This part of EN 957 specifies safety requirements for stationary exercise bicycles and upper body crank training equipment in addition to the general safety requirements of EN 957-1. This part of EN 957 is applicable to stationary training equipment type stationary exercise bicycles and upper body crank training equipment (type 5) as defined in Clause 3 within the classes S, H, I and A, B, C according to EN 957-1. Any attachment provided with the stationary exercise bicycles and upper body crank training equipment for the performance of additional exercises are subject to the requirements of EN 957-1. This part of EN 957 is not applicable to roller stands as they cannot be made safe in a reasonable way.