> The Stringbike is a bicycle that uses a rope and pulley drive system instead of a traditional bicycle chain and sprockets.[1][2][3][4] It uses two Dyneema ropes attached to pulleys attached to swinging lever and cam mechanisms, one on each side of the bike. These mechanisms replace the round sprockets found on chain-driven bikes. Unlike some traditional 10-speed gears using a derailleur, there is no slippage when changing gear ratios.[5] The Stringbike uses a 19 gear ratio system with no duplicates and a total gear range of 3.5 to 1. The transmission ratio can be changed with a shifting knob located on the right-side handle grip. Gear ratios can be changed even when the bicycle is almost stationary.[6]
> Hungarian designers from the manufacturing company Schwinn Csepel Zrt, unveiled the bicycle in 2010 in Padova, Italy.[7]
It never caught on so possibly isn't better than a chain design, but maybe it simply lacks popularity or the idea might be made use of for some other application