Hell, I've got urethane bushings with crush sleeves on my DJM control arms for my truck. Of course, the arms do come with zerk fittings for maintenance. However, I think all you would have to do for maintenance on a quad with urethane bushings is take the bolts out of the a-arms and splooge some grease in there periodically. I mean, if you want to ride the quad as much as you can without it falling apart due to maintenance