Over 30,000 miles on the non-stock Centa unit. H-D unit bit it after 22,000 miles. Checked and replaced rollers after about 19,000 miles. I have the originals and they still look good and solid. Honestly I fell that the life of the rollers in the Centa unit will be determined more by the driver than by the design. If the motor is lugged all the time then it will eat the rollers. Not much can stand up to those forces. Anything above 3,000 rpm is a relief to the drive train. Anything under that is a killer. The manual says to keep revs above 2,700 rpm. That is also what S&S says. Bear in mind that they are referring to motorcycles which weigh far less than the M3W loaded with people in it. Most of the X-Wedges I've seen on the road are on chopped bikes with the bare minimum on them like a double seat and a sissy bar! As an added bit of information, I had the chassis replaced due to cracking in three separate places where the motor is mounted. This was also the time when the rollers were replaced since it was all in pieces and we had access. All of the cracks were due to the starting cycle where you hit 100 ft/lbs of torque instantly from zero. This is a torque monster.