Singlespeed Cyclocross Gearing
So, I've finally decided to take the plunge into the exotic world of singlespeed cyclocross. All of my other bikes are either singlespeed or fixed gear, so this just seems like the next logical step.
I'm planning to set up my rear wheel with a Surly bmx cog and a stack of aluminum cassette spacers. I have a Rennen Rollenlager chain tensioner on my ss mountain bike conversion that I'm going to borrow to take up the chain slack. I'm already running a single ring up front with an outer chain guide and a Third Eye Chain Watcher, so no modification is required there.
My question concerns gearing. I'd like to use either a 38x18 or 42x18 gearing, mainly because these are the sizes I have on hand. So I'm wondering what kind of gearing other singlespeed cx'ers are using, or if there is some magical do-it-all gear ratio for cyclocross. For what it's worth, It seems like the cyclocross courses here are getting faster and less technical, so I'm leaning towards the 42x18 gearing.