David Damerell wrote:

Quoting Mark Hickey :
David Damerell wrote:
You cannot have more braking than that, so the theoretical brake "power"
(which tandems find out, with surprising results) is quite irrelevant.
An interesting (to me, at least...) data point is that I designed my
new tandem around regular road caliper brakes, never having been
really happy with the performance of canti brakes on my previous
tandem.

Certainly plain ordinary calipers can work just fine, but did you try
fiddling with the straddle cable? I've got it as high as will just permit
me to bottom out the lever (higher, and you're just getting lower
mechanical advantage; lower, and the input force is lower, as I'm sure you
know) with maximum grip, and the front brake is certainly good enough to
produce an alarming DOING sensation from the front fork...

I've set up the rear canti brake on my old Santana many times, looking
for adequate braking. As you mention, the "sweet spot" is with the
straddle low enough to produce good mechanical advantage, but not TOO
low. Going to the DiaCompe 287 T (?) lever (slightly longer pull)
helped a bit, but the real improvement came with a set of solid
straddles. There's just not enough extra pull in a typical road brake
lever to overcome even a little straddle "give".

But even so, the caliper brakes I'm running now (Campy Centaur dual
pivots) are head and shoulders better than I ever got the cantis...

[The back brake's a Suntour self-energiser, so I've no idea how well a
conventional canti works on a tandem.]

That's probably the one place that self-energizing brake makes sense
(since the back end of a tandem never gets TOO light under braking -
I've yet to see anyone do a nose wheelie on one). ;-)

Mark Hickey
Habanero Cycles
http://www.habcycles.com
Home of the $795 ti frame