For approximately for ever, Shimano's MTB groups have been for mountain bikes. Obvious, yes, but the point is they've never really made much of a distinction between different sorts of mountain bikes. Which is fair enough, for years there weren't different sorts of mountain bikes.

These days, though, it's all sub-genres and little tribes and things. It was inevitable that Shimano would start being a little more specific, and the new Saint semi-group is the first example. This is the stuff that you may have seen referred to as XTX. Heirarchically it kind of slots in between XT and XTR, but while XT is your everyman all-round trail riding gear and XTR top-flight race kit, Saint is for heavy duty applications like riding off cliffs.

It's not a complete set of components - there won't be Saint shifters or brake levers. But all the bits that have different requirements are, well, different.

The most obvious is the crankset. The old XTR cranks were popular amongst downhillers who wanted something strong without the heft of three-piece chromoly cranks, but they still weren't designed with ultimate strength in mind. The oversized Hollowtech II (the same integrated axle/outboard bearing system as seen on 2003 XTR) cranks are said to be twice as strong as XTR and considerably lighter than three-piece cranks. You can choose from one, two and a bashring or three chainrings, although there's no chain device so you'll have to make your own arrangements.

Next up is the wacky rear derailleur. It uses a direct axle mounting and is designed not to break or damage the frame in crashes. The design also gives frame makers rather more flexibility in dropout design, as they won't have to get a gear hanger in the right place.

Saint hubs use a similar Centre Lock disc rotor mount system as XTR, only bigger. Bigger because the front hub is Shimano's first 20mm through-axle compatible unit. The rear hub is oversized too.

Finally there are the disc brakes, with XTR-style one-piece two-pot callipers and rotors in 160mm or 203mm sizes.

That's all we have at the moment - more information as it becomes available. Saint should start to trickle on to the market in October...