Bird Aether and Trek Slash crowned Trail and Enduro Bike of the Year in our annual mega-test

We've hammered 16 of the hottest trail and enduro bikes of 2021. Now it's time to reveal the winners…

Bike of the Year 2021

Sixteen bikes, hundreds of kilometres of riding, and countless metres of climbing and full-throttle descending. After months of testing, it’s time to announce our first Bike of the Year 2021 winners – with the Bird Aether 9 crowned Trail Bike of the Year and Trek Slash 8 taking the Enduro Bike of the Year crown.

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Make sure you read our full Bird Aether 9 review and Trek Slash 8 review to get the in-depth verdict on why these are our top picks for 2021.

Here, we’ll give you a teaser of what makes these bikes so special and the inside track on how we put our 2021 Bike of the Year test together.

Bike of the Year is our industry-leading mega-test, now more than a decade old and ran by BikeRadar in conjunction with our colleagues at Cycling Plus and MBUK magazines, to deliver a verdict on the year’s best road and mountain bikes.

In short, we’ve tested dozens of the hottest bikes to see what’s really worth your money. (We’ll be announcing our road winners on Friday 14 April).

Our team gave this year’s bikes a proper hammering, riding everywhere from local laps of frozen-solid woodland singletrack and muddy, rutted tracks to the challenging terrain of BikePark Wales, where we were given private access to finalise our testing on closed trails.

BikeRadar and MBUK magazine’s technical editor-in-chief, Robin Weaver, once again took charge of the enduro category, pushing eight bikes to their limit, with Cotic, Kona, Nukeproof, Scott, Trek, Vitus, Whyte and YT all represented.

Cyclist in red shorts riding the Trek Slash 8 full suspension mountain bike
The Trek Slash 8 won out as our enduro winner, against competition from Cotic, Kona, Nukeproof, Scott, Vitus, Whyte and YT.
Andy Lloyd / Immediate Media

The £3,450 Trek Slash 8, revamped for 2021, prevailed, delivering an uncompromising balance of seat-of-your-pants descending performance and the all-round ride quality we still demand from an enduro bike.

“The Slash 8 strikes the perfect balance between a fun and lively feel, and ultimate chaos-calming composure,” says Rob.

Cyclist in rad and black riding the Bird Aether 9 full suspension mountain bike downhill
The Bird Aether 9’s all-round credentials see it take our trail bike crown.
Russell Burton / Immediate Media

Meanwhile, our technical editor, Tom Marvin, led the trail bike category, thrashing bikes from Canyon, Intense, Lapierre, Privateer, Propain, Saracen and YT, before awarding the Bird Aether 9 (£3,850 as specced) the top gong.

Tom’s verdict? “Whether you’re pinning it downhill or stretching your legs on the climbs, the Aether 9 delivers.”

Read on to find out how Rob and Tom tested this year’s Bike of the Year, how they choose their winners and, most importantly, for more on why the Bird Aether 9 and Trek Slash 8 took the top prizes.

The verdict

Trail Bike of the Year – Bird Aether 9

BikeRadar Trail Bike of the Year 2021 – Bird Aether 9
“Whether you’re pinning it downhill or stretching your legs on the climbs, the Bird Aether 9 delivers,” says Tom, our chief trail bike tester.
Russell Burton / Immediate Media

Technical editor, Tom Marvin: “The Bird Aether 9 delivers in every situation, from long days in the hills to short blasts in the woods. From its geometry to its suspension, its value to how easy it is to live with, it’s hard to look past this bike. Add the ability to customise the spec and the wide sizing range, and there’s an Aether 9 package for everyone.”

The contenders

A decent trail bike should also be fast and capable on the descents, but with less weight and travel (130–150mm) than enduro bikes, they’re nimbler on flatter trails, less of a drag on longer rides and better on the climbs.

The following bikes were shortlisted for our Trail Bike of the Year award, with a price range of £2,999.99 to £4,695.

  • Bird Aether 9 (winner)
  • Canyon Spectral 29 CF 7
  • Intense Primer 29 Expert
  • Lapierre Zesty AM CF 6.9
  • Privateer 141 SLX/XT
  • Propain Hugene
  • Saracen Ariel 30 Pro
  • YT Jeffsy Blaze 29

Enduro Bike of the Year – Trek Slash 8

BikeRadar Enduro Bike of the Year 2021 – Trek Slash 8
“The Trek Slash 8 strikes the perfect balance between a fun and lively feel, and ultimate chaos-calming composure,” says Rob, who led our enduro testing.
Andy Lloyd / Immediate Media

Technical editor-in-chief, Robin Weaver: “The Trek really did come in and surprise us. Every lap on the Slash was an eye-opener, and the more we pushed, the more it gave back in return… This thing can seriously shift! The Slash 8 strikes the perfect balance between a fun and lively feel, and ultimate chaos-calming composure.”

The contenders | Enduro Bike of the Year

With 150mm to 180mm of travel, enduro bikes are designed to be hurled down the roughest downhill tracks but still be pedalled back to the top. The best enduro bikes are still fun when riding less full-on terrain, too.

