Smoother, lighter, prettier. The new 2008 Shimano Deore XT RD-M770 Low Normal rear derailleur is taking its design cues from XTR, with a slightly bulkier X as the outer cage plate. After debuting a re-designed XTR this past fall, XT is doing what it always does, slowly closing the gap between the two. If you're partial to XTR, you're probably a little disappointed that XT is starting to look much like it's high-zoot brethren. If you don't want sacrifice as much cheddar as XTR demands, you're happy that XT is on the march.

As some of our bikes seem to be mud-catchers, we like the more open design. Muck does get in, but it also comes out. The black ano' pieces hide the dirt as well as confuse some as to whether or not it's megabuck carbon. It isn't, but we're not telling.

Low-normal refers to the spring tension in the derailleur pushes the cog up to the taller or easier cogs. Aka "rapid rise," many think this is good for people who spend a lot of time climbing in their granny ring. While it is designed to work with the XT Dual Control shifter, it also can work with XT Rapidfire shifter, though it will reverse the direction of the shifting.

The Shimano Deore XT RD-M770 Low Normal rear derailleur is offered in two sizes: GS (mid-cage) and SGS (long-cage). In all cases, the max cogset that can be used is an 11-34. The difference is that the mid cage size has a 33 tooth total capacity while the long cage takes 45 tooth total. All XT rear derailleurs have sealed 11-tooth upper and lower jockey wheels. The spring in the derailleur yields Shimano's traditional "light action" gear changes. 239g (long cage). MSRP $109.99.