Originally Posted by
Leisesturm
Was initially quite worried about the disk brake size because of the naysayers here but in two seasons in all kinds of riding except loaded touring I haven't felt the stock brakes to be in any way deficient.
I'm not sure if I was one of the naysayers or not. However, I believe when I have been asked about the disc-equiped Raleigh coupes I have noted that Avid, heretofore, had only approved the use of their 203mm discs as primary brakes on tandems.
While the lack of the manufacturer's endorsement doesn't mean the models with 6" rotors "won't work" for many teams, it does suggest that -- like all brakes -- they have limitations. To be fair, tandems with coaster brakes and antiquated center-pulls also "worked" when there wasn't anything better and under all different types of conditions.
Therefore, the decision to use any type of brake system on a tandem (as well as the rest of the components to include the frame and fork) is one that always needs to be tempered by the intended use and expectations of the operator. As someone suggested, if you plan to take on the Alps d Huez or other significant riding conditions, the braking system on your tandem would need to be a heck of a lot more robust than what you'd use for a Trans-Florida challenge, the hilly terrain around NYC, or other light to moderate riding conditions.