Rick

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.

Carbonfiberboy 

On a tandem, one does "stab braking," alternating front and rear brakes, but mostly using wind checking, sitting up, knees out, etc. One can tell if a rim brake is getting too hot without feeling for the heat at all - a too-hot pad begins to fade. You'll feel it. The bike won't decelerate as sharply when the brake is applied hard. The cure of course is to stop ASAP and wait for them to cool. If they're not fading, they're OK. That's as I said above, with deep alu rims.

Rick

Stab braking is using both front and rear brakes to slow down then allowing them to cool before you use them again. Doing this allows you to never need to wait for a disk to fade or your pads to start melting. The drum brake and the rim brakes was the proper system. Weight weenies shaving the cooling fins off of the Aria and having some machinist attempt to startup a new drum brake without cooling fins or enough mass to take the heat has destroyed that option. Stab braking done properly will keep you from having a blowout on a tandem.

scycheng

I am well aware of "stab braking" called by different name other places. I do have a cantilever in the front which I do pulse and, yes, I can tell when the front rim gets hot.

I have an Arai in the basement. The reason I don't usually have it mounted when we tour is that unless we are planning transalpine route, it's an overkill. For "normal" CC touring on non-mountainous terrain, we just use a front rim and a 200mm rear disk brake.

Our tandem is made to accept front and rear cantilevers as well as rear disks. Rim brakes has 2 disadvantages for us on a tandem.

1. If the rim gets wet, it takes an extra eternity for the pads to grab. Being there. Done that. Just made the sudden T junction on a very steep road in Vermont. Good thing my SO didn't realize how close we came to ditching the bike hard.
2. Risk of heat related failures.

Disk brakes has it's own set of downsides so it's just a matter of making the tradeoffs. YMMV and I make no claim that our choices are better than yours.

Carbonfiberboy 

We also have a spare wheel with an Arai mounted. We never use it except for loaded touring in unknown terrain. V-brakes work fine for us riding in the mountains. Big downside for us with rim brakes is that we ride in the rain a lot and need to replace one rim every year due to wear, i.e. rims last 2 years. Yeah, it takes about 50' to wipe the water off the rims. Can seem like an eternity when the FedEx truck in front of you suddenly hits the brakes. But our frame has no disk mounts and we don't really want to go through the frame mod and repaint. In the famous tandem group coast-down on Mt. Ventoux, the rim brake bikes were the only ones not to have issues. There were no Arais (2 lb. penalty). Overconfidence and maybe lack of feedback. I know several rear disk bikes which have warped their disks, one that overheated - the bike went into the woods but was OK. Nothing's perfect except maybe dual disks with big laminated rotors. But there's the weight again, so kinda back to the Arai. Gotta get ride of the heat somehow. But disks are certainly potentially safer. Arais don't do what they do.

Rick

The Magura brakes don't take 50 or more feet to wipe the water off the rims. Some moron in heavy traffic and in the rain, brake checked me several times and I didn't hit him with my tandem.

That explanation was quite convoluted. A drum brake used to keep speed in check and rim brakes works the best. Disk brakes on a tandem are not adequate. Some of those riders had melted pad adjusters and warped disks and no brakes. There is more heat than they figured in the disk design. Or they just didn't care what the average riders skill level was. The Arais was not a weight penalty. It has more to do with available equipment at the time and in the case were the weight weenies shaved the cooling fins off and crashed IQ quotient.

ianbal

We are going with Santana to France in July and plan to ride Ventoux and have rim brakes. They won't let teams with rim brakes descend from the summit. Is my understanding of the above statement correct, that there were no issues with those teams that *only* used rim brakes?

Carbonfiberboy 

Yes. The rim braked bikes stopped to let their brakes cool. The others setups did not. I can understand Santana not wanting to be responsible for teams who may not know how to descend with their brake system. The descent I'm referring to was quite a while ago. Discs have gotten a lot better since then.

ianbal

Thanks for the information.

ridey b

What about drum or hub brakes

Monoborracho

When we spec'd our Seven Ti back in 2012, we specified cantilevers front and back with a rear disc also. (as late as 2016 one of the large tandem builders, the name starts with S, told us how unsafe a front disk was, particularly on carbon fork). We have brifters, the 6703 Ultegra tandem cranks -10speed, XT rear d/r.We used the premium Shimano cantilevers and never had any problem but I was never really happy either. I ran the disk with a bar end shifter on the right drop bar....worked great for "fanning the brakes" on long downhills. Then in 2017 while touring out in Solvang CA the front shifter locked up. I loosed the cable and we pedaled back from Los Olivos in the little ring. I was able to swap out stuff, move the barcon to the left and use it for the chain rings. I put the disc on the right brifter and its still there.

Next---when we got home I bought a set of Avid CX v-brakes that did indeed work with the brifters. Great action, great braking, WOULD NOT CLEAR MY FENDERS. (They are now for sale so anyone ?? let me know )This may not be an issue for many but we spec'd the tandem to run big if we wanted to. We run 40mm Schwalbe Dureme's on 48 spoke Paul/Velocity Dyads when we travel overseas. We run Spinergy's with 28 or 32's at home. I have now gone to a set of Avid V-brakes with travel agents like we had on our first bike. (By the way, front V-brakes are what the big S company recommended) The front is on a brifter, the back V brake is on the the bar end shifter (excellent parking brake also) and the rear disc is on the right brifter.

I'm really happy with this setup. And, the V-brakes are very simple to adjust when we change wheel sets.

ianbal

Not sure if this question was for me but Santana is allowing those with rim brakes that use drum brakes to descend.