Jenni and I climbed Mt. Ventoux in 2004, up from Bedoin and down into Malaucène, where we were staying. It was the day of a Dauphine time trial stage up the mountain, so there were plenty of spectators. Had spectacular weather and climbed non-stop from Bedoin. As I remember, it took us almost exactly twice as long as the top pro cyclists (Lance among them.) Dunno what the spectators were saying, but we got plenty of comments. IIRC, we saw only one other tandem among the hundreds (thousands?) of cyclists heading up the mountain that morning. We had only standard reach caliper brakes on our Bilenky and experienced no brake-related issues on the descent. We did stop once not far from the top to let the rims cool, because we were stuck behind a line of cars who were all leaving the mountain when we were. Once traffic cleared, we didn't have to brake very often. Yes, it probably helped that our combined net weight (i.e., buck naked) was/is only about 270 lbs.

Definitely something to put on your tandeming to-do list, though I can imagine that it's not as much fun on a cold and windy day.

Regards,
Dave