2014 Nukeproof Mega AM 275 Pro

(discontinued)

Reviewed by Evan Turpen and Jess Pedersen // Photos by Shawn Spomer and Lear Miller

Following a major overhaul to the tubeset, linkage, and shock tune in 2013, the 160mm travel Nukeproof Mega AM once again sees updates for 2014. When the company sat down to redesign the bike, they made it a goal to maintain the same stable, do anything feel from 2013, but with the added benefit of 27.5-inch wheels. Curious to see just how wild we could get on the revised ride, we did our best to put it through the paces in Sedona, Arizona during the 2014 Vital MTB Test Sessions. After all, any bike named after the famous mass-start Megavalanche race better have the guts to back it up.

Mega AM 27.5 Pro Highlights

• Hydroformed double-welded T6 6061 aluminum frame
• 27.5-inch wheels
• 160mm (6.3-inches) of rear wheel travel
• True 44mm headtube diameter
• 66-degree head angle
• 73.5-degree seat tube angle
• -3mm bottom bracket drop
• 445mm (17.5-inch) chainstay length
• ISCG05 tabs
• 73mm bottom bracket shell
• 142mm x 12mm thru-axle
• Measured weight (size Large, no pedals): 31-pounds 14-ounces (14.46kg)
• $5,503.99 MSRP

From the square shaped hydroformed tubeset to the oversized pivot bearings, CNC-machined bottom bracket assembly, huge chainstays, and massive welds throughout, everything about the Mega AM 275 screams robust. The scale says the same, registering a hefty 31.9-pounds - just 3-ounces less than the heaviest of the 25 bikes we tested in Sedona. The bike isn’t shy about it though, and a quick glance at the spec sheet and geometry shows that it’s clearly intended to be an all-out brawler.

While the changes from 2013 may be subtle, Nukeproof had to update every tube in order to keep the same ride qualities from year to year. In the end, they managed to maintain the same bottom bracket and bar height by making slight adjustments here and there. They also extended the chainstays from 430mm to 440mm to make room for the new wheels.

Dubbed the “Erosion Linkage” suspension system, the linkage actuated single-pivot design yields 160mm of travel. It’s slightly regressive up to the sag point, then gets very progressive through the end of the stroke. The high-volume RockShox Monarch Plus RC3 shock is easily accessible with the compression lever positioned well for on the fly adjustments. All bearing and pivot seats are machined after the frame is built to ensure perfect alignment and the most supple suspension.

As you’d expect for any UK-based brand, mud clearance is excellent. Thanks to a large, curved tube that connects the seat stays in front of the seat tube instead of the typical seatstay bridge, there’s ample room for meaty tires and as much mud as you dare ride through.

External bolt-on guides on top of the downtube make for quiet and secure cable routing as well as easy maintenance. Nukeproof provides partially internal routing for the RockShox Reverb Stealth dropper post, cleaning things up nicely. The lower cable guide bolts serve as a water bottle mount inside the front triangle. Additional details include ISCG 05 chainguide mounts, a 142x12mm rear axle, and direct mount for the optional front derailleur.

The Mega AM 275 is available in sizes Small through XL in Pro and Comp builds that’ll run you $5,503.99 or $4,299.99, respectively. A frame and shock only option is also available for $2,235.99.

On The Trail

Sedona, Arizona’s Girdner to Last Frontier loop served as a good introduction to the Mega AM 275, offering a mix of technical and wide open sections. Later we enjoyed several laps on Brewer and Ridge trails, both of which served up plenty of high-speed gnar to see what the bike was capable of in more demanding situations.

The stock cockpit feel was spot on for a bike of this size and intended use, meaning that we didn’t need to change a thing. Nukeproof gets it - the stem was short, but not too short and the 760mm bars were wide, but not too wide. Even with the short stem there was plenty of room to move around on the bike with its spacious feeling top tube and reach. The rider position was also pretty neutral allowing for easy movements forwards or back to weight the bike.

Right off the bat it was clear that the Mega AM comes alive when pointed downhill. We were pleased with the properly slack 66-degree head angle, which was spot on for aggressive riding. Aided by the long-ish 17.5-inch chainstays, the stiff frame handles well at all speeds without feeling sketchy. Although this length adds to the bike’s overall stability, we can’t help wondering if it’d be more playful and snappy with something a hair shorter. Getting the front end up off the ground was a bigger task than we expected.

