I've been thinking about how I want to tackle the Stony Marathon XC race this weekend. The race is 40 miles, and will take 3-3.5 hours, so pacing will be key. The question is how do you ration out your energy? When to go hard, when to back off, do you even go hard at all? I feel like I might have an advantage for this race, since I think I have better endurance than most of the guys I race against. That being said, it won't help me if I use my energy at the wrong times, or don't take advantage of the "free speed" opportunities available.
The course is mapped out here. Roughly 40% of the course is singletrack, the rest is two-track. All of the more difficult climbs are on the two-track, although none of them are really that bad (easy to say sitting at my desk, I'm sure I won't be thinking that by the end of the race).
So my plan is basically this: ride at a "tempo" effort on the two-track, and back off and recover a little in the singletrack. The singletrack at Stony is, for the most part, well-suited for recovery. It flows pretty nicely, so you don't have to pedal too much if you stay off the brakes.
Update: I rode 2 laps of the course tonight. I didn't push much at all and was doing laps in the 55 minute range. This is a little slow compared to lap times from last year, but the course is slightly longer than last year, and my lap times include a couple short wrong turns and my crash. I expect to be able to pull my lap times down to about 50 minutes without too much trouble.
So, my crash... it was on a rough descent at the end of the Roller Coaster. Normally, you come off this descent, go across a "two-track" path and into the next singletrack section. No braking is necessary in that case. For the Marathon race, we have to make a hard right turn onto the two-track instead, so you need to do some pretty heavy braking to make the turn. On my first lap, I was on the brakes in the rough part and my front wheel stopped when it hit a rock. The results were predictable: I went flying over the bars. I landed pretty hard and my shoulder and hip, but it didn't do too much damage. I got some "gravel rash" on my hip and elbow and a little cut on my knee. Crashes like that are part of the reason I think it's important to exercise the entire body. Anyway, on my second lap, I braked before the rough section, rolled through it, and then braked again after... the results were much better.