I have a 1990 Burley Bongo tandem. I ordered it with the Arai drum brake. I replaced the self energizing cantilevers with Magura HS66 hydraulic rim brakes. These products are no longer available. You should never use sustained braking on a steep down grade. I use the braking technique called stab braking on my single going down steep grades. You firmly apply your brakes down to a lower speed. You then let up on the brakes and wait until you are at the highest speed you want to be at. then you do it all again. This allows the rims or disk to cool down. As long as some fool did not shave the cooling fins off of the Arai drum brake it was safe to apply it constantly on a steep down grade. There was a small startup of another drum brake. I think it was called a Madock or something like that. It resembled a shaved Aria. And that is probably why it did not make it. You are riding a tandem and you have more weight than a single and less wind drag than two singles. If you have a disk brake find the thickest rotor available. If you can afford it use better brakes. Paul makes the best mechanical disk brakes. The asian products cost less but are flimsy and weak.