Mountain bike sub-genres have consumed the entire industry. It's not just when you're buying a bike that you have to decide whether you're XC race, trail, light freeride or whatever; now you have to get the right accessories too.

Take shoes, for example. Most fall fairly obviously into one category or another. But not all. At first glance, you'd think that Specialized's Pro Carbons would clearly be full-bore race shoes - carbon fibre sole, ratchety strap thing, toe studs, impressive price tag and so on. But actually they're a little more versatile than that.

Traditionally, race shoes major on two things - stiffness and light weight. And a secure fit. OK, three things. We'll come in again... The Pro Carbons tick all those boxes, with a full-length carbon fibre sole, just-over-700g/pair weight and double-Velcro/single ratchet fastenings. The ratchet buckle has two mounting positions, which is handy for getting the fit just right.

Stuck to the bottom of the carbon sole is a suitably knobbly rubber tread, with threads for studs up the front if you need more grip on soft ground. Stuck to the top are synthetic leather uppers, with a reinforced rubber bit round the toes and a secure moulded heel cup. The usual mesh panels keep things cool.

So far, so conventional. But the really good stuff is inside. And no, we're not talking about our feet. Far from it. What sets the Pro Carbons apart is Specialized's Body Geometry gubbinses. The big S has loads of things labelled as using "Body Geometry Technology" - saddles, shorts, gloves, grips, pretty much everything that you wear or touch - but we reckon that it's in shoes that BG makes the biggest difference.

The most obvious feature is the "varus wedge". This cants the footbed slightly outward, which effectively straightens your knee out so it doesn't twist as you pedal. Then there's the "metatarsal button", a subtle lumpy bit under the forefoot that spreads the metatarsal bones. That's intended to stop nerves and blood vessels from being compressed as you pedal, reducing "hot spots", foot swelling and discomfort. Finally there's the raised arch support.

Specialized has all sorts of studies and graphs showing the performance benefits of BG shoes, but for us there's an obvious benefit - they're really comfy, and they stay comfy for a long time. There are plenty of race shoes out there that we'd rather not use for more than a couple of hours, but we've done full days with these and not been desperate to tear our feet out of them immediately afterwards. They're even not too bad to walk in - there's just enough toe flex to stop your heels popping out the back.

So what's not to like? Well, if you ride rocky areas all ratchet buckles are a bit vulnerable - we've not smashed these yet, but we've come close. They're replaceable, though, so it's just getting home that would be a problem. And they're a fairly frightening amount of money, although so far it looks like they'll last pretty well. Even so, if they're a bit spendy then fear not - most of the stuff we like about them also features in the more affordable parts of the Specialized shoe range...