FOUR heat-related blow-outs in one trip: WOW! With an Aria drum brake: double WOW! I want people to know that this is not so typical.
We live in Switzerland, and have been riding our Co-Motion Speedster in the Swiss, French, and Italian Alps for four years, including on some of the steepest, longest, twistiest descents around. Often unladen (team weight is 280-300 lbs), but sometimes with full camping and touring gear (maybe 50 lbs of gear). In all that time, we've had ONE puncture that was definitely heat-related (front wheel, part-way down a serious Alpine pass, but on a straight section, so luckily we were able to bring the bike to a stop safely), and one other puncture that I believe was caused by heat, but I'm not certain (this one was in the city, again front wheel, but it was when we had already slowed down and so was easy to control). This is in probably 10-15,000 km (6-9,000 miles) of riding and more mountain passes than I could count or remember.
Braking setup is two Avid SD7 rim V-brakes plus an Avid BB7 rear disc (203mm). The stoker controls one of the rear brakes, which was originally the disc brake, but is now the rear rim brake. We've also done some (admittedly less extreme) riding without the disc when we were having some problems with it.
Admittedly, we're both pretty experienced and confident descenders, so don't ride the brakes that much and let the bike run as much as possible between the corners. Sitting bolt upright, with knees and elbows sticking out really helps as a fourth, air brake.
Having said all that, based on our experiences of riding Alpine roads on the tandem and single bikes, there are certain roads that we will NOT take the tandem to, and would instead use the single bikes purely because the descents are too tricky on a tandem. These would include Grosse Scheidegg (both sides), the north side of the Nufenen, the west side of Pragel Pass, and the south side of Moosegg (we did this once on the tandem and had to stop halfway down to let the rear disc cool off after it faded quite significantly). If your four punctures were on those four roads, then I would not be that surprised. For comparison with roads other people might know, we've done the Alpe d'Huez descent on the tandem before and wouldn't hesitate to do it again - that was fun (not overly steep, nice and wide, pretty straightforward between the switchbacks).
Last edited by Chris_W; 10-16-12 at 11:32 PM.