This trail description is South-to-North. You will want a shuttle vehicle at the other trailhead off H75 Road. We used Peach Valley Road to drop the shuttle at that end.
The Sidewinder Trail is a relentless, rocky, technical, physical adventure on the bike. There are very few extended climbs or downhills, but my GPS still measured 2500' of climbing and 3000' of total descending by the time we were done.
Mostly it is a constant mind-game of rocky, technical bike-handling tests. There are very few sections of fast cruising. The trail is extremely well-built though so the technical challenges are mostly rideable for a skilled rider. There were 6 of us on our ride and while we were all bucked-off at various places, usually a couple of us would clean most features.
As the name implies, the Sidewinder weaves in and out of many arroyos as you cling to the western edge of the Gunnison Gorge Wilderness Area. You will climb and descend these arroyos enjoying many slickrock drops and ledges along the way, as well as about a thousand other rocky treats.
The Sidewinder is not for beginners. I would imagine they would hate it and probably wind up hurt. For a rider loving a technical, physical workout its one of the best trails I've ever ridden. It took our group 5 hours to ride the whole thing including all our breaks and lunch and all that. If you google "Sidewinder Trail" then you will find a map on the BLM website that shows the route and many other bailout options.
Go ride it... you will not be disappointed.