Where can I find a 130 bcd single speed chainring with 58 or 60 teeth? I am attempting to setup a goldsprints setup using a very large front ring and a small rear freewheel.
Vuelta makes one, and you can buy it from them directly. If you prefer to buy locally and immediately, I'd suggest looking for a local shop that specializes in recumbents or trikes. Vuelta has a few distributors including KHS, so you should also be able to get many local bicycle shops to special-order you one.
I've been looking for the same thing for a while. Rotor makes a ring that might be of interest: A Q-Ring (oval shape to maximize power stroke) in a 56t in a 130bcd. That ring goes up to a 59t at the largest point. They say that it is effectively a 58T ring.
You might want to check Kraynick's Bike Shop in Pittsburgh, PA, Jerry's telephone number is (412) 621-6160. He probably has one in his multi-story shop or could know where to find one.