chaain snapped

[PatrickPending]

first day back commuting by bike (10 days of snow and ice meant the car was used) chain snapped on the way home 10km into my journey. Fortunately i carry a sram missing link so after getting covered in oil i was able to complete the further 26km to home. bit of a first for me not had a chain snap in 20 years oh well.....

 

[HJ]

Hard luck

 

[Brains]

You must be lucky.

I recon I snap a chain at least once every coupe of years, after punch****s I'd guess it's my next most frequent 'show stopper' issue

 

[mgarl10024]

I recon I snap a chain at least once every coupe of years, after punch****s I'd guess it's my next most frequent 'show stopper' issue

Really?
Is chain snapping that frequent?
How do you guard against it? - carry a chain tool and simply remove the snapped links, reattach and carry on?

 

[GrasB]

Frequent chain snapping is typically a sign of not looking after or replacing a chain when it's worn out. I've snapped 2 chains in my cycling career, one was being stupid (chainring up a chainring under full out of the saddle load), the other time was when I was while riding on an old chain I've normally chucked but I didn't for various reasons.

 

[661-Pete]

One cause I believe is incorrect positioning of the rivet after using a chain tool, especially on a 9-10 speed where tolerances are very tight. Is it true that you should never connect such a chain using a rivet tool, only use it to take links off?

Anyway, it seems PP did the right thing by carrying a powerlink. So it wasn't so much bad luck, nor even good luck, just good preparedness. And therefore: completed journey. We can all learn a lesson...

 

[BlackPanther]

If you clean and lube the chain regularly, don't stand up on the pedals, buy a decent quality chain, and replace them before they reach their stretch limit they shouldn't snap. That said, a mini chain tool and a spare link don't take up much room and I always carry them.

I've always avoided standing on the pedals, and I've passed quite a few uphill pedal standers.

 

[GrasB]

Just because you were sitting down when you passed the guys standing up doesn't mean you were putting the chain under less stress by being in the saddle, the more watts you're producing the more strain you're putting on the chain. The fact you passed them meant you were putting more strain on the chain than they were, assuming they were the same build, as you were producing more power to propel you up the hill faster. The reason people break chains when standing on the pedals is because typically they're making their highest power then, if you made the same power in the saddle & you'd still break the chain.

 

[Brains]

Really?
Is chain snapping that frequent?
How do you guard against it? - carry a chain tool and simply remove the snapped links, reattach and carry on?

I carry power links, as it's as essential as a puncture kit

When on tour and have a 'full' tool kit I can either fix or replace as the need arrises.

I use my bike for commuting, so I only get about 1-2,000 miles from a casette and about half that from a chain. 500 miles from brake blocks if you are lucky.

With some 60-70 sets of traffic lights to go through each way in a 6 miles commute the start/stop nature of the ride really hammers the drive chain, brakes and tyres.

 

[kevin_cambs_uk]

first day back commuting by bike (10 days of snow and ice meant the car was used) chain snapped on the way home 10km into my journey. Fortunately i carry a sram missing link so after getting covered in oil i was able to complete the further 26km to home. bit of a first for me not had a chain snap in 20 years oh well.....

Now thats impressive, fixing the chain out on the road,

Respect.

 

[Tynan]

snapped a chain twice, nce almost as I left home and was within a 100 yards of my LBS

I carry a link and tool these days so I'm waiting my chance

I always thought that the stand up merchants were putting far more stress on a chain by effectively stamping through the pedals while a someone sittings was putting power through the cracnks more smoothly?

 

[GrasB]

When I got my Q-rings dialled in I was riding on ergo trainer that could give power traces for each foot & thus the entire pedal stroke. Apparently my power wave forms were fairly typical. In the saddle I produce a fairly good approximation of a sine wave with the exact offset being dependent on rpm.

At 70rpm & bellow it's actually slightly kinder on the chain for me to stand up! For a given wattage I'm producing less peek power but I use more of the stroke to produce the same power over a revolution of the crank. So the power wave form looks like a heavily rounded square wave. However out of the saddle I can produce a lot more power than in the saddle so my capacity to put strain on the chain is increased.

Now if I look at my sprinting cadence (100rpm up) & the wave form looks a lot more like a lop sided rounded double saw tooth wave, I also pull the pedal on the upstroke. If you scale it to a sit down wattage that sort of standing on the pedals would be much harder at the same power output over a revolution. Further more I'll be producing up to around 6x the power over one revolution of the cranks. This would be known as chain stress torture.