The Bossnut has had a full re-design. It’s got new geometry, new hydroformed tubes and it’s had a serious spec upgrade.

Described by the press as “A hugely important mountain bike” the original Bossnut changed the game and made it possible for anyone to own a properly capable mountain bike for a grand.

The Bossnut is a gateway to proper full suspension riding for many people. Since it’s launch we have been overwhelmed with the positive response to the bike and most importantly from people who are either new to mountain biking or have been able to get back into the sport and not be held back by their bike.  The new model builds on everything we have learned at Calibre and is by far our best Bossnut yet.


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Frame6061 Hydroformed alloy frame, tapered headtube, forged rocker link, 130mm travel, 12 x 142mm bolt through rear end
ForkRockshox Recon RL Solo Air 130mm, alloy tapered steerer, 15 x 100mm Maxle, gloss black with fast black stanchions
Rear shockRockshox Monarch R, custom tune, 130mm travel, 190 x 51 eye to eye, gloss black.
DrivetrainSRAM SX Eagle 12 Speed
ShiftersSRAM SX Eagle
Rear DerailleurSRAM SX Eagle
ChainsetSRAM SX Eagle Powerspline, 170, 32T
CassetteSRAM 12 Speed, 11 - 50T
BrakesSRAM Level T
DiscsSRAM Centreline 180mm Front, 160mm Rear, 6 bolt
RimsWTB ST i29 TCS 2.0
TyresWTB Vigilante High-Grip Comp, 27.5 x 2.3 front. WTB Trail Boss comp, 27.5 x 2.25 rear
Front HubFormula 32H, 6 bolt
Rear HubFormula 32h, 6 bolt
StemCalibre 45mm length, 31,8mm bar
BarsCalibre Alloy, 780mm length, 30mm rise, 31.8mm OD
HeadsetFSA No. 57E Orbit tapered
Headset upper bearingFSA bearing 36 x 45, 1 1/8” – Code TH-873E (I.D-30.2mm, O.D-41mm, Height-8mm)
Headset lower bearingFSA bearing 36 x 45, 1.5 – Code TH073 (I.D-40mm, O.D-51.8mm, Height-8mm)
SaddleCalibre Trail
SeatpostCalibre Alloy, 30.9 x 350mm
PedalsPlastic platform test pedals
Weight15.2kg (Size L, no pedals)
Bike diagram


STL (Seat tube length)375mm430mm480mm530mm
ETT (Effective top tube)585mm605mm626mm645mm
RE (Reach)423.5mm442mm460mm476mm
HA (Head angle)66666666
HT (Head tube length)112mm117mm127mm137mm
SA (Seat tube angle)74.574.574.574.5
RC (Rear centre)436mm436mm436mm436mm
BBD (Bottom bracket drop)24mm24mm24mm24mm


5'2" - 5'6"157 - 168SMALL
5'5" - 5'10"165 - 178MEDIUM
5'10" - 6'1"177 - 185LARGE
6' - 6'6"183 -198XL