Shimano's all-new 2007 XTR groupset won't be in the shops for a little while yet, but recently we had the opportunity to get a few hours in on late-prototype parts. The venue was Coed y Brenin, the conditions were dry, dusty and extraordinarily hot and the bikes were Giant Anthems set up in an almost rabidly XC race style - negative rise stems, flat bars, bar ends, short-knob tyres, the lot. Not necessarily our first choice of bike for the trails, but they acquitted themselves pretty well once we'd got our head around the old-school style. The main thing is that they provided a test bed for the XTR bits. Despite all being stamped or stickered with "Prototype" labels, the parts were all essentially production items. The finish was wrong, with most bits being too black - the cranks were as they should be, and everything else ought to match them. Appearance aside, though, this stuff was as it will be. So without further ado, let's dive in with some first ride impressions.

Crank overview

The new left-hand crank mounting arrangement

Titanium and carbon fibre middle ring

Caliper and rotor

Separate brake lever

Cranks

XTR cranks have always been the flagship of the group and the part that people aspire to. The 2007 cranks use an evolved version of the Hollowtech II outboard-bearing system, so it's kind of Hollowtech II.1 really. The main difference is the attachment of the left-hand crank. The end of the axle is still splined, but the often-abused pinch bolts have been dropped in favour of an alloy bolt that threads into the end of the axle. To preload the bearings there's a threaded ring between the crank arm and the bottom bracket cup - loosen a small bolt, snug the ring up, tighten the bolt again. This looks considerably more user-friendly than the old system and it's a bit lighter.

The other special feature of the cranks is the middle ring. In a bid to improve durability without adding weight, the ring uses composite titanium/carbon fibre construction. The titanium bit includes the actual teeth and the bolt holes, while the carbon fibre adds stiffness. It's claimed to last twice as long. The outer ring is styled to match, but it's all aluminium.

There's not really that much to say in terms of the ride - they don't feel markedly different from the old ones, not that that's a bad thing. If you're a heavy gear-masher then you might notice that the outer chainring is stiffer than the old one. The whole system is lighter than the outgoing one, but we're only talking about 30g or so. We particularly like the finish - the outer face is polished with deeply-engraved logos, so they should stay looking almost as new for ages, rather than gradually losing their anodising to shoe rub.

The demo bikes were also kitted out with the new XTR pedals. They're the first pedals to actually carry the XTR logo - Shimano has always kept its pedals non-group-specific in the past. The actual mechanism is the same as the existing M959 pedal, but is lighter and, we're told, stiffer. In use they feel exactly like 959s, which again is certainly no bad thing.

Brakes

There are some welcome changes in the brakes. The current generation of XTR disc brakes has always been pretty effective, but some tweaks have opened up various handy options that we rather like. The calipers themselves are still forged one-piece two-piston units, restyled to match the new group. They'll be available in IS and post-mount versions - the post-mount-and-bracket arrangement found on lots of other brakes is versatile but adds weight.

Sintered and resin pads will be available, both with titanium backing plates. The lifespan of the resin pads is claimed to be 50% better than the current ones, although a dusty Coed y Brenin clearly isn't the place to test that particular claim.

The choices start to open up with the rotors. They're a new two-piece design with an alloy spider, and rather than a choice of 160mm, 160mm or 160mm you can now opt for 160, 180 or 203mm at either end plus a tidgy rear-only 140mm if you're really keen to get the weight down. They're all Centerlock (although six-bolt rotors with suitable diameters can be sourced from other groups - you don't get the two-piece construction, though) to mount to the new hubs and wheels. The demo bikes had 24-spoke XTR wheelsets with Scandium rims. The most noticeable thing, though, is the new freehub mechanism - it's got a 36-notch pawl for quicker engagement.

For the first time there's also a separate XTR hydraulic brake lever without any shifters attached to it. There's a distinct layout resemblance to Magura's levers, with the inboard reservoir and tucked-in hose routing. That's no bad thing, though - it makes the levers compact and you can run them very close together if you're that way inclined.

The demo bikes were set up with 180mm front and 160mm rear rotors. And with the front brakes on the left... Sorting that out was the work of a few moments, although it's worth noting that bleeding the brakes if you're using the new Dual Control levers is a little more fiddly than with separates - the reservoir cover is underneath, so you have to turn the whole lever upside down. Once we were up and running, the brakes were impressive. The new lever (in both separate and DC configurations) is a pleasing shape, with a good hooky end. The feel is soft without being spongy and there's plenty of power and control. And we didn't manage to cook them, despite over-generous applications of brake. We were just doing that to see if they'd overheat, honest.

That's most of the bits. The obvious exception is the most interesting - the shifters and mechs. Stay tuned, ride impressions on those are coming up shortly...