Single Speed

Video from Single Speed World Championships in Portland, it is in Seattle this year.

If you are a beginner, Single Speed is not a bad option. I would recommend it actually. You get a much lighter, stronger bike for less money. You just gotta get a good gear and you are off. Not having gears to shift gives you a more level head during the race so you can focus on other riders and navigating your bike.

Single speed bikes also have great mud clearance and less of a chance to have a mechanical. It is also safe to say that replacement costs are much less. Say you crash your drive side on geared bike, you are out a derailleur, hanger, maybe bent chain...$100 at least, but not with a single speed.

You can buy a descent new ss cx bike for about $500, a great one for $800, or a used one cheaper than both.