I was able to go on a ride with my son today. His sled is an 800 Axys running the stock belt. I ran my 800 Axys with the Gates Carbon, air temp was 38 degrees. We were in a hurry as the wives and kids were waiting for us for a lunch date. We smoked down the trail 8 miles at roughly 75 MPH, we hit our test hill 4 times, (long WOT Pull). First run Gates sled pulled 8,200 R's, subsequent pulls 8,150. Stock belted sled first pull 8,150, subsequent pulls 8,050. We then smoked down the trail to the truck, we didn't give the sleds any time to cool, pretty much ran wide open for .5 hour. Upon loading on the trailer the sled with the Gates Carbon had squeaky clean sheaves, the sled with the stock belt had brown sheaves, both primary and secondary. I've also found that the 3211183 belted machine will occasionally fall off to 7,600 in steep and deep powder climbs, when this happens you don't have enough belt squeeze to keep the belt from slipping, everything goes in the toilet from there. I love the Gates Carbon but I can't seem to get the life out the them the stock belt delivers, 300 to 400 miles compared to 600 to 700 for the 3211183.