jacksbike

Well, in a 10 speed bike, Shimano manufactured something like this in the 1970's to maybe early 1980's. It was called the Shimano Front Freewheeling System. The rear 5 speed freewheel was screwed onto the rear hub and did not freewheel. It move backward or forwards in the same direction as the rear wheel. Now the crankset, sometimes 1 piece and sometimes 3 piece cottered, had the freewheel built into its bottom bracket. You would push down on the pedals, and if you stopped, the 2 front sprockets continued freewheeling forward, while also pulling the rear wheel along with it. It was a great bulletproof system for beginner cyclists. Negatives-added a lot of weight to the bike, needed a special rear freewheel (that did not freewheel) special crank arms, sprockets , bottom bracket, and special (again) Shimano tool to remove the bottom bracket freehub set up. Anyway, don't know if anyone makes a single speed version of this. Perhaps a BMX knowledgabel person could answer.