Singlespeed/direct deive chain load (strain) estimate, anyone?

FurryOnTheInside

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I'm just wondering if anyone has any idea how much load is the chain carrying on a standard 10/44 kit setup.
I have been looking for comparisons between the different standard chain sizes and finding only comparisons of the same size but different brands (those seem to differ far more by wear rate than BS), however the one chart I found showing different sizes of the same brand showed that their (DID) chains have the same average breaking strain (BS) no matter what size (1/8" or 3/16") except their "track racing" 1/8" which I am assuming has thicker side plates, possibly better material.
I am just trying to figure out what the lightest, narrowest chain is that would work (if the sprockets were narrow enough to match).

So yeah, in short what is the minimum BS necessary for direct drive motor chain?
 
regular old bmx chain holds up just fine, but the chain line has to be 100% perfect, don't want any loading in the wrong direction.
 
regular old bmx chain holds up just fine, but the chain line has to be 100% perfect, don't want any loading in the wrong direction.
Uh huh of course it wants to be straight. I'm sure quality 1/8" BMX chain is okay since 1/8" has the same BS as 3/16" , ATBE. Same side plates means same BS. (9000N+)
I'm just wondering what the actual strain is or what the _minimum_ acceptable BS would be.
Tbh the 9 speed 3/32" chains of decent brands are about the same BS.. 10 speed are lower BS but that's to be expected.
 
this only covers the common chain sizes but it'll do

Size_chart_grande.JPG


if I wanted to go with the minimum possible size I'd go with a #38, which has a tensile strength somewhere on the order of 3000 pounds and has an inner width of 3/16

you could probably get away with a #37, which uses the same side plates as #38, but with smaller rollers (1/8th inner width) so I'd be concerned about the sprocket flexing or getting bent and the teeth wearing down too quickly.

they both have the same half inch pitch as the #410 that the kits come with
 
this only covers the common chain sizes but it'll do

Size_chart_grande.JPG


if I wanted to go with the minimum possible size I'd go with a #38, which has a tensile strength somewhere on the order of 3000 pounds and has an inner width of 3/16

you could probably get away with a #37, which uses the same side plates as #38, but with smaller rollers (1/8th inner width) so I'd be concerned about the sprocket flexing or getting bent and the teeth wearing down too quickly.

they both have the same half inch pitch as the #410 that the kits come with
I think you attached the wrong picture, which confused the tihs out of me for a moment, haha.
I take your point about the increased wear rate of a narrower chain and sprockets. The sprockets can be thicker than the teeth at the edge though so I doubt bending would be a problem. I just got a possibly silly idea in my head about a "dingle" sprocket set.
Thanks for your input. :)
 
just saying, or hunt up apps which place similar stresses on chains, and copy what they specify. Cargo bikes, concrete mixers...
 
just saying, or hunt up apps which place similar stresses on chains, and copy what they specify. Cargo bikes, concrete mixers...
The dingle system is from fixie cycling but I am sort of convinced it's all moot because chain width affects wear rate (not worth it unless theres a decent advantage) and as there's little room for different sizes of front sprocket even with modification (little range difference, so little advantage), would take extensive modification at the very least, which I don't have the capability and tools to do.
I still think a dingle is worth looking at for other single speed engines. Just not for me and the little Chinese generic bicycle engine with its enclosed drive sprocket.
 
I'd guess a 2000lb chain is OK for these - the 415 chain that comes with most kits works well when installed correctly - saving a 1/4lb there doesn't seem worth the effort (skipping breakfast would probably do more).
 
I'd guess a 2000lb chain is OK for these - the 415 chain that comes with most kits works well when installed correctly - saving a 1/4lb there doesn't seem worth the effort (skipping breakfast would probably do more).

I wasn't actually thinking about weight at all but outside width, and the possibility or not of a dingle system. Dingle is two sprockets front and rear, sharing (taking turns using) the same chain. Manually changed between the high and low ratio gearing (but without need of tools). I have become convinced it is only worth lookin into for other engines but not the Chinese generics because of the dimensional constraints and concentration of wear on narrow chains. Goggle the "Surly dingle sprocket" if my explanation sucks.
 
not sure how those are different from freewheel or cassette with only two sprockets on them
 
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