Hydraulic systems are proposed as an alternative to electric motors for power-assisted cycling, but they face significant efficiency challenges. The discussion highlights that hydraulic systems are bulkier and less efficient than electric systems, particularly due to the weight of hydraulic accumulators compared to batteries. While the idea of a rider-powered hydraulic system is explored, it is noted that such a system would not amplify power, violating conservation of energy principles. Additionally, variable ratio hydraulic motors and pumps are deemed expensive and inefficient compared to traditional chain drives. Overall, the consensus leans towards electric systems being more practical and efficient for power-assisted cycling.