It is true that the SLX took the place of the LX range that is now oriented towards Trekking bikes. But the SLX does not have the slightest connection with the LX derailleur generation. It is a new product that borrows the Shadow technology also to be found in the XT Shimano derailleur. The SLX sprocket derailleur pretends to be a component designed for those living on tight budgets, yet seeking high quality and optimal functionality.
We can say that, in broad lines, the Shimano SLX derailleur achieves some of these goals. In the first instance, its performance can be felt due Shadow technology: thanks to it, the derailleur no longer exceeds the chain stay plane, thus reducing the risk of being hit. The design is also very close to that of the Shimano XT derailleur, but the materials used for the SLX are not up to very high standards, being a medium range product.
The cage, along with other components, is made of steel and contributes to the weight of the SLX, but the 260 grams keep within the limits of decency. As for sprocket shifts, they occur more rapidly than in a Shimano Deore but a bit slower than a Shimano XT. A positive aspect of using Shadow technology is noted on uneven ground: the derailleur runs more quietly and you are spared the bumps of the derailleur hitting the frame.
Shifting under load is acceptable in terms of speed, but quite noisy. Another problem that I found with the Shimano XT can also be noticed with the SLX: after long periods of operation in dusty conditions, it requires small adjustments. This is not something so serious, especially because the SLX derailleur is pretty strong and makes small adjustments be only details.
In conclusion, the SLX cuts a figure for both forest trails and mountain paths. It is an ideal derailleur for beginners who are starting to take seriously the Cross Country Racing disciplines, designed especially for riders living on tight budgets. If its weight is not a decisive factor, you can opt for the SLX smoothly: it is durable and cost less than a Shimano XT, but approaching it in terms of performance.
Weight: 260 grams