Ed,
Most seem to do the event on cyclo cross bikes,, they have nobby tires, fairly low gears, are pretty rugged and almost everyone has one hanging in the garage. On a forum a few years back they were dubbed the "ideal" bike for D2R2 by some.... not a bad choice but there are other
options.
The climbing doesn't end at D2R2 so low gears,, (the lower the better) as the constant climbing really takes it out of you. My first event I went with a 48-36 with a 13-30 rear and I thought I was good,, but I wasn't, and walked a few times,(hate to admit it,, but I did)...and felt hammered at the end.
Last year I put a triple up front and I used the granny a lot, but I had enough gears and had a great ride.
I've ridden Hetre's and Pari Moto's and both were great. Tire pressure has to be adjusted so the tires feel fast on the pavement, and supple enough on the gravel, especially on the FAST gravel descents...
After the photo was taken I switched to PM's, and with this particular bike I felt a bit more "dialed in" so I rode them. I did have a rear puncture last year, a sharp thorn, nail, who knows? Could
have happened regardless of what tire I was using.
The cross guys so seem to pinch flat a lot. Like any tire if they're too hard the ride is rough and dangerous in the bad sections. The tendency is to drop the pressure for the ride, but then you get pinch flats.
With a full 38-42mm 650b, you can drop the pressure, but the volume helps prevent the pf's...
I always have wondered how many of the cross ya-hoo's would even start the event if it was raining that day? In a real cross race you ride roughly an hour and you're done, no worries if you get a little muddy.
At Deerfield you may be out for 4-7 or so hours. How much grit do you want to eat that day? Just trying to drink out of a bottle that is
covered in grit becomes difficult.
IMO, fenders are great regardless of the weather. Up there in the hills you never know when conditions will change. Fenders protect you, and you bikes drivetrain, brakes etc,,, they do no harm as long as theyre installed and ajusted properly. D2R2 is the ultimate fender durability test.
And as long as we're talking about water,,,make sure your cages are really good and hold the bottles well. It is a common sight to see many, many bottles lining the sides of the fast and rough descents. My flimsy looking Nitto's have never let me down, never rattle, and always look stylish;~)
My hints would be,,,
Wider tires are better imo. Pressure is everything, tread not so important,,, there is quite a bit of pavement as well as the gravel.
Low gears,,, lower than you think you need,,, good to have a bail out gear or 3.
Practice climbing on very steep gravel sections to condition yourself, and to test gearing and derailleur function.
Bags and bottles need to be secure if you plan to descend at speed,,,
There is plenty of food at the check points, but I always have my own stash of energy food that agrees with me.
D2R2 is a very cool event. You'll see many different types of bikes from 23mm road bikes,(yikes,, ouch) to cross, to 650b rando, and some mountain bike thrown in as well. Ride
what ever you are comfortable with. Some ride it fast, and many just ride along at a leisurely pace. There are several distances to choose from. I like the 100k, as one of my friends says,, the 100k feels like 100 miles by the time you're finished.
Just be sure and gear low, test ride the bike in similar conditions if at all possible, and start
training.
Hope this helps, and hope to see you there!
ptr