Question: when is a hardcore hardtail not a hardcore hardtail? Answer: when it's a 'trail' hardtail.
That's how Marin have classified the B-17. More jumpy than the Kona Hoss but less burly than the Gary Fisher Bitter, the B-17 probably best represents what more and more riders are doing at the weekends: just messing about on their bikes.
Beneath its fashionably understated matt grey paint, the B-17's frame incorporates some interesting and unusual tube profiling. The coffin-profile down tube and slimmer - but similarly multi-faceted - top tube head up the B-17's intriguing plumbing. From an engineering point of view there's no proof that such complex tube profiles offer any significant weight, strength or stiffness advantage over good ol' round tubes - but they certainly look good.
Complex external butting on the head tube and twin open-ended gussets up front provide extra crash protection around this vulnerable area, though the overall effect is still noticeably less overbuilt than any of the other three bikes on test.
The plain Jane round seat tube is the only part of the frame not to receive a convoluted geometrical makeover. Bringing up the rear, triangular-to-round section curvy stays plug into large, airy cantilevered dropouts, while forged, airy and rather technical-looking braces take the place of the usual tubular bridges. The whole lot is put together in a format that's compact but deceptively roomy, combining - in theory, at least - crosscountry efficiency with a little freeride-inspired manoeuvrability.
Holding up the front and pointing the front wheel in the right direction is 130mm (5in) of RockShox Tora fork. It isn't anywhere close to the top of the RockShox family tree, but it performs very nicely indeed for the money. Adjustable rebound damping, a plush action and reasonably stiff steering make for a fork that just gets on with its job without ever bothering the rider. It's all we could ask for at any price, let alone for less than £700.
With a spec that balances cross-country functionality with a hint of freeride lite aspiration, the B-17 strikes about the right balance. Hayes' ubiquitous Sole brakes provide plenty of stopping power on demand; an SRAM transmission shifts slickly and makes a change from Shhyou- know-who; Truvativ cranks boast all three rings for ride-all-day versatility.
Wide, wide riser bars and a stubby stem prevent all this cross-country-biased functionality from becoming too stiffbacked and speed-obsessed, although the narrowish rims probably wouldn't make the best home for tyres much wider than the ones fitted as stock.
Cross-country riding in the UK has changed over the past few years, and it's bikes like this - at least as much as the new breed of long-travel enduro full sussers - that are helping to drive that change. Whether it's down to crossover from the world of freeride, the surge in popularity of short-loop man-made trails, or simply an urge to have more fun, bikes like the B-17 are enabling trail riders to discover the wild child that lurks within.
Quite simply, the B-17 is a little bit of everything to all riders. There's an efficient riding position, courtesy of a top tube so roomy that even the most flatbacked of XC racers are likely to feel comfy. There's stable but very placeable steering, thanks to a stubby stem and wide riser bars. There's a confidence inspiring acre of space above the top tube for unscheduled bailouts or scheduled airtime (and, for the pedantically-minded, a lower overall centre of gravity).
And there's more rock-swallowing travel on tap up front than most riders are likely to need - enough, certainly, to embarrass the Kona and allow the Marin rider to pull out in front on fast, rocky sections of trail.
It would be all too easy for this kind of approach to result in a bike that's averagely OK in a lot of situations, but not particularly brilliant at anything. The ace up the B-17's sleeve is that, in spite of some apparent limitations - that short stem, for example, or its overall weight, both of which should make climbing a pain - it's quite simply a whole bundle of fun in just about any trail-riding scenario you care to throw its way.
Few bikes add a whole new dimension to riding the same, familiar old trails. This is one. It might not have the invincibility or burliness of some tougher bikes, but for most riders, most of the time, the B-17 is about as much fun as two wheels, a frame and a bunch of components could possibly be.