Calibre Bossnut Evo review

Absolutely kills it if £1,000 is your limit

Our rating 
4.5 out of 5 star rating 4.5
GBP £999.00 RRP | AUD $1,819.00 | USD $1,309.00

Our review

Sorted frame and outstanding parts for the cash mean the Bossnut is unbeatable for under £1k
Buy if, You want the best full-sus for under £1,000
Pros: Really well-chosen, amazing value, trail-ready componentry; sorted, reliable RockShox suspension with thru-axle fork accuracy; well-balanced, easy to ride all-rounder geometry
Cons: Needs a dropper post and better tyres when you can afford to upgrade
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Calibre blew the £1,000 bike scene apart with the original Bossnut and then the V2. It’s taken all the feedback and used it to create a hat trick of three-figure full-sus domination, with the Calibre Bossnut Evo.


The Evo frame is largely unchanged from the V2, apart from the addition of external and internal dropper post cable routing. That means you still get a (redundant) front mech mount, 135mm QR rear axle and imperial-size RockShox Monarch shock.

While no dropper is included, you at least get a QR seat collar for rapid manual adjustment. A tapered head tube and short one-piece forged rocker link keep tracking obedient despite the relatively narrow main pivot.

The rear pivot is on the seatstays, not the chainstays, so the wheel moves in a simple arc, but the rocker slightly modifies the shock rate.

The 67-degree head angle, 780mm bar and 45mm stem increase control and confidence without being a handful on flatter/climbing trails
Andy Lloyd / Immediate Media

Calibre has put together an outstanding package for £999 (with discount card). While the Recon fork isn’t the latest Boost-width (110mm) version, its 15mm thru-axle adds welcome steering accuracy and security compared to a QR.

The WTB rims are wide for extra tyre support and easy to turn tubeless, and the tyres are acceptable for the price. Shimano’s Deore brakes offer better modulation and power than their M300-series anchors, and SRAM’s clunky NX 11-speed shifter and rear mech are relentlessly reliable.

The Kore bar and own-brand stem match the handling well. You even get lock-on grips.

Calibre Bossnut Evo ride impressions

Your initial contact with a bike is always important, and the Evo’s 780mm bar and 67-degree head angle give a reassuringly safe feel, without being super-wide or slack.

The 45mm stem ties everything together nicely, so the steering is light and obedient but the bike doesn’t need to be pointed downhill and moving fast for it to make sense.

With a relatively short 445mm reach and 1,145mm wheelbase (large), it doesn’t feel as unshakably stable through rocks and roots or scythe through high-load turns like longer bikes.

There’s routing for an internal or external dropper seatpost cable/hose, but you’ll have to add the actual post yourself
Andy Lloyd / Immediate Media

It’s quicker and easier to change direction in tighter situations, though, encouraging you to play with trail features rather than plough through them.

The 67-degree head angle means the fork doesn’t flop around like a sulky teenager on steep climbs. In short, the geometry works just fine for what most people spending £1,000 are going to think of as mountain biking.

The Calibre’s back end isn’t as rock-meltingly smooth as some of its competitors, but it does a good job of minimising impact force while keeping the bike level and the rear wheel connected.

The simple Monarch R shock has better peak oil flow than more complex compression-adjustable dampers, so the 130mm of rear travel will swallow surprisingly large blocks and drops before things get sketchy.

Although there’s no lockout lever for climbs and road sections, the Evo pedals well enough that this isn’t an issue. The Recon fork retains control a long way down rocky descents before your forearms start to blow up, and is easy to adjust for rider weight, too.

While Calibre has done a truly outstanding job with the design and equipping of the Bossnut Evo, it unsurprisingly hits its limits slightly earlier than the 40 to 50 percent more expensive bikes it is often compared to.

The cheap WTB tyres on wide rims perform as well, if not better, than most you’ll get on a bike at this price, but they slip sooner than top-spec rubber and lack stability at lower pressures.

Other bikes at this price do offer more tautness to their frames and the Bossnut’s suspension isn’t as capable as some contenders.


If you’re after a really easy to ride, remarkably controlled and permanently enthusiastic and playful trail all-rounder at a ridiculous-value-for-money price, though, nothing else I’ve ridden comes close for under £1,000 — and it’s available for international delivery too.

Product Specifications


Name Bossnut Evo
Brand Calibre

Available Sizes S M L XL
Rear Tyre WTB Trail Boss 27.5x2.25in
Wheelbase (in) 45.08
Top Tube (in) 24.41
Seat Tube (in) 19.29
Chainstays (in) 17.13
Bottom Bracket Height (in) 13.39
Spoke Type 32x stainless
Weight (kg) 14.89
Stem Calibre Trail, 45mm
Shifters SRAM NX (1x11)
Seatpost Calibre Trail rigid
Seat Angle 73.5
Saddle WTB Volt Sport
Rims WTB TCS i29
Rear Wheel Weight 3030
Rear Shock RockShox Monarch R
Bottom Bracket external
Front Hub Formula
Brakes Shimano Deore MT500, 180/160mm rotors
Cassette SRAM PG-1130, 11-42t
Chain KMC X11
Cranks Samox, 32t
Fork RockShox Recon RL Silver, 130mm (5.1in) travel
Frame Material Hydroformed and custom-butted 6061-T6 aluminium
Front Tyre WTB Vigilante 27.5x2.3in
Rear Hub Shimano
Front Wheel Weight 2280
Grips/Tape Calibre single lock-on
Handlebar Kore Durox, 780mm
Head Angle 67
Headset Type FSA No.57
Rear Derailleur SRAM NX
Frame size tested L