Calibre’s Bossnut has been the boss of the entry-level full-sus market for several years now. Its success is partly due to modern geometry and angles that perform at many speeds on a range of trails, but it’s also down to Calibre ensuring that the parts don’t let the side down in any crucial areas.

Grippy tyres, quality damping and frame durability, enough braking power and an efficient wide-range drivetrain tick all the boxes.

The pricier Triple B version tested here adds a dropper post, brilliant SRAM Guide RE brakes and a more sophisticated fork.

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Calibre Triple B frame

The latest-generation, hydroformed aluminium Bossnut is significantly slicker-looking and curvier than its predecessor.

While the 6-series alloy frame still has 130mm of travel, the suspension is now a bit more sensitive, due to a rearrangement of the linkage anchor points and a well-tuned RockShox Monarch RS shock.

Its Grip, rider position, frame stiffness and suspension action are comparable to those of some more expensive machines.

Mick Kirkman

New geometry helps too. For 2020, the Triple B has a slacker head angle (65.5 degrees in a large) for more stability at speed and a steeper seat tube (48cm / 18.9in) for a better climbing position. Both are surefire performance enhancers that feel great on the trail.

A 142x12mm bolt-thru rear axle combines with fat tubes, a beefy rocker link and thick stays to give a stiffness boost that’s very welcome as soon as you realise that the Triple B doesn’t ride like any other budget bike out there.

Calibre Triple B kit

It’s rare for bikes costing even masses of cash to not have the odd bit of questionable kit hidden away in the spec. But for the money, it’s hard to imagine a much better package than this.

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Every component maximises performance, and kit like the WTB Vigilante TCS Light/High Grip tyre on the front (where you need it) and faster-rolling Trail Boss on the back show that Calibre knows what’s up.

The frame is 1x-specific and uses a 12-speed SRAM Eagle drivetrain with an 11-50t cassette. Response under power is direct and efficient, thanks in part to the oversize crank axle running on one of SRAM’s latest DUB bottom brackets.

SRAM’s Guide RE brakes can kill speed quickly and are rock-solid reliable.

Mick Kirkman

For the £400 price hike over the standard 2020 Bossnut, you get a sorted and plush RockShox Sektor fork, a KS Rage-i post with a useful 125mm drop, and four-piston SRAM Guide RE brakes. These are ridiculously powerful because they’re designed to stop the heftiest e-MTBs.

The 780mm handlebar comes from trusted brand Spank, and Calibre’s own stem is nice and short at 45mm.

If I’m being really picky, I’d take the Schwalbe EVO tyre combo that Vitus offers, for its extra grip, over the Bossnut’s WTB rubber package.

Calibre Triple B ride impressions

The Triple B rides like bikes costing double the price, with its grip, rider position, frame stiffness and suspension action all being comparable to those of some £3,000-plus machines.

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Its cockpit puts you in the perfect position to rip it up, and its BB feels low, so you can swing through turns with the front tyre always in the sweet spot for steering and balance.

Not only is the suspension smooth and supple, but it’s also supportive and fluid, at both ends, with the Sektor fork reacting to repeated bumps and bigger hits better than any of the other three bikes on test: Norco Fluid FS 3, Marin Hawk Hill 1 and Vitus Mythique 29 VRS.

RockShox’ Sektor was the most responsive fork on test.

Mick Kirkman

While the chunky frame feels solid enough to chuck the bike about and smash through rough ground, it’s good to know that if you get carried away, the Guide RE brakes have your back, by being so powerful that they overcome the odd decision to spec a small 160mm rear rotor.

The Calibre’s affordable price is reflected in extra heft, so although your body weight is in the right place when sitting down and climbing, it can’t go uphill quite as speedily as pricier bikes – or even the slightly lighter Vitus, which also feels a tad smoother when pedalling or climbing.

Since the maximum grin-factor in mountain biking comes from the fast and flowy bits though, the Calibre rules, shining where you most need it to – the fun bits – in terms of handling, confidence and suspension.

The new bolt-thru rear axle increases stiffness and keeps the wheel locked in tightly.

Mick Kirkman

Calibre Triple B geometry

• Sizes (* tested): S, M, L*, XL
• Seat angle: 74 degrees
• Head angle: 65.5 degrees
• Chainstay: 43.6cm / 17.17in
• Seat tube: 48cm / 18.9in
• Top tube: 62.6cm / 24.65in
• Bottom bracket height: 32.8cm / 12.91in
• Wheelbase: 1,195mm / 47.05in
• Reach: 46cm / 18.11in