A huge +1 on the karate monkey. I've had mine for a month and a half and buying it was a great decision. Mine is geared but it could still be a badass single speed. I ride it on everything from congested urban streets and hilly mountain roads to single track and fire roads. I havent quite found the perfect tire to do all of it but I've yet to try out cyclocross tires. I built it with On One midge drops with road levers and I really love this setup. The only thing that sucks about the bike is taking the rear wheel off. The Karate Monkey has rear facing dropouts and I am running disc brakes so I have to loosen the brake to pull the wheel out. You can run cantis or V's though and you won't have this problem. Hope this is helpfull.