Nukeproof Reactor 290 ST Factory Carbon Bike

Crosscountry/backcountry/upcountry/downcountry: However you define it, the new Reactor ST does it all and everything in between! It just might be the most versatile bike we have ever made.

Introducing the all new Nukeproof Reactor 290 ST; a limited edition lightweight, short travel version of the Reactor that is designed to tackle serious miles efficiently and comfortably, for all day fun in the saddle.

With a 130mm fork combined with 125mm of rear suspension, the Reactor ST combines the best of an enduro bike (long, low and slack) with the best of an XC Race bike (lightweight spec and efficient suspension) to create a sprightly yet seriously capable machine.

Frame Construction:

To optimise the weight, strength and stiffness, the Reactor 290 ST Carbon frame features a full UD woven carbon fibre frame set (Including chain and seat stays).

Adjustable Geometry:

The Reactor ST features a 66.8° (66.3° Low) Headangle atop a 76.3° (75.8° Low) seat angle across a 460mm reach on a Medium frame. We also offer the frame in Large and X-Large sizes. The Reactor ST frames feature the same “flip chip” design as the regular Reactor frame to adjust the geometry from “Trail” to “Rail mode”.

Trail – As the name suggests, this setting is best suited for trail riding. It is for riders who get as much enjoyment from the climb as the descents.

Rail – The Rail setting turns the Reactor ST into a more aggressive machine, dropping the bottom bracket 6mm and slackening the head angle by half a degree. It is there to maximise the descending capabilities.

Suspension Design:

To ensure the bike could climb as well as it descends, we designed the 4 bar Horst linkage to have higher levels of anti-squat for climbing gears but lower levels when you drop down the cassette. This means that the bike can behave itself on the climbs but when you get it up to speed, it turns into a trail hooligan. The combination of low anti-squat and progressive rate give ultimate small bump compliance (removes rough trail and root chatter) with good mid stroke support for cornering/pumping and end stroke progression for aggressive riding. Balanced anti-rise figures allow the Reactor ST some squat when braking hard, maintaining rider position and providing a good amount of pressure through the tyre to ensure traction. The Reactor ST is designed to reward the rider and ensure you get that stoke factor in on any ride.



Reactor 290 Carbon
Material: Ultra Strong T700/800 Monocoque Carbon Fibre
Fork Travel: 130mm
Axle to Crown: 537mm
Fork Offset: 51mm
Shock Travel: 125mm
Wheels Size: 29″
Max Tyre Size: 2.6″
Shock Size: 210×47.5mm
Shock Hardware F: 25x8mm
Shock Hardware R: 30x8mm
Sizing: M/L/XL
Headtube: 44-56mm Tapered Semi-Integrated
Headset: ZS44-28.6 – T2 / ZS56/40 – B8
Bearings Required: 2x NP-5 (6902 2RS), 4x NP-7 (6800 2RS), 4x NP-106 (6901 2RS)
Seatpost: 31.6mm (Internal Routing for Dropper Seatpost)
Seat Clamp: 36.4mm
BB: Threaded 73mm BSA
Rear Hub: Boost 148x12mm
Rear Axle: Sram Maxle Stealth M12x1.75 180mm
Chain Guide: ISCG05
Brake Mount: 180mm Direct Post
Protection: 3D Contoured Rubber Frame Protection for DT/SS/CS





FrameNukeproof Reactor 290 Carbon, 125mm Travel, UD woven Carbon Fibre front triangle/chain stays/seat stays, internal cable routing, custom tuned rear shock, Enduro bearings, threaded bottom bracket, boost 148mm rear axle spacing, 3D contoured frame protection
ForkFox 34 Float, Factory Series, Kashima, Fit 4 Damper, 130mm, 51mm Offset, BOOST, Black
ShockFox Float DPS, Factory Series, Kashima, 3 Position, EVOL, Custom LCL, LRL, CMF tune, 5mm, Bearing End (0.2 Spacer fitted.)
Front Wheel DT Swiss XM1501 SPLINE 25,29", Centrelock, 110x15mm
Rear Wheel DT Swiss XM1501 SPLINE 25, 29", Centrelock, Shimano Microspline Driver, 148x12mm
TyresMaxxis Rekon Race 29”x2.35 EXO/TR,
Crankset Shimano XT M8100 12-Speed, Hollowtech 2, 170mm, 30T, 52mm Chainline
Shifter Shimano XT M8100-R, 12-speed Rapidfire Plus, I-Spec EV
Rear DeraileurShimano XT M8100, SGS 12-Speed, Shadow Plus
CassetteShimano XT M8100-12, 12-Speed (HYPERGLIDE+), 10-51T
BrakesShimano XT M8100, 2 Pot Brake, Metallic Pads
RotorsShimano MT800, 180mm
HandlebarsNukeproof Horizon Carbon 25mm Rise, Width - M780mm, L800mm, XL800mm)
StemNukeproof Horizon, 50mm, Black
Grips Nukeproof Sam Hill Signature
SaddleNukeproof Horizon SL, Orange
SeatpostRockShox Reverb Stealth with 1x Remote, 31.6mm; S: 346mm length, 125mm drop; M: 409mm length, 150mm drop; L: 462mm length, 175mm drop; XL: 514.5mm length, 200mm drop
HeadsetNukeproof, 44-56 IITS
Weight 28lbs


Ultra Strong T700/800 Monocoque Carbon Fibre
Weiht: 28lbs
Trail/ Rail flip chip
Threaded 73mm BSA
Boost 148mm Rear axle spacing


KEY Small Medium Large Extra Large
Seat TubeNA 420/16.5"460/18"510/20"
Effective Top TubeNA608638673
Head AngleNA66.8 (Rail 66.3) 66.8 (Rail 66.3) 66.8 (Rail 66.3)
Head TubeNA105110115
Effective Seat Tube AngleNA76.3 (Rail 75.8)76.3 (Rail 75.8)76.3 (Rail 75.8)
Chain StayNA440440440
Bottom Bracket DropNA-39mm (Rail: -45mm) -39mm (Rail: -45mm) -39mm (Rail: -45mm)
Fork TravelNA130mm130mm130mm
Fork Offset NA515151
Axle to Crown NA537mm537mm537mm
Seat Post Diameter ---31.6mm31.6mm31.6mm
Headset Type---ZS 44mm 56mm Semi Integrated ZS 44mm 56mm Semi Integrated ZS 44mm 56mm Semi Integrated
Bottom Bracket Type ---Threaded 73mm BSA Threaded 73mm BSA Threaded 73mm BSA