Thanks to the centered/neutral riding position it does change lines well, but the Mega AM also doesn’t have the most precise or responsive feel. It’s more of a point and shoot ride that allows you to get away with a lot, and is confidence inspiring in a monster truck kind of way. Though it does move along well at a casual pace, the geometry is best suited to being ridden hard and with very clear intentions. The stout frame gives assurance that it’ll hold up to the abuse. It all feels almost downhill bike-esque - surefooted, slightly sluggish, a little heavy and about average as far as rolling speed, but ready to rally through anything and everything in the trail.

Small bumps, square edge hits and trail chatter are all absorbed decently by the Nukeproof’s back end, although we felt if the wheels/tires were lighter that it would be able to respond quicker. G-outs, drops, and jumps are also absorbed well, encouraging you to let it rip down the trail. The RockShox Pike fork's stiffness and buttery smooth feel paired well with the frame. The main downfall of the rear suspension is while pedaling and sprinting hard, but for some riders the downhill performance will make up for this.

Out of the saddle under hard sprinting efforts the Mega AM is slow to respond, bobbing a bit with a definite feeling of power loss. Seated, however, it’s a surprisingly efficient climber, although it works best with the rear shock’s compression lever set to the middle firmness setting. The bike’s efficiency comes mainly from its excellent traction, roomy cockpit, and neutral climbing position. The slack front end did feel slightly off balance on slow tech climbs, but the long reach and 73.5-degree seat tube angle put us in a good place for climbing. The front end stayed planted pretty well up steep technical climbs and the bottom bracket height was high enough that clipping pedals on rocks was never an issue yet low enough to corner quite well.

Build Kit

The Mega AM 275 Pro has a solid and very well rounded spec. There’s not really anything that needs changing for the rider looking to take advantage of all 160mm of bump-gobbling travel the bike offers.

Maxxis High Roller II tires front and rear cornered well, provided excellent braking traction and were good in all types of conditions. The rolling resistance of the more aggressive tread is the only real negative. The amazing performance everywhere else more than makes up for this compromise.

Nukeproof’s Generator AM wheelset wheels are plenty strong, wide and stiff. They add to the bike’s charge over anything attitude, but the weight penalty robs the bike of quick acceleration. There also appears to be no provisions for an easy tubeless conversion. The 30-point engagement is great, though, making technical climbs more enjoyable.

We were once again impressed by the Avid Elixir 9 Trail brakes. They worked surprisingly well with plenty of power. The modulation was better than most, but ramped up fairly quickly from light braking force to full lock. We never experienced any fade and the lever feel is some of the best in class.

The bike comes with a dedicated 1x10 drivetrain and a chainguide, helping to keep the cost down while still offering a decent range of gears and reliable chain retention. With the fully enclosed Truvativ X0 chainguide there never were any dropped chains and everything spun smoothly with little to no drag. The only thing some may want to change is downsizing the front chainring from a 36 to a 32 or 34 tooth for a lower climbing gear. Noise was minimal thanks to the SRAM X0 Type II clutched derailleur and removable chainstay protector.

Long Term Durability

One quick look at this bike and you know it was built with durability in mind. It’s a burly bike with reliable components throughout, and will likely withstand many seasons of use with minimal maintenance. Nukeproof backs the frame with a two year warranty.

What's The Bottom Line?

The Nukeproof Mega AM 275 Pro is a dependable, overbuilt bike that’s geared towards hair-raising descents. Of all the 2014 bikes we threw a leg over during our Test Sessions, it felt more like a downhill bike than all the others. It’s long, low, and slack with a point-and-shoot ride that inspires confidence. The suspension design isn’t anything special, but it gets the job done and keeps the cost reasonable. Overall it’s a solid ride that wouldn’t be out of place lining up for the Megavalanche or even dropping into Whistler’s most challenging trails, making it a do-it-all rig for the gravity lover. The fact that you don’t have to swap any parts out to get the most out this bike is a major plus as well. Those more concerned with strength and long term durability than weight and pedaling efficiency will love this bike. The more chunky, rough, and steep your trails are the better.

Visit www.nukeproof.com for more details.

Bonus Gallery: 24 photos of the 2014 Nukeproof Mega AM 275 up close and in action

About The Reviewers

Evan Turpen - Evan has been racing mountain bikes as a Pro for the last 8 years with his career highlight being selected to represent the U.S. in the 2006 World Championships. More recently he can be found competing in enduro races and having a blast with it. He has helped design, develop, and test products for multiple major mountain bike companies and has an attention to detail well above most.

Jess Pedersen - Jess is one of those guys that can hop on a bike after a snowy winter and instantly kill it. He's deceptively quick, smooth, and always has good style. He's also known to tinker with bikes 'til they're perfect, creating custom additions and fixes along the way. Maybe it's that engineering background...

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