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
Chain drivetrains are really simple, easy to maintain, mature and efficient. The efficiency is biggest point for racing, for commuting maintain and simplicity are probably the biggest points and there’s a lot of interest in belt drives that are almost as efficient (or about on par in single speed setups) and almost maintenance free.
As it turns out, it’s very difficult to come up with new better system than simple chain drivetrain.