The Bossnut is back! Calibre’s bargain bouncer goes 29

After a total of five incarnations as a 27.5in bike, the new Calibre Bossnut rolls out on 29in wheels front and rear. And a bit more travel to boot.

2025 Calibre Bossnut in a nutshell

• 29in wheels front and rear (XS is 27.5 F+R)
• 135mm rear travel (up 5mm)
• 140mm fork travel (up 10mm)
• 64.5° head angle
• 78° effective seat angle
• Bottle bosses and 2 x accessory bolt pairings
• Dropper post as standard
• Shorter seat tubes
• Longer reach
• RockShox suspension
• Shimano Cues 10sp drivetrain and MT401 brakes
• Five sizes: XS, S, M, L, XL
• SRP £1,499 with GO Outdoors discount card

Let’s start with the end, as most of you will just want to know what it rides like. You’ll have to wait for a proper review until we get hold of final production bike but in the meantime I’ll fire out a few First Ride thoughts…

My overriding thought is that the new Bossnut is way better than any of the previous 27.5 Bossnuts.

Not (just) because it has grown-up size wheels at last, but more that it has geometry that doesn’t feel like it’s outdated (or about to be imminently outdated). The previous Bossnuts always seemed to get something of an easy ride in terms of reviews, almost purely due to the value proposition in my opinion. They were amazing VFM. But they never actually blew my mind when it came to the actual riding.

Having said that, I think the smaller sized Bossnuts were fine for their pilots. Us lanky riders weren’t so lucky. Too short (front rear and rear centre) and too slack in the seat angle department.

The new Calibre Bossnut is leaps and bounds better in terms of geometry. This XL size has a proper reach (500mm) but doesn’t have the skyscraper (530mm) seat tube of yore (it’s now a tidy 460mm). The head angle is more capable 64.5°. The steeper (78° claimed effective) seat angle and longer (445mm) chainstays make it immeasurably better not just as a climber but as an all-round mountain bike.

Another general improvement is in the controls and contact points. The shifter is lovely. The grips and saddle are nice. The dropper post… well, for a start there is one. And the L and XL droppers are 170mm, which is acceptable. The dropper remote is a proper job. The Shimano MT410 brakes are fine (if you don’t look at them – they ain’t pretty).

In terms of performance and capability, the new Bossnut impresses. We’ve been spoiled by high end brakes and tyres, so that took a bit of getting used to. But get used to it we did and the Bossnut got up, along and down everything we pointed it at.

The rear suspension felt a whole lot more active and usefully grippy than I remember the old Bossnut being. This is principally more due to RockShoc upping its entry level shock game than anything.

As mentioned, we’re due a proper production version of the 2025 Calibre Bossnut any day now. And we can’t wait to see what it can really handle. In the meantime, here’s some Press Release ‘n’ piccies stuff…

BOSSNUT 2025

The name Bossnut needs no introduction in the mountain bike world.

Since its launch in 2015 the Bossnut redefined what an entry level full-suspension bike was capable of.

It won countless awards and became the benchmark which other brands entry level full-sus bikes were measure against. If you wanted to get into mountain biking and didn’t have a huge budget then the Bossnut was the bike to buy.

The Bossnut quickly gained a reputation as the go-to bike for new riders or people getting back into the sport.

This sums up Calibre’s ethos of producing bikes that provide affordable performance.

The original bike went through 5 iterations and continued to grow in popularity until 2020 when due to covid our production ceased. It’s been over 4 years since the last model launched, 4 years of redevelopment, testing and refining to create what we believe to be the best entry level performance mountain bike on the market. The bike that your mate who is into Mtb will recommend to get you hooked and become one of us!

The original Bossnut built a cult-like following, what became clear to us was that people loved their Bossnuts in the same way that VW Transporter owners love their Bus. They want to upgrade them, personalise them and show them off.

This meant that the new bike needed to be built around a solid frame that would be worthy of the upgrades that people make and not just get them into mountain biking but join them on the journey and stand the test of time.

So what’s new?

The Bossnut has always been a short travel trail bike that is designed to be fun to ride above anything else. The updated geometry makes the bike more capable than ever but it also keeps it’s playful poppy feel.

