Good to hear of another tandem team doing D2R2! We are signed up for it this year, it will be our first time. Stoker is getting worried about what we're in for. Are you doing the full 118miles? As for brakes, I wasn't concerned about that. We have BB7s with Avid rotors, I've never had an issue with them. I'm more curious about what tires to use. I was thinking of going for some 26x1.5 slick tires. Also planning to get a new cassette for some lower gears. We usually have a low cog of 28t (28 in the front too), thinking of putting on a 32t or 34t.