogtrousers]

Do let me know how much better you ride now.

When I mess up a gear change - especially on a hill - I used to just wince a little bit, and get on with things.

Now I have visions of the links transitioning to tension at the top of the sprocket and the plates pinging off

 

[si_c]

When I mess up a gear change - especially on a hill - I used to just wince a little bit, and get on with things.
Now I have visions of the links transitioning to tension at the top of the sprocket and the plates pinging off

If it helps, I've broken a chain on the flat, starting off after not allowing enough time for a gear change to complete, there was definite pinging as the quick link disintegrated. Had to kick-bike it home.

 

[Dogtrousers]

If it helps, I've broken a chain on the flat, starting off after not allowing enough time for a gear change to complete, there was definite pinging as the quick link disintegrated. Had to kick-bike it home.

Only ever had one chain break on me. That was a big fat five speed chain and the fault was entirely my own (I'd bodged joining it and the plate came loose).

Before I started reading these threads I thought broken chains to be vanishingly unlikely. Now I have reached frantic paranoia and I cycle around with a huge hoard of split links and chain tools just in case. Every klunky gear change brings visions of link plates shearing.

 

[si_c]

Before I started reading these threads I thought broken chains to be vanishingly unlikely. Now I have reached frantic paranoia and I cycle around with a huge hoard of split links and chain tools just in case. Every klunky gear change brings visions of link plates shearing.

I think they are vanishingly rare, but if you cycle a lot you will inevitably encounter it. The key is being prepared for it, if you carry a quicklink and a chain tool, it shouldn't take more than a couple of minutes to be back on the road. It's same as with unexpected deflation incidents, if you're prepared they're no more than a minor annoyance.

 

[rrarider]

Although I'm only familiar with 6 speed set ups and downtube friction levers, I guess that most chain 'breakages' are due to the rivet popping out of the side plate and not because of the plate snapping. With my configuration, I and most other riders of that era would put the bike away with the derailleur springs in a relaxed state. This means that I leave the bike with both levers pushed forward and the chain on the small chain ring and the smallest rear sprocket, leaving the bike in an ill-advised gear setting. It's ill-advised because the chain is at too great an angle compared to the plane of the frame. Setting off for the next ride just requires a couple of down shifts on the rear to be an advised and .easy to pedal. gear setting. Those shifts can be done when the pedalling and lever movement is gentle.

Is this a practice that is still adopted with modern 11 speed indexed set ups? If so, it must mean that the chain angle would be quite large when it's small ring to small sprocket and might account for the chain disintegrations, as the derailleur tries to move?

 

[Yellow Saddle]

Although I'm only familiar with 6 speed set ups and downtube friction levers, I guess that most chain 'breakages' are due to the rivet popping out of the side plate and not because of the plate snapping. With my configuration, I and most other riders of that era would put the bike away with the derailleur springs in a relaxed state. This means that I leave the bike with both levers pushed forward and the chain on the small chain ring and the smallest rear sprocket, leaving the bike in an ill-advised gear setting. It's ill-advised because the chain is at too great an angle compared to the plane of the frame. Setting off for the next ride just requires a couple of down shifts on the rear to be an advised and .easy to pedal. gear setting. Those shifts can be done when the pedalling and lever movement is gentle.

Is this a practice that is still adopted with modern 11 speed indexed set ups? If so, it must mean that the chain angle would be quite large when it's small ring to small sprocket and might account for the chain disintegrations, as the derailleur tries to move?

There is no need to leave the bike in a "relaxed state" as you described. I know it was the practice at the time but it was as a result of a myth that springs go slack and cables stretch when under tension. It isn't true, as zillions of people who park their bikes in any gear will tell you.

But I can see how this practice can lead to nasty starts and broken chains.

 

[suj999]

Quick update, fixed the chain with a quick link. Found it a fairly easy job. Went on a 24 miles Sunday ride with good few off roads paths, no issues.

I did contact Rutland midweek, who said part wasn't covered under warranty.

 

[rovers1875]

Just done the same myself today, I crashed a gear change when caught out by an unexpectedly steep incline The chain came off and got mangled. I hadn't noticed it was damaged and it snapped after another 20 yards. Luckily I was at the top of the hill and I could coast the last two miles downhill back to the car.
I suppose Iv'e been lucky its the first chain I've ever snapped. But I will now carry a couple of replacement links.

 

[mrandmrspoves]

Just done the same myself today, I crashed a gear change when caught out by an unexpectedly steep incline The chain came off and got mangled. I hadn't noticed it was damaged and it snapped after another 20 yards. Luckily I was at the top of the hill and I could coast the last two miles downhill back to the car.
I suppose Iv'e been lucky its the first chain I've ever snapped. But I will now carry a couple of replacement links.

......and a chain tool!