quick Q (that I ought to know the answer to)
 

I know cogs and chains come in 1/8" and 3/32" and that 1/8" are meant for the track. Or were, originally.

My question is this: Do chainrings also come in those 2 sizes/thicknesses? If so, are my Sugino 75s that came stock on a KHS flite 100 1/8"? I would think so since they are 165 mm, right? But there appears to be a more lateral range of motion of the chain on the chainring than on the (1/8" EAI) cog.

thanks.

chainrings do come in two thicknesses just like the cogs and chains. both 3/32 and 1/8 are for track. i don't know what chainring comes on the stock sugino cranks, but it could be 3/32 and therefore have more lateral play if the chain and cog are 1/8, but i don't know why khs have built up their bikes with different chainring and cog thicknesses...

it could also be that the chainring is a really cheap one that isn't quite 1/8". i've had the experience that some cheap cogs claim to be 1/8 but are a touch thinner.

The 75's that came on my KHS were 3/32".

yeah, that's it.. the chainring is 3/32.
and, not that it matters, but KHS didnt send it with a stock 1/8 cog. the cog was an after-market purchase, to help my then-newbie legs get used to riding fixed in SF.
I think the cog it came with was 3/32, too, matching the chainring.

thanks!~

You could also (theoretically) run BMX cranks, which are a snap to space for perfect chainline. Profile makes 110mm bolt circle rings for BMX racing up to like 48t and Crupi goes up to 51t, I think. 1/8, since that's also the standard for BMX. :D

Most BMX stuff actually seems to be 3/32 these days.

I'm a bit confused, did you also replace the (I assume 3/32, based on the fact that the chainring and cog were both 3/32 originally) chain as well as the cog? It's been my experience that a 3/32 chain (which I assume came with the KHS Flite 100) won't fit on an 1/8 cog or chainring.

Crupi offers 3/32, but I'm pretty sure they still sell 1/8 and all the Profile stuff is still 1/8. 3/32 is pretty much only used among racers, all the standard BMX stuff for thrashing around neighborhoods and skateparks is 1/8 and 3/16.