Bikes up to 60% offWe monitor over 40,000 bikes daily to find the best prices

Today’s Deals

2023 Calibre

BOSSNUT

A 27.5″ aluminum frame full suspension trail bike with upper mid-range components.

Weight33.5 lbs  
FrameAluminum
SuspensionFull, 130 / 130mm
ForkRockShox Recon Silver RL
ShockRockShox Monarch R
Wheels27.5″ Aluminum
Drivetrain1 × 12
GroupsetSX Eagle
BrakesSRAM Level T Hydraulic Disc
Learn about Calibre
Where to Buy
Similar Bikes
Top Comparison
Insights
Ride Feel

Based on frame geometry and build specs.

Terrain
easyextreme
Handling
nimblestable
BOSSNUT
Other Trail bikes
Gearing

A bike with lower gearing will be easier to ride up steep hills, while a higher top end means it will pedal faster down hills.

Lowest gear

(climbing)

24 mph

BOSSNUT

26 mph

Similar Bikes

Highest gear

(descending)

Sizing
SM

5'2" – 5'8"

MD

5'6" – 5'11"

LG

5'10" – 6'3"

XL

6'1" – 6'7"

🐐 Estimated

Rider Fit Notes

None yet.

Do you have this bike? Help other riders make a decision about which size will work for them by sharing your own size and fit notes.

Reviews

Summary

The Calibre Bossnut is a trail bike that consistently impresses with its aggressive geometry, outstanding value for money, and durable build kit. It excels in downhill stability and climbing efficiency, thanks to its slack head angle and steep seat tube angle, though some riders may find the rear suspension slightly overdamped. The bike's performance and components rival those of more expensive models, making it a standout choice in its price range.

Pros
  • Excellent aggressive geometry

  • Outstanding value for money

  • Durable build kit

  • Slack head angle and steep seat tube angle for stability and climbing efficiency

  • RockShox suspension components

Cons
  • Rear shock is over-damped for general riding

  • No chainstay protection

  • Heavy weight

  • Lacks subtlety over irregular surfaces

  • Brakes lack sensitivity and power in wet conditions

Key Quotes
Calibre’s new Bossnut is an outstanding mix of sorted handling and geometry in a seriously tough frame that’s begging you to ride it flat out straight away.
Bike Perfect logoBike Perfect
It’s no surprise the Bossnut is so popular because it provides the best all-round trail performance of any bike at this price.
BikeRadar logoBikeRadar
the new Bossnut looks a lot more like something, say, Cannondale would produce
MBR logoMBR
The original Calibre Bossnut could. Launched in 2015 in the UK, it reset expectations of what a budget bike could do.
Pinkbike
I’m going to basically go on about how good this bike is.
Singletrack World logoSingletrack World

Feedback?

View all reviews

Bike Perfect
The all-new Calibre Bossnut is a fantastic comeback and only a shock tweak away from being a totally awesome budget full-sus MTB

Oct 2024

The affordable mountain bike market has never had more excellent, new, or 'old stock sold cheap’ options than it does now. So is the all-new Calibre Bossnut a straight to the top comeback? Guy Kesteven has been putting the hours in to tell you exactly what you need to know about this awesome affordable all-rounder

Highs
  • Excellent aggressive geometry

  • Outstanding RockShox and Shimano spec for the money

  • Proven dropper post as standard

  • Quality contacts points

  • Full XS to XL size range

Lows
  • Rear shock is over-damped for general riding

  • No UDH dropout or chainstay protector

Read Review

MBR
All of this for just £1,500? Calibre's Bossnut is back, with more travel, bigger wheels and a higher quality frame - MBR

