Swenor Fibreglass Standard #2 Rear Wheel Complete. The larger diameter classic wheels roll over rough pavement and loose gravel more easily than the smaller wheels. Breadth is added to larger wheels to add stability in compensation for a higher center of gravity. Larger diameter wheels will sustain more use than smaller wheels of the same hardness. Smaller diameter wheels keep skiers closer to the ground for stability and are lighter. Just as warm snow is faster than cold snow Swenor rollerski wheels are faster at warmer temperatures. All training skis come with the #2 medium speed standard. #1, #3, and #4 wheels are available as accessories. #1 is a fast racing wheel. #2 replicates snow speeds when temperatures are colder than 77F(25C) and #3 replicates snow speeds when temps are above 77F. Advanced classical skiers tend to enjoy the slower speed (more work) of the softer #3 classical wheels, which also tend to wear more quickly.