There were some cold forged cranks sold under the 'Mighty' model designation that were a step above the Impel. Spec'd on some US Kona models like the Explosif back in the early 90s. They were 5 bolt compact ring compatable cranks with one of the bolts hiden behind the arm, if memory serves. Quality was very nice, Sugino's answer to XTR. If you have that model Mighty, you should snap a pic and post in on the board so I can drool over it, then you should ride the sucker on your singlespeed without regrets.