Inch Pitch Experiment

General Fixed Street
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Was bored tonight so thought I’d perform a little experiment. This may seem straightforward to some but hopefully a few of you find it interesting. I’ve got some inch pitch gear lying around waiting to go on a build, and there is often talk about the difference between the standard 1/2" pitch stuff that most of us ride and the older 1" pitch. For the newbs pitch refers to the space between the teeth (As measured on the circle).

Here goes…

1" pitch chainring:

1" pitch chain:

Together they are good friends:

1/2" pitch chainring (standard) with 1" pitch chain. On this the teeth that sat between the rollers found there way between the rollers a little, but of course it just didn’t mesh:

1" pitch chainring with 1/2" pitch chain. So this is the one that may surprise a few. These two didn’t mesh properly. The reason is simple, to accommodate the extra space between the rollers on the 1" pitch chain, the 1" pitch chainring has chunkier teeth, and the rollers on the 1/2" chain are spread apart more than on the 1" pitch chain. This means that the gap between the rollers on the 1/2" chain isn’t big enough for the teeth on the chainring to fit through:

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YES I WAS RIGHT :smiley:

(referring to separate thread… will find quote)

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“FUCK WITS” “fuck” “f@#ers." "f&%k my s#!t up” “cock sucking” “fag licking” “dick” “…fuck tard…shit…fucking bike…” “dicks” “fucking technical” “bullshit” “fuck sake” “cunts” “pussies” “wankers” …tourettes? :oops:

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That would still fit with a standard 1/8 chain. [/quote]

lol bender :stuck_out_tongue:

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Yeah sorry Marty. Logically I had always thought it would work that way but have had a nagging feeling for a while that it wouldn’t.

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YMMV but all the 1" pitch stuff I have is 3/16" which is thicker than 1/8". Not sure why but I think with less teeth it made more sense to opt for thickness (less flexible chain) and indeed the chain I use is a block chain which has no rollers but a solid piece between the plates. Below shows the difference between a block chain (a) and a normal roller style chain (b) …

A 1/8" chain won’t fit on an 3/16" chainring just as a 3/32" chain won’t fit on a 1/8" chainring. There is some “skip tooth” 1/8" stuff in the US on Schwinn roadster bikes with internal hub brakes but from what I have heard is not sturdy or proper 3/16" old school track. Inch pitch cogs and chainrings are plentiful and cheap because they are thick and mofo tough so plenty survived … but inch pitch block chains are quite rare now, worth a packet and what everybody is always looking for.


As you can see above I could use a spare link or two:-D I’m running 24/8 (equivalent to 48/16).