Shimano Releases '07 XTR Cranks, Front Derailleur
JUNE 02, 2006 -- IRVINE, CA (BRAIN)—Release of XTR’s FC-M970 crankset and FD-M970/M971 front derailleurs make the ’07 XTR group complete. Shimano gave the public a sneak peak of ’07 XTR wheels, XTR branded pedals, rear derailleur and shifter prototypes at Sea Otter and trickled out other components about a month later.
Shimano’s Hollowtech II cranks are for many riders the best cranks bar none, even if they are the only Shimano equipment they ride. For ’07 the company improved the design further. It got rid of the pinch-bolt on the end of the left crank arm and tapered the end of the bottom bracket axle. The left crank is now bolted on and a threaded adjusting nut system on the inside of the arm adjusts bearing play. The new system saves weight—about 40 to 50 grams. More importantly, it allows a rider to micro-adjust bearing play for better feel and longer bearing life.
“Our old system was like a threadless headset, you just compress it until there is no play and say that’s good enough to ride. The new adjusting nut allows you to trim just the right amount of bearing play by hand,” said Devin Walton, of Shimano’s media relations group. Walton is mum about whether the system will turn up on Dura Ace, but he did point out that M960 XTR crank technology was used for current Dura Ace.
Excessive middle chainring wear is a headache of current XTR. Shimano addressed this on the new middle chainring by combining titanium teeth and carbon fiber ramps. Walton expects the new ring to have double the life of the current rings.
“We actually mold and machine shifting ramps into the carbon fiber. The carbon makes the rings much stiffer, which contributes to their durability, and it is smoother and much quieter then all metal rings,” he added. A new nickel coating for the outer chainring should provide up to four times longer life over the current ring, and unlike current XTR, M970’s chainrings will fit XT and LX cranks.
The front derailleurs build on the wide rigid pivot design debuted on the M960 derailleurs, but the company switched to a multi-clamp variable cable routing design. “We had resisted doing this because it adds a bit of bulk, but it is one of the most requested changes. So we worked hard to keep the look of the derailleur in keeping with what people expect of XTR,” Walton said. Size specific M960 front derailleurs will remain in the line as long as there is demand for them.
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