The following bikes were shortlisted for our Enduro Bike of the Year award, with a price range of £3,450 to £4,198.

  • Cotic RocketMAX Gen3 Silver SLX
  • Kona Process 153 DL 29
  • Nukeproof Mega 290 Pro
  • Scott Ransom 920
  • Trek Slash 8 (winner)
  • Vitus Sommet 29 CRX
  • Whyte G-180 RS 29er V1
  • YT Capra Shred 27.5

How we tested Bike of the Year 2021

This has been the strangest and toughest Bike of the Year test we’ve ever put together.

What’s made the 2021 test so tough? Our biggest issue was getting hold of bikes. The surge in cycling over the past year, coupled with delays brought about by the global pandemic and Brexit, meant it wasn’t easy to call in the models we wanted.

That’s why we have eight contenders each in the Trail and Enduro categories, rather than 10 as in previous years, and why pricing varies more than usual.

Bike of the Year 2021 with MBUK magazine
Once again, our Bike of the Year test is brought to you in conjunction with MBUK magazine.
Andy Lloyd / Immediate Media

We could have just included the most expensive bikes available, as these weren’t selling as fast as cheaper models, in a bid to shoehorn every major brand into the test – but, while we all enjoy lusting over the latest superbikes, it would have put the winners frustratingly out of reach for most readers.

Instead, we’ve stuck with our trail and enduro categories, and packed them with some of the most exciting bikes on the market. While these aren’t cheap bikes by any stretch of the imagination, and they may require some serious saving-up, hopefully they won’t completely break the bank.

We think these bikes hit a sweetspot between attainable pricing and all-out performance. Importantly, most are available in cheaper or more expensive builds, to suit your budget.

Meet the tester – Tom Marvin

Keen on Lycra-clad XC laps, as well as rooty off-piste, Tom is well-placed to rate the all-rounders that make up our Trail Bike of the Year test.

Tom Marvin profile pic
Russell Burton / Immediate Media

The criteria

Our trail bike category – arguably the toughest to define – includes machines costing between £2,999.99 and £4,695 (thanks to one bike coming with the wrong spec and another’s price being pushed up), and spans rear wheel travel from 130mm to 150mm.

The way we see it, the winner should be more than capable of accompanying you on an all-day XC epic, but you wouldn’t wince at the prospect of tackling the odd enduro race on it or even taking it on an alpine holiday.

Enduro bikes are easier to categorise. If you’ve ever watched high-profile events such as the Enduro World Series, you’ll know these machines are designed for hauling uphill and then pummelling back down, time and time again.

That means they still need to feel comfortable when pointed up the side of a mountain, but possess all the poise and control of a scaled-down downhill bike when it comes to racing back down. Pricing for this category runs from £3,450 to £4,198, while travel varies from 153mm all the way up to 180mm.

Meet the tester – Robin Weaver

With plenty of international racing experience, Rob knows what makes a good descender and led our Enduro Bike of the Year test.

Robin Weaver
Andy Lloyd / Immediate Media

From our local tracks to BikePark Wales

Bike of the Year 2021 testing at Bike Park Wales
Having completed their initial testing on local trails, Rob and Tom headed to BikePark Wales.
Andy Lloyd / Immediate Media

Once we’d sorted the bikes, the next hurdle was complying with social-distancing rules and travel restrictions. These precluded our regular tester Sarah Gamsjäger from adding her input, as in years past.

We also needed to work out how to test the bikes effectively while staying local, until our friends at BikePark Wales offered to host some private testing sessions. Although this required some (work-related) travel, it meant there would be zero risk of coming into contact with other trail users and potentially spreading infection.

As ever, we’ve spent countless hours riding, tinkering, riding some more, measuring, then riding even more, to establish a winner in each category. And it’s really not been easy.

While in previous years, two or three bikes stood head and shoulders above the rest, it now feels like the playing field is the most level it’s ever been.

We’d ridden a number of this year’s Bike of the Year contenders before, albeit in different builds, so had a good idea of what to expect. We then set about testing them back-to-back in a number of locations – including the home trails we know like the back of ours hands – to ensure we knew how each bike behaved with different terrain beneath its wheels.

Bike of the Year 2021 testing at BikePark Wales
Flat-out fast! There’s no holding Tom and Rob back when it comes to Bike of the Year testing.
Russell Burton / Immediate Media

Then it was time to head to BPW, where we could really push them on some familiar tracks, which helped when it came to making those all-important final decisions.

We’re confident we’ve found the right winners for this year’s test, and two bikes that fully deserved to earn their Bike of the Year crowns.

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Now the winners have been announced, we’ll be continuing our Bike of the Year coverage through April and May, with full reviews on all of the 2021 contenders.

Thanks to…

A massive thank-you to BikePark Wales for granting us access to its trails despite the bike park being closed to the public.

Cheers also to Fox clothing for sorting the kit for the photo and video shoots and Garmin for sorting us out with bike computers to log the many miles of testing.

And not forgetting Muc-Off, for its help keeping the bikes washed and lubed throughout testing.