Originally Posted by
meanwhile
Cantis are quite different from the brakes that pro road teams use. *Very* different! Set-up right they are much more powerful - so much so that they feel "mushy and spongy" set up correctly because they squash the brake pad against the rim in a way that eg centre pulls don't have the power to do.
/snip/
Cantis are still the preferred stoppers for performance tandems - and these are bikes that need several times more stopping power than any other. At least one type of canti can brake a tandem fast enough to lift the 350-400lbs mass of bikes and riders using the front wheel as a pivot! That your brakes are cantis is not your problem.
Mark Abele at Rivendell, who runs cantis on all of his bikes and who Rivendell says is "the best cantilever brake adjuster in the land" said to me via e-mail that dual pivot calipers have superior stopping power to cantilevers. He said the sole reason to spec cantis is for fat tire and fender clearance.
So all this talk about the superior power of cantis is just hooey.
You can also do the math on the stopping power as well, but I don't feel like doing it right now. It's basic geometry and mechanical advantage calculations though.
Originally Posted by
meanwhile
Spending the money to have the frame modified and buy a new fork. Increase in weight. Two more unboltable components that a have thief attraction rating.
Discs are great but they have their drawbacks, and going to them just because you can't get a set of cantis to work properly doesn't make sense.
Also standard discs aren't compatible with standard cross/road brake levers. The OP would need a special model like the Avid BB7 ***Road*** Disc Brake, NOT the MTB version!
The OP said his frame is already compatible. He'll just need a fork. The Nashbar CX fork is a Winwood muddy without the label, and is highly affordable. I also fail to see the problem in your bold text, as the mechanical BB7 is a fine brake...so is the Shimano R505 road disc.
Originally Posted by
kenshinvt
Squealing, rotor bending/truing, aligning calipers to avoid pad rubbing, line bleeding (if hydraulic), weight, special forks & wheels, limited options for road lever compatibility, risk of locking out if you push lever with wheel off.
Don't get me wrong though, I absolutely love the power and feel of disc brakes. Just drives me nuts sometimes with the issues they bring.
Squealing is a notorious cantilever problem. A lot of the other issues you raise are for hydraulics, which doesn't apply here. And how is disc caliper alignment more difficult than the arcane art of cantilever setup?
As an aside, disc brakes don't have the cosine error that cantilevers do. This is a big plus in their favor.