Bird Aether 7 (Custom Build) review

It looks rad on paper, but how does this short-travel trail ripper ride in the wild and stack up as one of our Trail Bike of the Year contenders?

Our rating

4

3370.00

Dan Milner / BikeRadar

Published: April 14, 2020 at 9:40 am

Our review
Perky-pedalling, confidence-inspiring big-hit trail bike for fans of smaller wheels

Pros:

No slouch on the climbs, super confident on descents

Cons:

Not the smoothest ride ever, smaller wheels rob speed in some situations

The Aether 7 is Swinley-based Bird’s latest trail machine; a 130mm travel aluminium bike that sports 27.5in wheels, a 140mm fork and radically long geometry.

We first saw the Aether 7 at the back-end of 2019, and it was on its launch that I picked up my test bike.

Value is high with Bird, thanks to its direct sales model and, as with an increasing number of brands these days, the specification of the bike is customisable at the point of purchase.

For our 2020 Trail Bike of the Year test, Bird built me a bike just shy of the £3,500 limit.

Bike of the Year 2020

The Bird Aether 7 is part of our annual Bike of the Year test.

Head to our Bike of the Year hub for the full list of winners, categories and shortlisted bikes, as well as the latest reviews – or read our behind-the-scenes feature on how we tested Bike of the Year 2020.

Bird Aether 7 frame

The raw-finished (paint options are available) aluminium frame has a no-frills feel to it, and that’s not without its benefits.

All the pivot hardware is easy to access and there’s plenty of information on bearing diameters and pivot bolt torques available.

Cable routing is external, routed along the top of the down tube and clamped securely in place, making maintenance in the long run much easier, though at the expense of a cleaner look. A threaded bottom bracket is a further nod in the mechanic’s direction.

The 130mm of suspension is controlled by a four-bar linkage, with the intention to give good pedalling characteristics around the sag point and a progressive kinematic for additional control on bigger hits.

The shock pushes into the top tube, leaving room for a bottle cage within the main triangle.

Bird Aether 7 geometry

Bird Aether 7
The Bird Aether is new for 2020. - Dan Milner / BikeRadar

Bird has been known for its progressive geometry since it was first seen around seven years ago. On paper, the Aether 7 looks to be a properly aggressive trail bike, with super long and low geometry across its five sizes: S, M, M-Long, L, XL.

While front ends are long, seat tubes are suitably short, meaning riders looking to ‘size-up’ should be able to fit, even with a longer drop dropper post.

At 182cm, I tested a Large, and while I got on well with the bike’s shape, I may have picked a Medium-Long based on the geometry sheet alone.

However, as you’ll read, the longer geometry of the Large caused me no issues on the trail and sizing felt good – thanks, I believe, to the steep-ish 76-degree seat angle.

  • Sizes available (* tested): S, M, M-Long, L*, XL
  • Seat angle: 76 degrees
  • Head angle: 65 degrees
  • Seat tube length: 44.5cm / 17.52in
  • Top tube (effective): 65.5cm / 25.79in
  • Chainstay: 42.5cm / 16.73in
  • Wheelbase: 1,240mm / 48.82in
  • Bottom bracket height: 32.5cm / 12.8in
  • Standover: 68.6cm / 27.01in
  • Head tube length: 12cm / 4.72in
  • Reach: 50.4cm / 19.84in
  • Stack: 60.4cm / 23.78in

Bird Aether 7 specifications

Bird’s UK-based assembly operation means individual bike specs are possible via its website. As such, each bike can be tailored to the purchaser’s individual preferences or budget.

My £3,370 bike came with RockShox Ultimate level suspension with a 140mm Pike up front and a Deluxe rear shock.

The drivetrain and brakes were Shimano’s new 12-speed XT gears and four-pot brakes, with 200mm/180mm rotors. These were mounted to the new MicroSpline freehub on the Hope Pro4 hubs, built into DT Swiss XM481 rims.

I chose Maxxis Minion tyres to wrap up the rims with CushCore tyre inserts installed, and the finishing kit came from RaceFace, along with a 170mm Bird-branded dropper post.

Bird Aether 7 ride impressions

Our 2020 Bike of the Year testing predominantly took place in the South West of the UK through winter. This included loops around trail centres, natural muddy and rooty tracks dug in to Welsh hillsides, as well as laps at BikePark Wales.

A number of bikes were taken to Spain for the final set of tests, where we rode on dry, rocky flow trails, super-technical rock gardens and some loamy enduro tracks. Thanks to BlackTown Trails for their help with finding these test tracks!

The Aether 7 was very quick and easy to set up, with the RockShox Pike and Deluxe suspension being some of the easiest out there to set up and ride.

Bird Aether 7 climbing performance

A brief scan of the geometry chart and a peek at the tyre logos and CushCore valve suggest that the Aether 7 might be a little sluggish up the hills. However, with the suspension linkage providing plenty of anti-squat when sat pedalling, the Aether 7 surprised me with its eagerness to get to the top of the hills – certainly when the climbing mostly took place on fireroad drags and smooth singletrack.

This was further helped by the 76-degree seat angle, which puts your hips nicely over the cranks in a naturally powerful position that’s comfortable on long climbs.

On tarmac climbs, or when I wanted to crank the bike out of the saddle, the lockout switch on the shock came in handy to prevent what little bob there is showing its face.

