Course: There were two relatively flat stretches, both along rivers. Otherwise you were going uphill or you were going down. You really can't see any flat areas on the elevation graph.
Equipment: I rode Kelly's winter bike. This is a medium sized frame fat bike. We initially built it as a fat bike then converted to a fat bike with road bars. This past summer I converted it back to a fat bike with a SRAM XX1 mountain bike group that I had left over from converting my Lamete fat bike to eTap. For both fat bikes we have a summer wheel set for ripping around the farm. One of these has HED raptor hoops and their best hubs. The other set has Thune hubs, and Lamere hoops (cheap Chinese). They both have Schwalbe G-one 2.75" all-round tires. Kelly's bike has a 32 tooth front chain ring with a Quarq power meter (nice). My fat bike has a 28 tooth raceface crank set. Both have 10-50 SRAM XX1 Gold cassettes in the back. The XX1 manual shifter is increadibly smooth and is almost as effortless as the eTap. It is far better than the Shimano GRX that is on my Trek Checkpoiint SLR7. That is the electronic version but it is slow and hesitates when shifting down to the lower gears. In fact you can spin half a revolution going between the 9th and 10th gears. And the rear cassette is heavy! I compared the weights of the two wheel sets. The front and rear wheels of the Lamere wheel sets (with cassettes) were: 4.81 lbs (2180gms) and 5.71 (2590gms). The HED raptors were: 4.05 lbs (1835 gms) and 5.03 lbs (2280 gms). That is a total difference of 1.44 lbs or 655 grams. With the HED wheels and XX1 rear cassette my bike weighs the same as the Checkpoint with its gravel tires (about 21.5lbs).
The 907 (Kelly's bike) was great for this course. I don't know if I needed those wide tires but I could go anywhere on the gravel without any problems. Lots of other riders had to find the track with the least loose gravel, and there was a lot of contd in other record of this ride...