Depending on how far back your mountain bike history knowledge goes, the Nukeproof Reactor name may be familiar. It was first used for an aluminum hardtail in 1996, when Nukeproof was still based in Grand Rapids, Michigan. Nearly 25 years later the model name has resurfaced, but this time it's being applied to a full-suspension, aggressive trail bike that's available with either 27.5" or 29" wheels.
The 27.5” Reactor has 140mm of rear travel and a 150mm fork, while the 29” version has 130mm of rear travel and a 140mm fork. There's also an RS version for both wheel sizes, which sees the fork travel bumped up by 10 millimeters.
Nukeproof Reactor Details
• Wheelsize: 29" or 27.5"
• Aluminum or carbon frame options
• Travel: 130 (29") / 140 (27.5")
• 2.6" tire clearance
• 12 x 148mm rear spacing
• Threaded BB
• Price: $2,729 - $5,399 USD
• Available: Late October 2019
Along with the two wheel size options, there are carbon and aluminum-framed models. This is Nukeproof's first full carbon frame – their previous carbon bikes used alloy swingarms. Now, even the aluminum bike gets carbon seatstays in order to shed a bit of weight.
Complete bike prices range from $2,750 for the aluminum Comp model up to $5,400 USD for the carbon RS edition. There's a healthy number of build kit options, with two complete aluminum models and four carbon models, along the option to go the frame-only route.
The Reactor is expected to be available by late October. Frame Details
Room for a water bottle inside the front triangle? Check. Threaded bottom bracket? Check. Those two important details are taken care of, and Nukeproof also equipped the Reactor with a generous downtube protector to ward of flying rocks and other debris, and enough room to fit 2.6” tires, or to run something smaller and have extra mud clearance.
The derailleur and brake housing are internally routed through the front triangle, but then emerges just in front of the bottom bracket and remains externally routed on the swingarm. That under-the-BB routing is a point of contention for some riders, but it is relatively uncommon to run into any issues with pinched or smashed housing – the chainring or crankarms are more likely to hit an obstacle first. On the topic of smashing into immovable objects, the Reactor also has ISCG 05 tabs for chain guide / bash guard mounting.Geometry
No matter the wheel size, the Reactor has a 66 or a 65.5-degree head angle depending on the position of the flip chip that's found on the seatstay. Flipping the the chip from the steeper 'Trail' to the 'Rail' position also drops the bottom bracket height by 6mm, and slackens the seat tube angle to 75-degrees.
On the RS models, the longer fork slackens the head angle to either 65.5 or 65-degrees, and the seat angle drops to either 75.1 or 74.6-degrees. The seat angle isn't as steep as what's quickly becoming the norm – we'll see what that translates to out on the trail once we get a Reactor in for review.
Reach numbers range from 451mm to 514mm for the 29” model, and 425mm to 516mm for the 27.5” option.Suspension Design
The Reactor's Horst Link suspension layout is similar to whats found on the Nukeproof Mega, but the kinematics have been altered to suit the Reactor's slightly more pedaling-oriented focus. Anti-squat sits at 92% in the 32/50 gear ratio, but it falls off fairly quickly as the bike goes through its travel in order to allow the suspension to work unimpeded on rougher terrain.
The Reactor has a 21% leverage ratio change, which is also a bit higher than the Mega. That was done in order to increase the amount of mid-stroke support and end-stroke ramp up – Nukeproof expect this bike to be ridden hard, and don't want riders to find themselves blowing through the moderate amount of travel too quickly. Models
Nukeproof's parts spec for the Reactor make its 'get rowdy' intentions clear. All bikes have a piggyback shock from either Fox or RockShox, and a 2.5" Maxxis Assegai / 2.4" Minion DHRII tire combo. A 200mm rotor and powerful brakes are also standard on most models as well - this isn't a bike that was made for casual cruising.• Reactor RS Carbon:
Carbon frame, RockShox Lyrik Ultimate / Super Deluxe Ultimate, SRAM Code RSC brakes, X01 Eagle drivetrain. $5,400 USD.• Reactor Factory Carbon:
Carbon frame, Fox 36 Float Factory / DPX2 Factory, Shimano XT brakes, drivetrain. $4,900 USD.• Reactor Pro Carbon:
Carbon frame, RockShox Pike Select / Super Deluxe Select, SRAM Guide RE brakes, GX drivetrain. $4,400 USD.• Reactor Elite Carbon:
Carbon frame, Fox 36 Performance / DPX2 Performance, Shimano SLX brakes, drivetrain. $3,800 USD.• Reactor Expert:
Alloy frame (carbon seatstays), RockShox Pike Select / Super Deluxe Select+, SRAM Guide RE brakes, NX drivetrain. $3,100 USD • Reactor Comp:
Alloy frame (carbon seatstays), RockShox Revelation RC / RockShox Super Deluxe Select R, SRAM Guide T brakes, SX drivetrain. $2,750 USD>
Where it all began. The 1996 Nukeproof Reactor.