It’s the attitude of the Bossnut that really sets it apart

Product Overview

Overall rating:

Score 10

Calibre Bossnut EVO


  • Game-changing ride quality


  • The BB height could be lower


Calibre Bossnut EVO review


Price as reviewed:


Calibre does 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 Evo.

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

Winner of our entry-level suspension test three years in a row, makes the Calibre Bossnut the undisputed champ in the £1k category.

And like any prizefighter, it’s not just the vital stats that matter, even if they are important. It’s the attitude of the Bossnut that really sets it apart.

calibre bossnut evo

Calibre Bossnut EVO review

By placing ride quality above all else, Calibre has created a bike that isn’t limited by its price tag. And it’s largely thanks to one individual, Mike Sanderson, the man in the Bossnut’s corner with the vision to create an affordable bike that packs a mighty punch.

Last year the Bossnut saw a round of revisions that transformed it into the Evo version; making the switch to a 1x drivetrain was the big one. The 2×10 Shimano Deore setup replaced by SRAM’s NX 11-speed gearing, the 11-42t cassette and 32t chain ring providing a comprehensive gear range, and more importantly, the narrow wide chain ring ensuring that you ride isn’t constantly derailed by dropped chains.

Two less obvious updates were the move to wider rims, so you can run lower tyre pressures while maintaining tyre stability, and the frame also received stealth routing for a dropper seat post. Which is great, as the addition of dropper post is the only upgrade you’ll need to make to this bike.

This year it’s business as usual for the Bossnut Evo, so the bike you see here is identical to the one we tested last year. Well, if ain’t broke…

calibre bossnut evo

Well-tuned Monarch R shock rules on the trails


With RockShox suspension components front and rear the Bossnut is in very safe hands. Not only is the 130mm travel Recon suspension fork super sensitive and confidently composed, when it comes time to servicing it most bikes shops will happily break it down, safe in the knowledge that all of the spare parts are readily available. Day to day though all you’ll is a multi-tool to remove the front well, as the 15mm both-thru axle has no quick-release lever.

Calibre has also nailed the tune of the Monarch R rear shock. The rebound damping offering a very usable range of adjustment, even if slightly biased toward heavier riders running higher air pressures. And even if the frame doesn’t quite deliver on its promise of 130mm travel, we measured it closer to 120mm, it’s so effective as swallowing bumps that you never feel short-changed out on the trail.

calibre bossnut evo

WTB Vigilante tyre boosts grip at the front


The benefits of a good front tyre to increase confidence and control shouldn’t be underestimated, which is why the Bossnut gets a softer compound HighGrip WTB Vigilante up front. Confidence is boosted further by the wide 780mm Kore handlebars that, combined with the lock-on grips, extends to a whopping 800mm. Factor in the stubby 45mm stem and the cockpit on the Calibre wouldn’t look out of place on a race-ready enduro bike.

Having the confidence to go fast is only one side of the coin however, you also need control in equal measure. And with Shimano’s one-finger brakes offering superb modulation and ample power you’ll be able to stop on a dime.

calibre bossnut evo

11-speed SRAM NX rear mech and wide-range cassette


One year on and the Calibre Bossnut Evo feels every bit as impressive. Nothing about the specification is lacking and with the most effective suspension in test, the Bossnut finds traction where others falter, which simply encourages you to ride harder and have more fun. Which is what this bike is all about.

Granted, it’s the heaviest bike in test, but it’s also the most solid feeling, so the extra pounds are pure muscle. And given how hard you’ll ride this bike, that’s going to work in your favour longterm.

Could the Bossnut Evo be even better? Of course it could. The geometry could be a touch slacker and lower and the frame could have the square edges knocked off it to make it easier on the eye, the key corner being the somewhat redundant front derailleur mount. Would these updates transform the Bossnut? Hardly, but it could be enough for the tile holder to continue its uninterrupted winning steak.

calibre bossnut evo


With the best tyres, the best brakes, the best cockpit, and most importantly, the best suspension, the performance of Calibre Bossnut Evo easily transcends the limits of its price, to make it best entry-level suspension bike we have ever tested. Just don't forget to take advantage of the Go Outdoors discount card, which costs £5, and slices the price of the Bossnut Evo from £1,300 to £999. It’s an incredible saving on an incredible bike, but even at full price the Bossnut Evo would still be our first choice.


Frame:6061 T6 aluminium, 130mm travel
Shock:RockShox Monarch R
Fork:RockShox Recon RL, 130mm travel
Wheels:Formula hubs, WTB ST i29 rims, WTB Vigilante/Trail Boss 27.5 x 2.3/2.25in tyres
Drivetrain:Samox Trail DM 32t chainset, SRAM NX 1x11 r-mech and shifter
Brakes:Shimano MT500, 180/160mm
Components:Kore Durox 780mm bar, Calibre trail 45mm stem, Calibre trail seat post, WTB Volt Sport saddle
Sizes:15, 17.5, 19.5, 21.5in
Weight:15.16kg (33.42lb)
Size tested:19.5in
Head angle:67.1°
Seat angle:70.3°
BB height:339mm
Front centre:723mm
Down tube:677mm
Top tube:615mm