Trail and Enduro Bikes

Calibre Bossnut

The lowest priced bike in this year’s Dirt 100, the Calibre Bossnut is unbelievable value. A trail bike that offers an inspired ride along with up-to-date sizing and a very complete specification. Everything has been considered.

Calibre is a brand exclusive to Go Outdoors and has been designed and developed by their team here in the UK. With trail bike geometry often being compromised, especially on sub £2K machines, it’s clear that Calibre’s design team have ridden plenty of cutting edge designs and know what works. The Bossnut’s frame layout and detailing mirrors bikes at more than twice the price and this becomes immediately apparent within the first few minutes of the ride. This ‘entry level’ bike is an absolute blast to ride…

If you’re not going for the larger 29” wheels on your trail bike it seems that the recipe of 130mm of travel and 27.5”/650B wheels can make a very sweet combination. The Bossnut’s aluminium frame has been designed around a slack 67° head angle, and has a reasonably lengthy reach, placing you in a balanced position on the bike. The wheelbase and bottom bracket heights are bang on and work well with the large volume WTB tyres that are standard spec.

With quality air-sprung suspension front and rear (RockShox Sektor fork and Monarch R shock) it’s easy to tune to get the settings right for you – plus there are rebound adjustment dials on both units and a lockout on the fork. This is an area that is often compromised on sub £1500 bikes, with cheap rear shocks and steel-legged coil sprung forks giving compromised control.

With sorted geometry, excellent suspension and three realistic sizes, Calibre have done a great job with the frame. So, what about the Bossnut’s spec?

It’s Shimano throughout with the gearing with a full 2×10 speed Deore set-up, with a ‘Shadow Plus’ clutch rear mech. While bikes such as the Marin Hawk Hill have gone for a single ring transmission, Calibre have stuck with a double chainset and this is arguably a choice which buyers at this price would be looking for. Brakes are Shimano Deore (also a pick in the 2017 Dirt 100) and it’s good to see a 180mm rotor up front – you’ll need it on this bike.

Wheels, just like forks and shocks, are often compromised at this price point but again it is hard to argue with what is standard spec here. Shimano Deore hubs are a solid choice and are laced to WTB tubeless ready rims. WTB also supply the rubber, with a chunky 2.3” Vigilante up front and a faster rolling Beeline out the back.

Ritchey supply the cockpit, with a 760mm wide Trail bar and a 70-80mm 4Axis stem. We’d switch to a shorter stem (if the reach allows) and maybe a wider bar too. It’s one the few areas we’d upgrade.

The original Bossnut is only available in this spec but there is now a recently launched women’s version with a lighter shock tune, narrower handlebar, slimmer grips and an appropriate saddle. With a list price of £1300 you can sign up for a Go Outdoors’ discount card allowing you to buy this bike for just under a thousand pounds.

This bike can dish out a ride that compares to trail bikes with much higher prices. It is well equipped, with excellent components and at sells at a truly affordable price. Just add a dropper post and a shorter stem and let it rip…

UPDATE: This Bossnut is now joined by the Bossnut V2 with tweaks to the frame and rocker. Also, for 2017/18 Calibre introduce the Beastnut with the same frame as the V2 but with a 140mm fork, SRAM Guide RE brakes, a 1×11 drivetrain and a dropper post.

Calibre Bossnut


Selected for Dirt 100 2017

View the full 100
Newsletter Terms & Conditions

Please enter your email so we can keep you updated with news, features and the latest offers. If you are not interested you can unsubscribe at any time. We will never sell your data and you'll only get messages from us and our partners whose products and services we think you'll enjoy.

Read our full Privacy Policy as well as Terms & Conditions.