I would take a pump, two tubes, a patch kit, multitool, spare chain link and tire boot. And then clothes, food, and water would depend on weather and where you can resupply.

On the Denali Highway this year (125 mile race, there was one lodge where I could have stopped for stuff) I brought along enough food for the whole ride. There was a campground to refill water, so I had a 70oz bladder and a bottle on the frame. Because it was unseasonably warm (80+ degrees), I didn't bring extra clothes. Other years I've carried a jacket, arm warmers or rain gear. You may need to add sunscreen or bug spray depending where you are.