I hop on 13's and I believe its harder to achieve higher inches when hopping on 14's or stocks. I think its from the tire size and amount of air in them. I don't know I could be wrong and there's more to it. I noticed that hoppers in LRM shows use 14's with bigger tires, I've never really take notice them using 13's. But I use Black Magics's comp cylinders and not those huge ones cause I was told they're more for double pumps.