The new XT — plenty of choice for 2008
In 1981, Yoshi Shimano, president of Shimano's U.S. sales office, noticed a weird new segment of bikes popping up in the U.S. bicycle market and immediately informed corporate headquarters in Japan that Shimano needed to be a part of this new "mountain" bike movement.
The new BL-775 brake lever incorporates Servo-Wave technology
XT turns 25 this year, and to commemorate the occasion it gets a facelift for 2008. While many of the improvements trickle down from last year's revamp of XTR, there are a couple of brand-new technologies in the mix.
"This is an adventure group in the sense that it's designed to be as contemporary as possible in its focus," said Devin Walton, Shimano's PR manager
The ST-M775 Dual Control lever does as well, both feature radial master brake cylinders.
"That's why you're seeing an even wider range and additional options over even what XTR offers. Options are sort of the result of XT's initiative of just being contemporary."
What's old is new again
When it was introduced in 1992, Servo-Wave was a mechanical cam-operated method of changing the XT brake lever's cable-pull ratio throughout the lever's stroke. The design started with a high ratio of cable pull to lever movement, then progressively reversed the mechanical advantage, providing more braking power. In addition to providing powerful braking control, the new system also permitted more rim clearance.
Shimano’s new RD-772 is called the Shadow rear derailleur for its narrow profile.
"The reason for even integrating the Servo-Wave is so that you can get the maximum amount of lever travel and leverage to get the most power," said Walton. "It's a blend between those two.
"What the Servo-Wave does is that it gives your pads clearance, but it moves the pads quickly through the first little bit of motion so the pads will contact [the rotor] as quickly as possible, and that's what allows you to get the most power out of the system."
Shimano’s new HB-M776 20mm XT hub hub can be purchased alone or in complete wheelset.
The XT group adopts XTR's goal of providing choices for all types of riders. Most apparent is the new Shadow rear derailleur, which is new to Shimano's mountain line and meant as an option for technical-trail riders.
The Shadow is based on the top-normal (standard style) spring design. Main features are a slender side profile (15mm narrower than a standard XT derailleur) and a redesigned mounting bolt and B-spring assembly, with a stronger spring, that work together to prevent the derailleur from knocking into the underside of the chainstay on FSR and other suspension designs. Traditional top-normal and low-normal rear derailleurs will be available as well. All three styles come with a choice of medium or long cages.
The new FC-M770 Hollow Tech II crank has a carbon reinforced steel middle chainring.
The XT rear hub is also upgraded with two extra pawls to quicken the engagement response time. The hub boasts a 10-degree engagement, twice as fast as the old version; it, too, relies on adjustable angular contact bearings. The rear hub has a new 14mm 7075-T6 aluminum axle. A standard quick-release wheelset will also be available. It features a narrower (19mm I.D.) rim in line with cross-country and racing applications.
The new XT cassette has pins that extend rearward to catch a chain before it damages spokes in the event of an over shift.
In the trickle-down category XT's drivetrain incorporates instant and two-way release technologies from XTR. This year's XT transmission featured two-way release shifter technology but not instant release. Instant release lets cable go on the push or pull stroke instead of waiting for the lever to return, while two-way release allows the cable release trigger to toggle for both push and pull operation.
The front derailleur features angled limit screws and a lighter cage with more tire clearance for use with tires sized 2.3 inches and above. It's available in three versions: E-Type and top and bottom swing. Both the top- and bottom-swing derailleurs come with one band size and use adapters to fit 28.6, 31.8 and 34.9 seat tubes.
The XT PD-M770 pedals look like XTR except for their logo and powder coat.
In final touches, Shimano added external pins to the rear cassette to catch the chain in the event of an over-shift and protect the rear wheel's spokes. The XT also group gets its own branded 352-gram PD-M770 SPD pedal.
The components should be available by mid-June.