SRAM X.0

For years and years Shimano basically had the mountain bike transmission market to itself. SRAM had been nibbling at the edges, first with Gripshift and later with ESP shifters and mechs. But it was the eventual launch of its trigger shifters (after the odd false start) that really put SRAM on the map. And the release of its top-end X.0 components definitely put the cat amongst the pigeons. Suddenly SRAM was the brand of choice for anyone putting together a super-high-spec bike, and that included bicycle product manufacturers. We rode a bunch of bikes at last year's Interbike trade show, and nearly all of them had X.0 on. It's certainly no exaggeration to suggest that the presence of X.0 is at least partially responsible for many of the features found in Shimano's forthcoming 2007 XTR groupset - Shimano is still dominant across the broader market, but it's certainly been rattled in the high-end.

But is it all just hype, or is X.0 really the dog's danglies? We've been running a rear mech, shifters, PG990 cassette and PC991 chain for several months now, including some sorties into quite monumentally horrible conditions. So how's it doing?

The selling points of X.0 are many and various. The first is the concept that SRAM has been pushing since the early ESP days - a 1:1 actuation ratio. This means that the lever pulls more cable, which results in lighter shifting effort and increased tolerance to grimy cables, both welcome things.

Both shifters and derailleur share a funky polished alloy/carbon fibre look. We've been using the mid-length derailleur, which has carbon fibre cage plates - the current long-cage model has aluminium ones, but they'll be carbon too for 2007. Cable routing is the direct, almost-straight-line style that SRAM acquired when they bought Sachs's rear mech project several years ago - no big cable loop, less drag but very occasionally awkward routing on some frames. And you don't get a barrel adjuster on the mech, so you have to make adjustments at the shifter.

All the fasteners are titanium to cut weight, although the differences between the X.0 mech and the obvious rival - XTR - are fairly small. A medium X.0 mech is claimed to be 6g (count 'em) lighter than the current XTR offering, while 2007 XTR is - perhaps not coincidentally - claimed to be exactly the same weight.

The shifters are the really interesting part, though. After all, they're the bit that's really helped SRAM make an impact. And with good reason - they're great. We're big fans of braking with our index fingers, which makes SRAM's "all thumbs" shifting ergonomics particularly welcome. The big lever underneath does downshifts, while the release lever clicks upwards to perform upshifts. Shifting in both directions is super-fast, helped by the minimal backlash in the system - you don't have to move the lever very far at all before the mech starts to move.

SRAM makes a big thing of the adjustability of the X.0 shifters. The most obvious adjustment is the shift lever angle - loosen a pinch bolt and you can rotate the lever through a 30° range. This effectively lets you choose between a slightly harder to reach lever but with easier multiple-cog shifts or to trade off shifting across half the block at a time for a right under-the-thumb start position depending on your preference. You can also mount the shifter on its clamp in two different positions to tune the relationship with the brake lever, or even mount it outboard of the lever if you so wish. Again, it's notable that these latter features are also found on Shimano's 2007 XTR Rapidfire+ pods. The X.0 triggers are significantly lighter than the "current" XTR RF+ (which are actually an earlier generation of component than the rest of the group) at 225g vs. 259g. The 2007 XTR lowers the bar again, though, at a claimed 215g.

We can't get all that excited about cassettes and chains, although the PG990's red anodised lockring and spacers are pretty cool, as these things go. It's a bit heavier than the XTR equivalent (largely on account of not having any titanium sprockets) but also considerably cheaper (largely on account of not having any titanium sprockets).

The main thing, though, is performance. And it's really very, very good. It's light in feel without being vague - you always get a click to let you know that you've done something - always accurate, fast and it hasn't missed a beat even through proper filth. We haven't even managed to sieze the jockey wheels up, which is something we've done on pretty much every other SRAM mech we've encountered. So top marks there.