Ideal for climbers although not just for them racing light xlr wheels low profile extremely lightweight full carbon rim very stiff and reactive fulcrum 21 spoke ratio on rear wheel double the number of spokes on the drive side for greater wheel stability and improved power transfer in the rear wheel 22 radial aero spokes on front wheel 24 on rear carbon hub body and oversized flange on the drive side fulcrums cult ceramic ultimate level technology bearings 9 times smoothe