Chain drives (as a flexible power transmission system) guarantee largely constant transmission ratios with both small and extremely large centre distances of axes. Chain drives are better than spur gearings, especially for large centr distances of axes, since they do not require any intermediate gears and additional bearing points. What’s more, impact energies can be absorbed more easily thanks to the chain’s elasticity.
Furthermore, chain drives are generally less sensitive to dirt than other types of transmissions, though they do require a certain degree of cleaning maintenance.