Greatest strain

[Brigadier]

get yourself a Topeak Mini 18 it has a chain breaker tool, keep it in your kit bag and you just take a link out and ride home.

If you want the good news, if your chain broke, its probably worn and you need a new cassette too

I have a chain tool at home, so popped a link out and stuck it back on.
I suppose I'll have to do some boring loops close by, to check it .

To be honest , I have become a regular mtb'er (prefer openwater swimming to the pool, hence swimming has been less regular than it would be usually), but I would call myself "reluctant", as opposed to "keen".
That said, I am coveting a new bike, front susser, 1 x 12, something light and simple, and less than a k.

 

[dontbelieveawordofit]

Depends on how the chain is fitted and tensioned.
Usually the pedal sprocket is the driving force so the teeth will be 'pulling' the chain and hence be under the greatest strain. The smaller, wheel sprocket, will be under tension when first starting but once rolling it's own momentum will help to reduce that strain. It's virtually impossible to tension a chain to such accuracy that it is even all the way round. You tend to get a bit of slack on the lower section as it comes off the driving sprocket. As this means it is being pushed as it comes off the driving sprocket it follows that this releases some of the pulling tension by the wheel sprocket. Ergo, the pedal sprocket is the one under greatest strain in most scenarios.

your’e either an engineering genius who just bamboozled us all with science or what you said is complete nonsense and you never owned a bike.
I can’t decide.

 

[Mottie]

Well, you lot have done for me.....

Going up a tidy hill over The Chase tonight , I snapped my sodding chain

Six miles of scooting the downhill bits, and pushing the rest, to get home

Since my chain snapped going uphill in too high a gear, I now carry a spare chain in my seat bag. It is a KMC chain and comes with the missing link so no tools needed to fit the new one should it happen again. Mind you, that was a good few months ago and I’ve only been out on it once since! I also carry a spare inner tube as well as a puncture kit, a mini pump and some tools. I’m surprised you, being a keen cyclist, don’t carry at least the same. (Or am I mixing you up with someone else on here?)

 

[conny]

your’e either an engineering genius who just bamboozled us all with science or what you said is complete nonsense and you never owned a bike.
I can’t decide.

I'm used to be a regular bike rider and am engineer by trade. Fitted many motors and gear box drives using sprockets and chains of many sizes and types so no, what I have said is not nonsense. Sorry if you feel bamboozled but my facts are simple to check and, if you have done any engineering, relatively easy to understand.

 

[EFLImpudence]

Just think of a tug-o-war rope.

Would anyone think the tension in the rope can vary through its length?

 

[dontbelieveawordofit]

I'm used to be a regular bike rider and am engineer by trade. Fitted many motors and gear box drives using sprockets and chains of many sizes and types so no, what I have said is not nonsense. Sorry if you feel bamboozled but my facts are simple to check and, if you have done any engineering, relatively easy to understand.

it’s just you answered with such knowledge and authority, but i reached a conclusion. I think it’s wholly inaccurate and fundamentally wrong. but hey, no offence intended.

 

[Munroast]

I have a chain tool at home, so popped a link out and stuck it back on.
I suppose I'll have to do some boring loops close by, to check it .

To be honest , I have become a regular mtb'er (prefer openwater swimming to the pool, hence swimming has been less regular than it would be usually), but I would call myself "reluctant", as opposed to "keen".
That said, I am coveting a new bike, front susser, 1 x 12, something light and simple, and less than a k.

So what failed on the chain ? side plate pulled off? and did it fail where you joined it?

 

[Brigadier]

Just at some random point; the quick link thing was still fine.

I popped the chain into my pocket , and rejoined it (albeit a link shorter) when I got home.

I'll have to get a spare, and trial the repaired one later in the week.

 

[Munroast]

Just at some random point; the quick link thing was still fine.

I popped the chain into my pocket , and rejoined it (albeit a link shorter) when I got home.

I'll have to get a spare, and trial the repaired one later in the week.

as long as there is enough length for it to work from big to big - just in case you make the mistake of seleting that combination.

 

[Brigadier]

as long as there is enough length for it to work from big to big - just in case you make the mistake of seleting that combination.

I'm considering going 1 x 11 or 12, if I can find one in stock, and lever open the kung fu death grip on my bunce

 

[Harry Bloomfield]

Mmm. Well the torque is greater at the front, cos the pedals extend the radius of the front sprocket. But not sure how that theory helps! The 'strain', should only be applicable at the top of the chain, since the return part of the chain is slack enough to need tensioning. So I'm proposing that the 'breaking strain' is equal on both. But hey!

Equal strain on the chain from where it leaves the large cog, to where it meets the smaller cog [1]. There is much more torque on the small cog itself, than the large cog, but the amount of difference, depends on the ratio of the two cogs.

[1] Strain on the chain increases, from where the chain enters the large sprocket, to the point it exits. On the smaller driven sprocket, strain will gradually diminish between entry of the chain, to where it exits.

 

[Munroast]

I'm considering going 1 x 11 or 12, if I can find one in stock, and lever open the kung fu death grip on my bunce

didn't know they were up to a 12 speed cassette - even thinner chains with more sideways articulation, can imagine even more chains failing.

 

[Harry Bloomfield]

Just think of a tug-o-war rope.

Would anyone think the tension in the rope can vary through its length?

It can! In a tug of war, there will be a number of people (teeth on the sprocket) on each end of the rope. Strain on the rope is greatest at the front at each side, where all members of the team are pulling, least strain at the very rear team member.

 

[Munroast]

It can! In a tug of war, there will be a number of people (teeth on the sprocket) on each end of the rope. Strain on the rope is greatest where at the front at each side, where all members of the team are pulling, least strain at the very rear team member.

it seems easier to think about a long rope suspended between two points, the weight of the rope itself will create tension and that will be greatest near the fixed point at each side where the weight will be greatest. Once pulled tight that weight will still have its effect but becomes proportionally less the greater strain put on the rope. A bike chain is light and forces are great so I would imagine negligible differences between where it leaves the sprocket to where it goes into the chain ring.

 

[motorbiking]

I have a chain tool at home, so popped a link out and stuck it back on.
I suppose I'll have to do some boring loops close by, to check it .

To be honest , I have become a regular mtb'er (prefer openwater swimming to the pool, hence swimming has been less regular than it would be usually), but I would call myself "reluctant", as opposed to "keen".
That said, I am coveting a new bike, front susser, 1 x 12, something light and simple, and less than a k.

I know the trend for 1 x is popular, but I'd like to convert my 1 x 11 to a 2 x 11 and ditch the chain device. I have a 1 x 11 full suspension and a 3 x 10 hard tail and find no real advantage of the 1 x 11. I do notice the difference in cost. (the 1 x 11 is a SRAM XX1)