On steeper climbs, the Aether 7 was a bit of a mixed bag. The short 425mm chainstays mean pivoting the bike round up-hill switchbacks is easy, as is getting the front end to shimmy up a step in the trail.

However, on looser sections, it’s necessary to balance rear wheel traction with front end precision – longer stays may have boosted grip out back.

I also found that the smaller wheels choked up a little more when muscling the bike up rougher climbs. As such, I feel that the Aether 7’s best suited to smoother drags, rather than the most technical climbing challenges. It won’t flatter your technical climbing ability, but it shouldn’t entirely hinder it either.

Bird Aether 7 descending performance

Much like on the climbs, the Aether 7 showed many sparks of brilliance on descents, but also areas where it lacked.

Shimano XT brakes on the Bird Aether 7
Shimano provided the four-pot XT brakes on this custom build. - Dan Milner / BikeRadar

My first ride on the bike was at a typical UK trail centre, with beautifully manicured berms, drops and flowing singletrack on relatively smooth trails.

Here, the Aether 7 ripped and was fast, confident and stable. The slack head angle, long reach and grippy front tyre meant it was really happy being tipped into a turn, where the shoulder tread could engage the dirt and fire you towards the exit without the need to tickle the brakes.

On the straights, it was a case of letting go of the brakes and hanging on, generating speed through pumping the well-supported rear suspension, or jabbing at the pedals to boost speed even further.

The fork and shock are smooth and controlled, and easy to set up, while the Shimano XT brakes, on this bike at least, performed faultlessly throughout testing, with sharp, predictable power.

The Aether 7 also shined on steep, loamy, wooded tracks. With the saddle dropped 170mm towards the dropper’s collar it’s well out of the way, letting you get your weight back as the bike is pointed towards the catch berm below.

Cyclist riding full suspension mountain bike
Over rocks, the smaller wheels are noticeable. - Dan Milner / BikeRadar

The slack head angle punts the front wheel nicely in front of the bike, and with the Pike’s chassis more than stout enough to deal with most turning forces you’ll put its 140mm of travel through, it’s a steadfast feeling front end that you can bury into a corner.

The rear suspension isn’t the smoothest over mid-sized chatter, but if you bang it over bigger hits its progression through the stroke is nicely controlled, so the bump-stops are rarely troubled.

As such, on smoother, loamy or muddy tracks, the Aether 7 oozes confidence, allowing you to concentrate on where the next chute or corner is about to appear.

Cyclist riding full suspension mountain bike
The Aether 7 was one of the best cornerers in our Trail Bike of the Year test, where it absolutely railed. - Dan Milner / BikeRadar

Where it doesn’t shine so much is on rougher, rocky, more shallow terrain.

The 27.5in wheels noticeably get caught on edges, stealing momentum and speed, so to maintain the same pace I had to work the bike harder, picking smoother lines and making sure the harshest of edges were avoided.

When you need to get on the pedals, the rear-end helps drive the bike forwards because there’s minimal wallow thanks to its support.

Bird Aether 7 bottom line

Bird's Aether 7 is a really, really good bike. It surprised me with its climbing capabilities. While 130mm of travel does suggest a more trail-focused bike (which by deduction should be good up hill), the shape and kit on the bike suggested otherwise, which proves first impressions don’t always count.

On the right hill, it’s stable and peppy, and shouldn’t hold you back an ounce. On rougher climbs it’ll suffer, but I don’t think that’s what this bike is about.

Cyclist riding full suspension mountain bike
On smooth loam the Aether 7 stood out from the crowd. - Dan Milner / BikeRadar

Downhill, again, in the right places, it’s fantastic. If I were to ride steep, muddy, rooty tech in South Wales this is the bike I’d reach for. It’s long, low and slack, with a grippy front tyre pushed well in front of the handlebars.

On steep stuff, the small wheels are nimble, so threading the bike between trees is an easy game.

If you ride in relentlessly rocky areas, though, where carrying speed is the name of the game, the 27.5in wheels may hold you back compared to bigger-wheeled cousins.

Fortunately, there are plenty of options out there, including the excellent Bid Aeris AM9.

With thanks to...

BikeRadar would like to thank 661, IXS, Leatt, Garmin, Facom and BlackTown Trails for their support during our Bike of the Year test.

Product

Brandbird
Price3370.00 GBP
Weight14.4900, KILOGRAM (L) -

Features

ForkRockShox Pike Ultimate, 140 mm (5.5in)
br_stemRaceFace Turbine 40mm
br_chainShimano XT
br_frameAluminium 27.5in, 130mm (5.1in) travel
TyresMaxxis Minion DHF, 3C-EXO, MaxxTerra, 27.5x2.4", Maxxis Minion DHR II, 3C-EXO, MaxxTerra, 27.5x2.4"
br_brakesShimano XT, 203/180mm rotors
br_cranksShimano XT, 32t
br_saddleFabric Scoop
br_wheelsDT Swiss XM481 rims on Hope Pro4 hubs
br_headsetBird
br_shifterShimano XT
br_cassetteShimano XT
br_seatpostBird Down Dropper, 170 mm
br_gripsTapeGusset S2
br_handlebarRaceFace Next R, 780mm
br_rearShockRockShox Deluxe Select+
br_bottomBracketShimano
br_availableSizesS, M, ML, L, XL
br_rearDerailleurShimano XT