2007/05/02

25 anniversary of true mountain bikes



In 1982, Shimano introduced the first ever dedicated mountain bike groupset with their Deore XT parts... 25 years later, the new XT group is released and you can see how much mountain biking has changed since, but also changed road cycling by pioneering many technologies that has trickled down on the road. The latest version of the real do it all group (XT works as well as XTR with only a slight weight penalty, not as impressive finish but at a much cheaper price) seems like a great one, here are some interesting points.



There is a new rear derailleur version called The Shadow that is a whopping 15mm lower profile. It protrudes much less to the right of the bikes and sits closer to the cassette to avoid being damaged by rocks and other regular trail obstacles. The low and high normal derailleurs are still available. front derailleurs have redesigned cages to allow more clearance for the bigger tires many are now using and have angled adjusting bolts for easier access on many full suspension frame designs.


Also worth noting is the new brakes. They feature what Shimano calls servo wave technology. That means a non linear travel of the brake pads relatively to the brake levers. The begining of the lever's stroke pushes more fluid than the later part of the stroke. That means you gain more clearances between the pads and rotors so alignment and rotor trueness is not as critical to get a rub free brake system as it normally is. When hitting the lever, the pads move toward the rotor much faster for instant braking even with the added clearance but then travel more slowly vs the lever to still provide good modulation and controlled power. Marvelous! I'm just wondering why they didn't do it before, I was wondering why it wasn't designed like that last time I replaced rotors and re aligned my calipers last summer... Does it mean the end of truing rotors and fine tuning caliper alignements? Maybe not completely but it should make the process much easier.


We get 2 new wheels, a lightish XC wheelset with 19mm of internal rim width, butted spokes and quick release hubs and a heavier duty wheelset with 23mm rim width, straight gauge spokes and a through-axle front hub. Both sets have 10 degree engagement freehubs, 24 straight pull spokes, red alloy nipples, 'look at me everyone' graphics and are disc only of course, rim brakes died a while ago if you hadn't noticed.


The new XT Dual Control shifters, even though they should work great, win the prize of the ugliest bike component ever produced by the japanese company.


The new crankset has a thicker big ring and a drilled carbon and steel middle ring to help improve strength and durability.


There is a pair of XT pedals but they look just like the same old, heavy and crappy SPD-M540 pedals.


The cassette now has retaing pins to prevent the chain to go and chew into your spokes just in case you didn't tune the rear derailleur properly.


The new group should be available in July.

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