I installed these on my Razor A5 Lux to smooth out the ride on rough sidewalks and streets. The front wheel went on with no modifications. The back wheel required the addition of a small spacer washer on the out side on the bearing washer that Razor provided; one required for each side. I also sqirted in a small amount of Slime innertube sealant into each tire before inflating to 100 PSI. The wheels work great! With the Slime, they hold their pressure for at least 2 weeks. I have put over 100 miles on the wheels in 2 months. Dave, in the technical sales department, helped me order the right part. I will order these again!
I put these on my Razor A5 Lux. They really smoothed out the ride, but I do have to kick more. I also had to add some 1 mm washers since the original Razor wheels are about 2 mm wider.