« on: May 15, 2014, 09:18:40 pm »
The rim vs disc brake debate is still raging and can get pretty heated at times. It's almost as bad as the Shimano vs Campy arguments of the past.
So this is MY opinion and MY take on brakes. Others can (and will) chime in with agreement or disagreement as they wish.
Bicycle stopping distances are not limited by their brakes but by their tire grip and the tendency of the rear wheel to lift under hard braking so claiming one form of brakes provides better stopping then others is misleading. Any decent rim or disc brake will lock both wheels quite nicely. So the main differences are:
Disc brakes may work a bit better in the wet but good rim brakes with good pads are very close behind. They are also a bit better at heat absorption on long downgrades and keep the heat away from the tires. However, they can be overheated if used poorly just like rim brakes.
Disc brakes don't cause rim wear and this can be a consideration for true off-road MTB use but road rims last a long time anyway.
Disc brakes complicate and slow wheel installation and changes. Probably not a big issue until you have a flat in the rain as it's getting dark.
Disc brakes are heavier and their frames and forks are heavier as they have to be reinforced to take the braking forces and discs are less aero but these are all mostly non-issues with a touring bike.
Front disc brakes used with standard downward facing fork dropouts tend to eject the front wheel under braking forces. It is ESSENTIAL that a fork with good "lawyers lips" AND a strong internal cam (Shimano or Campy type) quick release skewer be used. Some fork designers have adopted either front facing dropouts or, better yet, through axles to avoid this problem. The Disc LHT seems to have standard fork dropouts so I assume they have substantial lawyer's lips. If you go that way keep the qr skewer TIGHT.
Mechanical disc don't have the modulation or ease of operation of the better hydraulic models but they make it up in simplicity and ease of repair.
To me disc brakes on road and touring bikes are still a work in progress and I expect developments in the future will make them more user friendly.