The Shimano Deore rear derailleur was radically amended in 2010. The changes are both technical and aesthetic. In terms of functionality and the technology used, the new Shimano Deore now uses the Shadow technology, like its elder brothers from the XT or the XTR range. Shadow technology refers to a new position and mounting of the derailleur to the hanger bolt and the fact that it no longer exceeds the chainstay plane, whether it is placed on the small or the large sprocket. Thus, the chances of it being rammed by a root during a crazy race are very small. The offer also includes the non-Shadow model, for a slightly lower price.
In terms of appearance, the new Deore scores high again: it makes the former Deore look like a 10 years’ old derailleur and seems to be much better put together. You can figure out all these things when going over a curb or make bigger jumps. It is not as quiet as the Shimano XT Shadow, but it does its job much better, considering that it is a component that ranks in a mid-level league, but scores below the Shimano SLX.
The chances of rear derailleur hitting the frame are now smaller, reduced almost to zero. In terms of functionality, it shifts better and is quieter than the old model. Shifts are more accurate and a little bit faster. Although I would have preferred a shorter cage, I can say that the longer one also does a good job; therefore, such a configuration can be used for Cross Country disciplines.
Compared to the old model, it is clearly better. Compared to today’s components, the weight is acceptable (less than 290 grams). Its direct competitor, the Sram X.5 (2010), has about 20 grams more, so the Deore rear derailleur manages to surpass it in this aspect. It is still provided with a cage made of steel, which holds good for most components, including the hanger bolt.
Though it shifts much better than the previous model, I am not convinced it is a rapid derailleur. It does a good job, but without much refinement. This is but a normal thing for class entry-level to medium. I recommend it both for Cross Country and Trails and, with very small reserves, for All Mountain.
Weight: 280 grams