Trek Farley 9.6. Sunny and almost cloudless sky, warm - mid 70's, moderate SW winds, 8-10 mph. Official route was around a 60/40 split gravel & trails/pavement. I rode out to Afton Forest Preserve, riding mostly grass trails which were very slow with the new knobbies and the grass was a bit high. Plenty more trails to hit next time. I started the ride with a one mile loop through the woods at Lone Grove, then I pushed pretty hard into the wind out to Crago Rd, arriving at Afton with an 11.2 mph avg speed. My average dropped to 10 mph with all the slow grass but I picked it up on the return leg and pushed the avg back up to 11.1 mph. No other cyclists and no critters spotted but quite a few walkers and hikers out enjoying a beautiful Spring day. The fat bike is great on gravel and grass. New 45 NRTH Dillinger 5 - 4.5" tires roll great and have wonderful traction.