Bird Aeris review

Can a British trail bike compete with the rest of the world?

Our rating 
4.0 out of 5 star rating 4.0
GBP £850.00 RRP

Our review

Top spec, excellent geometry and supportive suspension make the Aeris a ton of fun
Skip to view product specifications

Hampshire-based company Bird was created less than two years ago, and the 140/150mm Aeris is its first full-susser. It’s a brilliant start, and not just thanks to the fantastic value of the Canyon-style direct-sale model.

  • Highs: Climbs well, descends brilliantly, and the warranty is transferable
  • Lows: There’s noticeable flex across the low-braced back end
  • Buy if: You value geometry and suspension quality above swoopy looks

Frame and equipment: forward thinking

The Aeris is long and slack, Taiwan-built to Bird’s exacting specifications. It’s a bike after Mondraker’s heart, as it too puts the front axle where it should be – well ahead of the bars for huge stability. Our Large test ride has an elongated 640mm effective top tube and a dinky 35mm stem to keep the cockpit the right length.

Designed around a 35mm stem, the missing length is in the toptube. result? the bars stay where you need them, but the front axle moves well ahead:
Russell Burton

Designed around a 35mm stem, the Aeris’s missing length is in the top tube

With the Pike fork at 150mm and the rear at 140mm the head angle is 66.3 degrees, with the cranks a low 333mm (150mm rear travel adds 2mm and 0.2 degrees). We had no problems with ground clearance, thanks to notably progressive rear suspension that keeps the bike buoyed up in its travel.

Bird offers masses of build options, with even the standard bits coming as a pleasant surprise – all bottom brackets are XTR and all cassettes are XT, for instance, no matter which build. Also, unless you ask for tubes it comes set up tubeless, not just ‘ready’.

Ride and handling: low speed leaning

Once out on the trail, the plush and well-damped travel of the X-Fusion O2 RCX shock and Pike combine to brilliant effect. The Aeris pumps berms and pops off jumps with verve, and on anything from swooping singletrack to black-graded downhills, it’s stable, lively, communicative and incredibly fast. There’s a fair amount of flex across that low rear end, but it takes a lot of hammer to turn compliance into inaccuracy.

The aeris is lively and responsive – and demands to be ridden fast:
Russell Burton

The Aeris is lively and responsive – and demands to be ridden fast

The steering can flop on the heavily triangular Maxxis Minion 3C at very low speeds, but if you care about slow this isn’t the bike for you. Still, at just 13.2kg (29.2lb) it’s no monster, and the 1207mm wheelbase, pert rear suspension and well-forward forks mean it scales tricky climbs competently.

Problems? The ‘cinch’ on Race Face’s 2015 Turbine cranks slipped and the driveside came loose, but after being re-tightened it’s been totally solid. We’ve also snapped a flat spoke from the Sun Ringle Charger rear wheel, and there’s obviously no shop to return to. So what do you do?

“Warranty we mostly deal with by pictures and over the phone,” says founder Ben Pinnick. “As a rule we can make a decision then. We’d either send you a new frame (with a return label), or arrange for a local mechanic to check it out. We’re currently registering mechanics to be our warranty network.”


Unusually, the warranty is transferable between owners, and Bird offers five sizes – the same as Trek. Ordering now gets you a January delivery, and frame only (with X-Fusion O2 RCX shock, Hope seat clamp and Shimano 12mm axle) the Aeris is £850 / US$1,360 / AU$1,557.

Product Specifications


Name Aeris 1 (15)
Brand Bird

Description Prices for Frame only : 5 Shock options available
Seat Tube Angle 73.5
Head Tube Angle 66
Top Tube (cm) 64
Seat Tube (cm) 46.5
Chainstays (cm) 43.5
Wheelbase (cm) 121
Bottom Bracket Height (cm) 33.8