Transition TransAM 2011, size 18inch frame, designed for proper 26inch wheels.
This frame is benefits by being made of a Japanese steel which does not rust and will take upto a 6inch travel fork.
While this can be run single speed, I never did : I will send it with a seat post collar, mech hanger (and spare)
I will also include the seat post shim so it can take a 27.2mm seat post.
Has some heel rub on the seat stays and a little chain suck/chipping as you would expect in a frame that has been used.