The biggest change to the bike is that it is now rolling on 29” wheels. We tested 27.5”, 29“ and mullet versions of this bike and the 29er came out on top making the bike feel confident, fun and fast rolling.

The travel has also been increased from 130mm all round to 140mm on the front and 135mm on the rear making the bike an even more capable all-rounder that can take the bigger hits as your riding progresses.

We have seen how hard the previous generation bikes got pushed, from UK enduro racing to alpine seasons so we have made sure that the new bike is built to last. We developed a chunky custom tubeset and redesigned the forgings to strengthen every part of the frame. We have had our riders absolutely hammering them and nobody has managed to break one of the new frames. We have also taken care of the details, we’ve got space for a bottle cage inside the frame, improved cable management and added bosses for tool storage under the toptube. We’ve also gone for Boost spacing on the hubs adding stiffness and keeping the frame futureproof.

One thing that the original Bossnut didn’t have was a dropper. It’s now hard to imagine riding a trail bike without one so we have spec’d the bike with a size specific dropper with a solid alu lever out of the box.

Geometry and sizing

Bossnut customers span a massive age and size range and it is important to us that it is accessible to everyone. The new bike now comes in 5 sizes. The Small to XL sizes come with 29” wheels and the XS bike for teenagers and smaller riders comes with 27.5” wheels.

We’ve got a slack 64.5 degree head angle for stable descending, a steep 78 degree seat angle giving a composed climbing position, a low BB for a planted feel in the corners and a low standover for manoeuvrability. A shorter seat tube length across all the sizes gives riders the option of sizing up if they prefer a more stable bike with a longer reach and sizing down if they prefer a shorter more nimble bike. We have 170mm droppers on the L & XL sizes, a 150mm on the M bike and 125mm on the S & XS bikes.

Components

We think that your first mountain bike can get you hooked on riding. Creating a bike that makes riding fun and accessible has always been the priority with the Bossnut. Finding the right balance of components that will keep the bike at a price point but perform at a level that makes no excuses or compromises when on the trail.

As always the suspension is taken care of by Rockshox, a 140mm Rockshox Recon RL fork up front and a Rockshox Deluxe Select shock on the rear. They are simple to set up and work together with the linkage to give an active and composed ride feel.

The brakes are Shimano MT401 with 180mm rotors front and rear. These give excellent stopping power and a comfortable and consistent lever feel. The drivetrain is also taken care of by Shimano. The brilliant new Cues 10 speed set up offers a wide range 11-48 cassette is built for longevity and shifting under load. We’ve gone for Maxxis tyres with a grippy Minion DHF up front and a fast rolling Forkaster on the rear. These are seated on 30mm internal tubeless ready rims.

Things that matter

The Bossnut is and always has been a bike that strives to give the rider the best experience possible.

The bike is designed around the things that make genuine performance differences when you are on the trail. The past four years has been an amazing journey, designing and refining the frame and testing lots of components. The result is what we think gives the right balance of what matters on a mountain bike. All the bits that make a difference to the performance and none of the bits that don’t. We have created what we believe is the bike that will give you the best experience of mountain biking at an accessible price point.

Calibre Bossnut specification

• Frame // 6061 alloy, 135mm travel
• Shock // RockShox Deluxe Select R, 210×55
• Fork // RockShox Recon Silver RL, 140mm
• Wheels // 30mm ID Tubeless Ready rims on Shimano TC500 hubs
• Front Tyre // Maxxis Minion DHF EXO, 29 x 2.5in
• Rear Tyre // Maxxis Forekaster EXO 29 x 2.4in
• Chainset // Shimano Cues, 170mm, 32T
• Drivetrain // Shimano Cues 10sp, 11-48T
• Brakes // Shimano MT410, 180/180mm
• Stem // 45mm, 31.8mm
• Handlebars // 780 x 20mm, 31.8mm
• Grips // Calibre Ribbed Lock-on
• Seat Post // X-Fusion Manic, 170mm
• Saddle // Calibre Trail
• Weight // TBC

Geometry of our XL size

• Head angle // 64.5°
• Effective seat angle // 78°
• Seat tube length // 460mm
• Head tube length // 125mm
• Chainstay // 445mm
• Wheelbase // 1,277mm
• Effective top tube // 636mm
• BB height // 38mm BB drop
• Reach // 500mm

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