A trials unicycle is a unicycle designed for unicycle trials. Trials unicycles are stronger than standard unicycles in order to withstand the stresses caused by jumping, dropping, and supporting the weight of the unicycle and rider on components such as the pedals and crank. The wheel on a trials unicycle is usually 20" to give maximum agility, but some riders prefer larger wheels. The tire is generally wide and thick, giving a large air volume. This is to cushion drops and allow large hops and jumps. Strong spokes and rim are used to prevent the wheel deforming under these conditions. Some trials unicycles have a splined hub and cranks, as this design tends to be more resistant to bending and breaking than the more common cotterless equivelent. Long cranks give the rider extra torque and large grippy pedals are used to prevent the riders feet from slipping.