drive train build-up
 

I'm converting. It seems from what I've read that 1/8 is the preffered chain size. I prob should get a new chain anyways (as my old one, has years and years under its belt). I see that some people will leave their road chainring on (3/32?)and use it with the track/MB chain and cog size, and that this works. It makes more sense to me though to stick to one size.
I'm gonna have to cop a cog asap. Should I just stick with road size (3/32 or somethinglike that?). If I go to 1/8th, I don't want to have to spend like 75 dollars for a chainring. Can I go to a bike shop and get a run of the mill BMX chainring (as I've heard that run of the mill BMX chains are good)?...will that be a lot cheaper?

Also, on my old Peugeot road frame that I'm using, I have 1 inch of space in my dropouts. Should I not have any problem fitting most gear combinations with this amount of spacing. I'd like to figure out a combination without having to do much trial and error (aka..buying **** I can't use).

thanksk

I am one of those who run a skinny road ring with a 1/8 chain. No problem, smooth and silent. I think it's even beneficial if your chainline is not spot on, as the chain can find a more straight route to the cog. I wouldn't use a 3/32 cog with a 1/8 chain, though.
If you don't want to mix, just go 3/32, but I'd mix.

I was originally going to go 3/32" on my first conversion, but my LBS didn't have any 3/32" cogs or chainrings in that size, and I didn't want to wait, so I bought all new 1/8" parts. I simply assumed that I would want the chainring/cog/chain to be all of the same width. It never occured to me to mix and match.

What's the reasoning behind saying that it's okay to have a skinny chainring as compared to your chain, but not so of the cog?

The cog has a far lower tooth count, so the chain can move around on it more. The same 1mm play can create a wider angle, possibly getting rattly or even throwing the chain off if it's loose. I'm not absolutely sure it'd be problematic, but I gather this is the consensus.
About the chainring, pretty much everyone agrees there's no drawback to mixing except aesthetics or really anal perfectionism.