NUKEPROOF REACTOR PRO 290 ALLOY £3,699.99
There are a ton of different variants of the Nukeproof Reactor. You can pick either 27.5in or 29in wheels, carbon or aluminium frames and multiple price points in each category. Travel is matched to wheel size, so the 27.5in Reactor gets a 150mm fork and 140mm out back while our 29er test bike has 10mm less travel at both ends.
To reduce weight, Nukeproof uses triple-butted hydroformed aluminium tubing but with a carbon-fibre seatstay assembly. This carbon upgrade makes the rear suspension more sensitive by reducing unsprung mass, but we reckon it also improves the ride feel. Yes, heavier riders may find the Reactor a little too flexy, but for riders of average weight the stiffness and comfort from the chassis is spot on.
Geometry is on the money too. It has a similar reach to the Specialized and Whyte, and while the head angle is steeper and the BB higher, you can shave 6mm off the latter and half a degree off the former, using the built-in (Trail/rail) flip-chips. These inserts stay captured in the frame when you make the adjustment which is a nice touch.
SUSPENSION
Even though the 130mm rear suspension on the Pro 290 Alloy looks similar in layout to the Focus, it is a four-bar design with completely different kinematics. Once into the travel the Nukeproof has much more support, so you get none of that wallow under power. And even though we measured the rear travel at 127mm, it’s so effective it actually feels like it delivers more.
The Rockshox Pike Select+ fork has a slightly different spring curve to the Lyrik on the Whyte but it was a good fit for the rear suspension on the Pro 290 Alloy. We did bottom it a few times on our first downhill runs, so we added a Bottomless token and ran a little less sag. Even then the Pike doesn’t feel as stiff as the Fox 36, but we reckon the flex compliments the ride of the Pro 290 Alloy frame.
COMPONENTS
Like all Nukeproofs, the cockpit on the Reactor employs the smaller
31.8mm interface, but again this adds to the overall ride feel. The Nukeproof handlebar has a good profile, and the 45mm stem length matches the reach on the size L Reactor perfectly.
The Brand-x Ascend post has 170mm of drop but the seat tube on the Reactor is a little taller than the other bikes in its class, so if you’re of medium height the saddle could be too high at full extension. Something worth considering when choosing which size to get.
Even when the SRAM Guide RE four-piston brakes had bedded in, the Nukeproof felt a little under-braked at the rear. It has a smaller 180mm rotor so if you’re a heavier rider we’d recommend upgrading to a 200mm rotor. Changing the Maxxis Dissector rear tyre could also help as it doesn’t quite have the braking traction of a Minion DHR II or High Roller II. Nukeproof runs the tougher EXO+ casings to ensure you’re not going to be smashing the rims, which is a good thing as the 28mm internal width is slightly narrower than those elsewhere to cut rotating weight.
PERFORMANCE
On paper, the Pro 290 Alloy is more upright than the other three bikes in the shop bought category. And when you’re charging downhill at full pelt, the ride can get a bit wild. But that’s hardly surprising because the bike has a generous 481mm reach, good tyres and decent cockpit that really egg you on.
Even having less travel isn’t a limiting factor. On the flipside it’s more agile and accurate on mellow singletrack, and when you’re darting in and out of the trees, popping off roots and rocks, it is the most fun here and the easiest to ride with confidence.
It climbs well too, and even if there’s a bit more suspension movement than on the Specialized, it’s still really efficient so you never feel like you’re working overly hard on the way up.
A little lightweight for burlier riders
Superb balance, insanely fast singletrack shredder
You’d think with less travel the Nukeproof Reactor Pro 290 Alloy would be muscled out by the Whyte and Specialized, but it’s able to hold its own because Nukeproof has totally nailed the geometry, suspension and ride feel. So if you’re a lighter rider that’s focused on shredding singletrack rather than bike parks, this is a superb mid-travel trail bike. It’s also the only one where we wouldn’t change a thing (okay maybe a token in the fork) but no major upgrade, tweaks or custom tunes. The Reactor
Pro 290 Alloy is literally dressed for success from the off.
When we tested the original alloy Stumpy EVO it was cutting-edge in terms of geometry, even if it was limited to two sizes – S2 and S3. And as cool as that bike was, we struggled a bit with the performance.
Fast-forward to today and Specialized offers the latest Stumpy EVO in six sizes from S1 to S6. It’s also re-jigged the rear suspension, overall geometry and added a ton of adjustment. You can tweak the head angle independently of the BB height, and it also has two chainstay lengths and BB heights via the flip-chip Horst-link pivots. In fact, the geometry of just one frame size has 12 permutations, and thankfully for us, Specialized has a geometry finder on its website because we really didn’t have room to list all of the different measurements on the spec page.
It’s also possible to convert the 29er to a mullet by swapping to a 27.5in rear wheel and fitting a different shock link which costs £70. And because the S-sizing is based on the length of the bike rather than the height of the seat tube, swapping between frame sizes could not be easier.
With so many options we haven’t ridden every single setting, nor have we used the 27.5in link to mullet the bike. The main reason is because the geometry felt great with the stock head angle in the long/low chainstay/bb setting and those are the numbers you see printed here.
SUSPENSION
Specialized has also increased travel on the rear to 150mm. We measured it