A quick update. The 110 km (70 miles) and 3,200 m (10,500 ft) of ascent and descent went extremely well. The climbing was easier than we both expected it to be; even the second of the three passes, which averages 9% for the last 9km, and gets up to almost 2,500m altitude (8,200 ft) was OK. We used a lowest gear of 24 teeth front - 26 rear, which allows us to use a cadence of about 80 even when doing just 9 kph / 6 mph. We entertained ourselves and our three companions with our new stereo system (iPod nano plus a basic battery-powered speaker pack attached to the stoker's bars). My stoker can also be quite entertaining herself:
The descents were a bit more chilly than the climbs (as you can see by our clothing change in the photo below). We touched 80 kph a few times, hitting 88 kph at one point (55 mph). Both rims stayed true and tight, no complaints whatsoever. It was nice to have the rear disc brake as well as the two rim brakes. We used all three intermittently, but the braking wasn't that intense because these major passes are fairly wide, generally straight roads (with some exceptions, as shown below). I think we would have been fine without the disc, but some of the more minor passes that we do require almost constant braking during the descents and then the rear disc is far more essential.
