First time ordering these carbides from Bergstom, He's an extremely informational guy. I'm coming from a pair of dooly's to bergstrom (good But Ulgy) single carbide 6", 3/8'" ski saver inhancment along with shim under heel of ski boot, I'm kinda dissappointed, it seems everything that they said would fix or make easier hasn't appeared sofar, "Don't need power steering to turn" actually harder to turn the ski's now than before, "Eliminates Darting issuse" sled seems as if it finds ruts in the trail by itself, I've tried the preload in increments from the high to low spectrum, the darting was less as the preload pressure was decreased but I'm starting to think the preload is to little. Trails were good (flat) but beat up with lack of grooming for awhile (needed more snow), was an icy base and ruts were numerous. Friends we were with didn't have hardly any darting issues (same sleds). Did I make a mistake when changing from dual carbides to these single's. If I did I have 2 pairs for a polaris plastic ski Bergstrom Carbides for sale!