My chain broke at 1 000km

MozBiker

I just had a funny thing happen. I replaced my chain 1035km ago... And today as I was I in the middle of a sprint(not full speed yet) the chain broke and I came off and lost some skin and got pretty banged up.

Am I correct in saying that 1 000km is too soon for a new chain to break? It is not a cheap junk chain. It is an expensive one from a very reputable brand. So I don't know why it would break like that.

I clean my chain every two weeks and clean the cassette thoroughly as well every two weeks. Or after a wet ride I will also clean it thoroughly. So it has been well looked after.

I sprint a few times every ride so I don't know if that could contribute to it breaking so quickly. I got 5 000km from my previous chain and it never broke. And I also sprinted that much on that chain. So I don't know.

Any ideas what went wrong? Anything I am doing wrong?

cougie

Two weeks can be a long time in chain life. I know i broke a chain when the Pin worked loose. I heard the chain making a noise but i forgot to investigate. Did it snap or did a Pin come out?

AK_jnr

Bad luck, poorly indexed gears, cross chaining etc etc. Chalk it up to being ones of those things that happen to everyone and get back out there and nail a sprint.

964cup

Happens. Can be a dodgy shift, or just bad luck. The trouble with modern 11-speed chains in particular is that they're just not very strong - thin side plates, hollow pins etc.

cycleclinic

A twisted link or other damage will be the cause. Also 5000km from a chain it should be so worn that the cassette should also be worn. Every time i have run my chain for nearly that long i have had to change it because the shifting has got really iffy.

Bobbinogs

Have a close look at the broken chain and see if you can work it out. A lot of chain breaks are caused by the rider's poor shifting technique (excessive cross chaining or shifting under extreme load) or bad maintenance (re-using pins/links that shouldn't be re-used, poor use of a chain tool, etc.). The odd chain will just break but that is a rarity.

Mad_Malx

Did it break at the join?

MozBiker

Cougy.

The chain link is bent open and the pin is also bent.

Ak_Junior. My indexing is very good and I am conscious of not cross chaining. But perhaps I have done this unknowingly.

964cup. Might've been a dodgy shift. I accelerated, shifted, kept building speed then it went. It is a 10 speed chain just by the way.

MadMalx. Yes it broke at the join.

The Rookie

Bending is normal, the sideplate one side pops off the pin, the load is then offset from the remaining working sideplate and bends the pin and sideplate, them not being bent would be unusual!

crankycrank

Well if the link came undone then it's most likely poor installation if it happens to be the masterlink or it could also be a defect. Did you do the install or a shop, what make/model chain, any photos? Pushing in the link pins can be a little tricky and has to be done very precisely. Many chain failures are due to poor installation. If the chain is salvageable just replace the bad link with a re-usable version which have proven to be very reliable and easier to install.

paul_onabike

It can break in this way if the chain is put on with the direction of travel reversed. Was it fitted the correct way round? The fitting instructions usually supplied highlight this.

smoggysteve

I snapped a chain once after less than 50 miles. 3rd ride on it. Used a missing link so not me putting in a dodgy pin. Sh1t happens some times

964cup

MozBiker wrote:

964cup. Might've been a dodgy shift. I accelerated, shifted, kept building speed then it went. It is a 10 speed chain just by the way.

Dura Ace 7900? I snapped one of those going up Swains a few months ago. Got out of the saddle to chase someone, shifted to a harder gear and snap. I think having the pierced sideplates on one side only makes them particularly prone to bending if you shift at the wrong time (bike is Di2, so I didn't fluff the shift, but probably went too hard before the chain had settled).

MozBiker

crankycrank wrote:

Well if the link came undone then it's most likely poor installation if it happens to be the masterlink or it could also be a defect. Did you do the install or a shop, what make/model chain, any photos? Pushing in the link pins can be a little tricky and has to be done very precisely. Many chain failures are due to poor installation. If the chain is salvageable just replace the bad link with a re-usable version which have proven to be very reliable and easier to install.

I did the install myself. I don't have any photos. But I believe my indexing was slightly off and I shifted under load. Thus a delayed shift and when it shifted it came off.

MozBiker

Paul Onabike wrote:

It can break in this way if the chain is put on with the direction of travel reversed. Was it fitted the correct way round? The fitting instructions usually supplied highlight this.

Yes it was fitted the right way around. I checked this twice and read the owner manual before even taking off my old chain.

MozBiker

964Cup wrote:

MozBiker wrote:

964cup. Might've been a dodgy shift. I accelerated, shifted, kept building speed then it went. It is a 10 speed chain just by the way.

Dura Ace 7900? I snapped one of those going up Swains a few months ago. Got out of the saddle to chase someone, shifted to a harder gear and snap. I think having the pierced sideplates on one side only makes them particularly prone to bending if you shift at the wrong time (bike is Di2, so I didn't fluff the shift, but probably went too hard before the chain had settled).

No it is not a Dura Ace chain. My old one was dura ace but didn't give me any problems.