Oct 2024 · Alan Muldoon

After a four year hiatus the Calibre Bossnut is back. It’s got bigger 29in wheels, more travel and now comes with a dropper seat post fitted as standard. Yup, the price has crept up to £1,500, but as I found out, it’s still worth every penny. 2025 Calibre Bossnut need to know: Sleek alloy frame with modern geometry and 135mm travel Fork travel is now 140mm Five frame size: XS is 27in, S to XL 29in 29in bikes, also MX compatible with aftermarket MX link Two tool mounts under top tube External cable routing for rear brake and drivetrain Boost bolt-thru axles front and rear Spare parts, made in Sheffield Frame and geometry One look at the new Bossnut frame and it’s crystal clear that Calibre had upped its game. Now, I’m not implying that the old bike wasn’t cool, it’s just that the new Bossnut looks a lot more like something, say, Cannondale would produce, and not what you’d expect from what’s essentially an outdoor equipment supplier. That new aesthetic is a direct result of Calibre switching production facilities, and having a desire to move the needle once again in the entry-level full suspension category. And move the needle it has. Which is impressive given how many generations of Calibre Bossnut we’ve tested and highly rated since it came out in 2015. Let’s take a quick look at the geometry and sizing for example. Yes, it’s longer, lower and slacker than before, but more importantly it’s vital stats are right up there with cutting-edge trail bikes like the Canyon Spectral and Specialized Stumpjumper 15. Albeit a 16.84kg version. There’s simply no avoiding the weight penalty on more affordable bikes, especially if they are built to be ridden hard. And in this instance, entry-level doesn’t mean dumbed down. The Bossnut gets a 64.4º head angle for improved steering stability. A steep 77.1º seat tube angle to put you in a better position for climbing and a longer reach and short stem to improve the overall fit. In fact, it’s got all the numbers you are looking for in a modern trail bike. It’s also got external cable routing, so swapping out parts and upgrading is super easy for the home mechanic. Granted it’s not as clean or as sleek as having internal cable routing, but the second major plus point is there’s zero cable rattle. And because the Bossnut is designed as a trail bike, Calibre has made the switch to full 29in wheels, even though every previous generation Bossnut rolled on 27.5in wheels. It hasn’t forgotten its roots, however, or shorter riders, so the XS size rolls on smaller 27.5in wheels for a better overall fit. Calibre also appreciates that some riders may need more tyre clearance, so it’s also producing a longer MX shock extender, right on its doorstep in Sheffield, for correcting the geometry when converting to an MX setup. MX links will be sold separately. So, to recap. Calibre offers the Bossnut in five frame sizes, …Continue reading »

Highs
  • • Great ride quality for the price

  • • Dialled geometry and sizing

  • • RockShox suspension components

  • • Durable build kit

  • • MX conversion for shorter riders

Lows
  • • No chainstay protection

  • • Slightly overdamped suspension

  • • Spokes in rear wheel lost tension

  • • Aggressive riders will want a better rear tyre

  • • Needs a higher rise bar

Read Review

Pinkbike
First Look: 2025 Calibre Bossnut - The Budget Boss Is Back

Oct 2024 · Seb Stott

Though designed as a trail bike, Calibre say it's built to last, with redesigned tubes intended to strengthen every part of the frame.

Read Review

BikeRadar
2020 Calibre Bossnut review

Jan 2020 · Tom Marvin

Impeccable trail performance for the money and an excellent-value spec too

Highs
  • Good shape

  • Great kit for the money

  • Amazing trail manners

Lows
  • Non-Boost axles limit your wheel upgrade options

  • SRAM Level T brakes lack power with stock 160/180mm rotors

Read Review

Singletrack World
2020 Calibre Bossnut First Ride Impressions - Super affordable fun!

Aug 2019 · Andi Sykes

First ride impressions of the 2020 Calibre Bossnut, a bike that proves that you don't need to spend a fortune to have fun on 2 wheels.

Read Review

Geometry
Specs
Build
Frame

6061 Hydroformed alloy frame, tapered headtube, forged rocker link, 130mm travel, 12 x 142mm bolt through rear end

Fork

Rockshox Recon RL Solo Air 130mm, alloy tapered steerer, 15 x 100mm Maxle, gloss black with fast black stanchions

Travel130mm

Spring TypeAir

Shock

Rockshox Monarch R, custom tune, 130mm travel, 190 x 51 eye to eye, gloss black.

Travel130mm

Headset

FSA No. 57E Orbit tapered

Stem

Calibre 45mm length, 31,8mm bar

Handlebar

Calibre Alloy, 780mm length, 30mm rise, 31.8mm OD

Saddle

Calibre Trail

Seatpost

Calibre Alloy, 30.9 x 350mm

TypeRigid

Pedals

Plastic platform test pedals

Groupset
Rear Derailleur

SRAM SX Eagle

Crank

SRAM SX Eagle Powerspline, 170, 32T

Shifters

SRAM SX Eagle

Cassette

SRAM 12 Speed, 11 - 50T

Brakes

SRAM Level T

TypeSRAM Level T Hydraulic Disc

Wheels
Rims

WTB ST i29 TCS 2.0

Front Hub

Formula 32H, 6 bolt

Rear Hub

Formula 32h, 6 bolt

Tires

WTB Vigilante High-Grip Comp, 27.5 x 2.3 front. WTB Trail Boss comp, 27.5 x 2.25 rear

Rider Notes
Riders Also Viewed

First added May 11

Last updated July 13

Not listed for 685 days