Here's the second tranche of the 2007 Shimano XTR announcements - we covered various transmission bits a few weeks back, now we're looking at brakes.
The brake calipers will be available in two flavours for IS and post-mount systems. They're fundamentally not all that different from the current items, using two opposing pistons and forged monobody construction. The biggest change is with the brake pads - they have titanium backing plates, said to allow better heat dissipation and a solid brake feel. Resin or sintered pads will be available, and Shimano claims that the lifespan of the resin ones has been improved by 50%. That'd certainly be a welcome development.
One of the criticisms levelled at Shimano brakes has been a limited choice of rotors. It's hard to fault XTR on that score now, though - there'll be 160, 180 or 203mm options for front and rear, plus a teeny 140mm rear rotor for the weight weenies. All the rotors use Shimano's Centerlock system.
Claimed weights are 961g for a full set of brakes (front and rear) with 160mm rotors and Dual Control levers, or 735g with separate brake levers. XTR's Rapidfire Plus shifters are claimed to weigh 229g, which makes the two options only 3g different in total weight.
There'll still be rim brakes in the XTR group, although from the pictures here it doesn't look as if anything terribly exciting has happened to them since the last incarnation. The V-brakes have the familiar parallel link mechanism and cartridge brake pads. There's a separate brake lever or you can use the new XTR Dual Control lever for cable brakes.