Price has crept up but the jump in performance makes it well worth the extra money

Product Overview

Overall rating:

Score 10

Calibre Bossnut


  • New sleeker frame profile reflects the improved ride quality.


  • It’s no longer the best bike for under £1k.


Calibre Bossnut review


Price as reviewed:


MBR Editor’s Choice 2019: Calibre Bossnut, £1,099

At risk of sounding like a broken record, or for our younger readers, producing content that looks like it’s been created with Boomarang, the Calibre Bossnut returns to Editor’s Choice for the second year running.

No mean feat, given that brands like Jamis, Boardman and Giant were all keen to take the mighty Bossnut down in this year’s entry-level full suspension bike test – a test that the Bossnnt has won three years on the trot.

What makes the Bossnut so much better than any other bike in its class? It would be easy to assume that it’s some magic combination of geometry and suspension that gives it an edge, offering a ride quality that is greater than the sum of its parts. But that’s simply not the case. Because even though the geometry and sizing on the Bossnut are good, both have been improved for 2020, which we’ll get to in a minute.

So it’s the parts themselves, or more specifically how Calibre has sweated every single component on the Bossnut to offer the highest level of performance at the given price point. As such, the Bossnut isn’t hamstrung by bad tyres, a dodgy shock tune or fork that isn’t effective at ironing out the bumps. In that respect Calibre has stuck the perfect balance between performance and price, so you don’t have to compromise on ride quality. Nothing holds the Bossnut back, and the only limits here are your fitness, skill level and imagination.

What’s changed for 2020?

What hasn’t changed? Well the rear tyre, grips and seat post are the same as last year but that’s about it. The most obvious update for 2020 is the frame. Gone are the boxy tubes, replaced instead with sleek hydroformed designs that usher in modern sizing and geometry, not simply a new aesthetic. The specification has moved on too, a 12-speed Eagle drivetrain letting you climb higher and ride further than ever before. Yes, the price has crept up by £100, but with the addition of a bolt-thru rear and all of the other updates to the build kit, the Bossnut is still very much the entry-level bike to beat.

calibre bossnut

New £1,100 Calibre Bossnut: first ride review

Calibre Bikes do it again. If you want a full-suspension bike that’s a total blast without blowing your budget, you have to get the Calibre Bossnut.

>>> Best mountain bike 2019: all you need to know

Calibre Bossnut need to know

  • Hydroformed tubing profiles and revised geometry give the latest Bossnut a sleek, modern profile
  • Swapping to a 142x12mm bolt-thru rear end improves frame stiffness and wheel security
  • SRAM SX Eagle drivetrain with its 11-50t cassette expands the range of the Bossnut
  • Rail corners even harder with the High-Grip compound WTB Vigilante tyre up front
calibre bossnut

Swooping lines and a slacker head angle are welcome frame changes

Game changing is a term that’s overused, especially when it’s used to describe products or ideas that are simply updated versions of what came before… hardly game changing at all then.

Take the latest version of the Calibre Bossnut for example. It’s seen a raft of revisions to the geometry, tubing profiles and specification, all of which we’ll dig deeper into in a moment, but it’s hardly a game-changing bike.

calibre bossnut

A single chainring cuts weight and boosts reliability

That honour goes to the original Bossnut. Before Calibre unleashed the first Bossnut on the unsuspecting public and media, the £1k full-suspension category was awash with heavy XC bikes with poor handing, crappy suspension and lethal tyres.

We’d been saying for years that good geometry costs nothing, and all that was required was for someone to care enough about these entry-level bikes to apply it. Mike Sanderson, the designer behind the Bossnut, changed the game by doing just that.

calibre bossnut

Lighter shock tune makes for a sprightly ride

Once the shape of the attitude of the bike were set, the next hurdle to overcome was finding parts that wouldn’t hold the bike back. No mean feat with a price capped at £999. But Calibre delivered and the rest is history, the Bossnut dominating the £1k class like nothing that came before it.

Expectations change though, and as good as the original bike was it’s human nature to want more and Calibre delivered. The V2 was better still then came the Evo. The most recent round of versions sees Calibre drop the Evo tag, but it’s certainly moved the game on again.

calibre bossnut

SRAM brakes replace Shimano but there’s no less of performance

Changes to the geometry roll in a slacker 65.4 degree head angle for improved confidence at speed and a steeper 74.5 degree seat angle to get your weight more forward on the climbs.

The bike still has 130mm travel, but the shock tune has been lightened up a hair to give the ride more pop. Something that was made possible by the revised pivot layout and the switch to a single chain ring drivetrain, the gear range now expanded to include a 50t bail out gear on the SRAM SX Eagle cassette.

calibre bossnut

High-Grip Vigilante front tyre uses softer compound rubber

Visually the bike has evolved too. Gone are the boxy tubes, replaced instead by soft edges similar in style to the hydroformed tubes on the Calibre Sentry. The frame also get a bolt-thru dropouts to shore up the rear end, no bad thing given how hard you can ride this bike.

Buy Now: Calibre Bossnut Evo from Go Outdoors for £899

calibre bossnut

How did it ride?

Probably the most surprising thing about the Bossnut is just how similar the riding position is to the Specialized Stumpjumper and Trek Fuel EX that I tested recently. Sure the Bossnut is over a kilogram heavier and has smaller 27.5in wheels, but the updated sizing and geometry mean that instantly feels like a thoroughly modern trail bike.

The High-Grip compound WTB front tyre gives you the confidence to really lean the bike into turns or stay high on wet, off camber roots, while the more lively response from the lighter shock tune makes the bike ride lighter than the scales suggest.

Yes, the price of the Bossnut has crept up by £100 but the jump in performance makes it well worth the extra money.

calibre bossnut


Frame:6061 T6 aluminium, 130mm travel
Shock:RockShox Monarch R
Fork:RockShox Recon RL, 130mm travel
Wheels:Formula 32h hubs, WTB ST i29 rims, WTB Vigilante/Trail Boss 27.5 x 2.3/2.25in tyres
Drivetrain:SRAM SX chainset 32t, SX Eagle r-mech and shifter
Brakes:SRAM Level T, 180/160mm
Components:Calibre alloy 780mm bar, Calibre 45mm stem, Calibre 30.9mm alloy post, Calibre Trail saddle
Sizes:S, M, L XL
Weight:15.43kg (34.02lb)
Size tested:L
Head angle:65.4°
Seat angle:71.5°
BB height:327mm
Front centre:758mm
Down tube:700mm
Top tube:624mm