I went with the 12T sprocket on the front for a couple of races. It does seem to give you more low end, but at the sacrifice of top end. It worked great in the tight woods and big hill climbs. But when you hit the open stuff, everybody blew right by me. I went back to the stock 13 and 47, learned to keep the rpms up a little more and this seems to work good for me. For the enduros with extremely tight stuff and very few roads, I'm getting a 49T to go on the rear. That should be perfect.