Hi Joona! The 15.00" diameter models are currently only available in 26 to 27.5 pitch. The XP version features the same Pro Finish recipe as the 14.63" Rev 4 XPs, meaning leading edge geometry and cups are all in line. The blades do get slightly thicker through the center radius and out near the trailing edge, to help support more demanding surfacing applications. We have found that in most cases the added diameter provides more mid range lift and actually makes up for the increased thickness in terms of acceleration. Pitch progression is the same as the other Rev 4s, so expect a 300 RPM decrease when going from a 25 to a 27 pitch. Rev 4s are cast in odd increments, and we remove some cupping to make the evens. I've found these days a lot of the four strokes prefers the evens/ less cupping. In some cases it allows you to step up in pitch, which leads to big gains in mid range economy and top end speed.
