The trail and enduro crowd have seized the new 650b wheel size with enthusiasm. It faces a harder fight for acceptance in cross-country circles however, where 29ers have proven their speed-sustaining advantages.
Frame and equipment: lighter side
Interestingly, 650b (or 27.5in wheel) bikes face a lot of the same challenges 29ers have increasingly evolved solutions for already. 29er frames and wheels are now so light that even the lightest 650b kit is only a few grams less – so far, anyway. That said, Norco’s new sub-kilo Revolver 7 frame is a featherweight by any wheel-size standard.
According to the Canadian company it’s the lightest and stiffest frame it has ever produced, and even in this mid-level ‘mostly metal’ component trim, it’s still only a fraction over the 10kg mark. Its ballistic-speed friendly weight is matched to a stealthy matt black aesthetic to create a bike that lines up for any race with a look of suitably murderous intent.
The matt finish provides a stealthy and sinister appearance
While the sleeve-jointed ZTR Rapid rim isn’t as light as the aftermarket version – which is welded – it’s still tubeless-ready, and converting will further increase traction. Going tubeless will also take some sting out of what’s undoubtedly a thumpingly stiff rear end – it’s much closer to a 26er than a 29er for rider comfort.
The choice of unapologetically firm Prologo saddle and super-light silicone grips as contact points further confirm this is a competition rather than comfort-focused machine. That’s fair enough, as if you’re looking to skim off a lot more staccato trail abuse – and don’t mind a little less immediacy – Norco has its larger-wheeled Revolver 9s.
The unashamed performance focus doesn’t mean the frame is pure utility. The gear cables and brake hose feed into the headtube and exit at the chainstay ends via neat, moulded ferrules. There’s no direct-mount front mech plate so it looks clean running a single ring, and the little bolted seat clamp is neat.
SRAM’s stripped down X01 transmission is a perfect ally for such a punchy bike. It saves a ton of weight compared with double ring designs and makes next gear selection blissfully simple. Yes, the alloy cockpit and seatpost could be carbon to save weight, but most similar price, similarly framed bikes run alloy finishing kit too.
SRAM’s X01 transmission is perfectly suited to this bike
The one obvious specification downgrade is the RockShox Recon fork, rather than a RockShox SID/Reba or Fox item. Its hollow-bottomed leg and alloy crown/steerer mean it’s not as heavy as it could be, but it’s still chunky for an otherwise light race machine.
It’s good to see a 15mm Maxle thru-axle though, as it makes a big difference to steering accuracy and means you don’t have to upgrade the hubs from quick release if and when you upgrade the fork.
Ride and handling: twists in the tale
As soon as you press the pedals you realise Norco’s claims about the stiffness of the rear end and bottom bracket are no idle marketing dream. Drive is delivered along the chunky stays and through the 142x12mm thru-axle-rear wheel with undiluted strength. Combine this to that low mass and minimal rolling resistance from Schwalbe’s hard Racing Ralphs and the Revolver is seriously quick on the draw.
In comparison to a similarly specced 29er, these smaller wheels and shorter spokes have less inertia to overcome and greater stiffness. This creates a real acceleration advantage when you’ve only got space for a few pedal strokes on technical trails, and the Revolver’s direct connection makes it easy to temper torque if the hard compound Performance semi-slick rear tyre slips.
The Revolver is an immediately engaging, enjoyable and fitness-flattering ride
So why not stick with 26in? We’re still surprised by how much more traction there is from a 650b tyre over an identical 26in one. While it definitely requires some skill, it’s perfectly possible to nurse even this skinny rear tyre through the deepest slop, and reap the fast-rolling rewards elsewhere. A set of chunkier tyres is still a wise move for regular mud-plugging, of course.
While the fork is relatively stiff and the 700mm flat bars/mid-length stem give a reasonable amount of control leverage, there’s some flex in the front end of the frame. You feel it as slight twist as you enter and exit corners, but it’s easy to adapt to and often flattering on tyre traction. It does undermine the tight-terrain response advantage of the 650b wheels compared to 29ers though.
The flex becomes a more meaningful problem at high speed. The Revolver can shimmy noticeably, and clipping a rock on fast and loose sections can get the front and rear halves of the bike flopping about with a distinctly disconnected feel.
The TK damper doesn’t need many rocks in its path to feel rudimentary and ragged by comparison with more sophisticated control circuits either, and surprisingly for such a race-focused bike there’s no remote lockout either.
It’s certainly not the first cross-country race bike to get nervous on rough, difficult terrain though, and less aggressive descenders who tend to focus more on climbing will find the low weight offsets handling traits they rarely ride hard enough to provoke.
In summary there’s no denying that Norco’s Revolver 7.1 is a seriously light, direct, stripped-for-speed race weapon. It’s one with a mostly-decent spec and a murderous aesthetic to match, too. Nevertheless, the below-par fork and obvious fore and aft frame twist undermine its truly aggressive racing potential in a very competitive category.