Bird Zero AM2 review

Long and low buy-direct trail flyer

Our rating 
5.0 out of 5 star rating 5.0
GBP £1,230.00 RRP

Our review

With aggressive geo and a sublime fork and tyres, this flying hardtail could get some full-sussers in a flap
Buy if, You want an asskicker of a hardcore hardtail that'll take on full-sus machines when the going gets gnarly
Pros: Long, low and slack geometry inspires confidence everywhere; supple, supportive and adjustable fork; great stock spec, plus pick’n’mix parts to suit your tastes/budget; enough clearance for masses of mud or really fat rubber
Cons: Could benefit from even wider rims
Skip to view product specifications

Bird is a small UK brand whose direct-sales model affords great value, as well as customisation of parts to order. The Zero AM is Bird’s long-travel hardtail – and the bike that really helped the firm take off.


Transferable lifetime warranty

The 6061-T6 aluminium frame comes with a lifetime warranty that’s transferable to a new owner should you decide to sell it on. It features routing for the latest side-swing front derailleurs and stealth droppers, as well as ISCG-05 tabs for a chain guide.

Even with a 2.4in rear tyre there’s ample mud clearance. bird claim tyres up to 2.8in will fit:

Even with a 2.4in rear tyre there’s ample mud clearance

Clearance is huge – Bird claims it’ll take 2.8in plus-size rubber should you wish, but we didn’t try this out. Our pre-production sample’s seat tube had been reamed too tight, scratching the seatpost, but Bird assures us that the final frames won’t have this issue.

While we were more than happy with the standard Shimano SLX/Race Face build kit, Bird’s clever sales model lets you swap or upgrade components. We chose a fast but forgiving 2.4in Maxxis Ardent rear tyre and a corner-hugging 3C Minion DHF up front, for a £5 surcharge on top of the £1,125 base price. You could also opt for a dropper or 1×11 gearing, depending on how far you’re willing to dip into your nest egg.

Long, low and comfortable ride

Jumping aboard the Bird, especially during back-to-back testing, it immediately feels long, low and comfy. The 780mm bar certainly helps (there’s an even wider 800mm option too), but the super-long top tube is the key. For me, at 6ft 3in / 190cm this meant a really comfortable fit and extra breathing room on the climbs.

The zero am is an astoundingly fast, confident and fun ride:

The Zero AM is an astoundingly fast, confident and fun ride

The 74-degree seat angle is steep enough to let you attack the toughest pitches, and the long front end means you can slide the saddle forwards for maximum climbing comfort without the cockpit becoming too cramped.

Even at our control pressures, the 2.4in rear tyre we selected provided almost 29er levels of comfort when riding seated over rough sections. Bird will also post your bike with the tyres installed tubeless, allowing you to run lower pressures straight out of the box.

If we’re being fussy, we’d like to see Bird offer a wide-rimmed wheel option (such as Easton’s Heists) to maximise the bike’s low-pressure potential, but at least the standard 23mm Race Face Æeffect wheels are tough and light.

Confident swagger in the rough stuff

The long wheelbase (1,223mm on the XL size) and planted front end help the Zero AM rip through rooty, technical sections with a confidence and verve that make it feel more like a full-sus than other aggro hardtails from Kona, Ragley and Commencal we tested alongside it.

X-Fusion’s sweep rc hlr fork is a real highlight at this price, offering great support and tracking when riding hard:

X-Fusion’s Sweep RC HLR fork is a real highlight at this price

Railing round pitted, rocky corners, the beautifully controlled X-Fusion Sweep fork kept the tacky front tyre pressed into the ground, delivering smooth, predictable traction and impressive exit speed. We dialled on plenty of low-speed compression damping, which gave good support and allowed us to lean on the front end for maximum grip and control, but left the high-speed adjuster almost fully open so the fork remained sensitive to square-edged hits. Set up this way, its Roughcut HLR damper delivered sublime performance.

Bombing down rough downhill runs, the slack front end comes into its own. The large-volume back tyre takes a little of the sting out of the rear too, helping to balance out the mismatched feeling that long-travel hardtails can suffer from. The long front triangle and wide bar gave us the confidence to weight the front end more in techy sections.

The slack front end comes into its own when it’s time to hit the steeps:
Steve Behr

The slack front end comes into its own when it’s time to hit the steeps

Although the frame could be even tauter, the wide, stiff bar combined with the low overall weight and light wheels means the Bird is a relatively snappy sprinter. If you wanted to save even more weight you could easily upgrade to a 1x transmission, but our 2×10 SLX set-up worked a treat.

Perhaps appropriately, the Bird also inspired confidence when airborne. Yes, the Zero’s long wheelbase was likely to suit our tall main tester, but this style of long, slack geometry has been well-proven on full-sus bikes. When combined with the superb parts list, this translates into an astoundingly fast, confident and fun trail bike. Put simply, the Bird gives you the best shot at keeping up with your fully-suspended mates on gnarly trails, or even stealing their Strava KOMs.

Also consider:

Commencal Meta HT AM

Sporting a 160mm travel fork and a dropper post, the Meta HT AM is billed as a ‘semi-rigid enduro bike,’and wants to get rowdy when the trail points down. Read our full Commencal Meta HT AM review.

Vitus Sentier VRS

Get rowdy without the rear shock on Vitus’s remarkably sorted and well-equipped, ready-to-riot hardtail. It’s for those who like to really connect with the trail. Read our full Vitus Sentier VRS review.


Ragley Mmmbop 27.5

Fancy grabbing hold of a hard-edged, corner-carving beast of a hardtail and mostly pointing it down hills? Read our full Ragley Mmmbop 27.5 review.

Product Specifications


Name Zero AM2
Brand Bird

Available Sizes S M L XL
Weight (lb) 27.09
Saddle Charge Spoon
Seat Angle 74
Seatpost Race Face Ride (rigid)
Shifters Shimano SLX (2x10)
Stem Race Face Chester 35, 40mm
Weight (kg) 12.29
Spoke Type Black, stainless steel, bladed
Rear Wheel Weight 2300
Bottom Bracket Height (in) 12.17
Chainstays (in) 16.73
Seat Tube (in) 19.69
Standover Height (in) 27.13
Top Tube (in) 23.62
Wheelbase (in) 48.15
Rims Race Face Æffect
Rear Tyre Maxxis Ardent EXO TR 27.5x2.4in
Bottom Bracket Shimano Deore XT
Front Derailleur Shimano SLX
Brakes Shimano SLX M675, 180mm/160mm rotors
Cassette Shimano Deore XT, 11-36t
Chain KMC X10
Cranks Shimano SLX, 24/38t
Fork X-Fusion Sweep RC HLR, 150mm (5.9in) travel
Frame Material 6061-T6 aluminium
Front Hub Race Face Æeffect (100x15mm)
Rear Hub Race Face Æeffect (142x12mm)
Front Tyre Maxxis Minion DHF 3C Maxx Terra EXO TR 27.5x2.3in
Front Wheel Weight 1900
Grips/Tape Fabric XL
Handlebar Race Face Chester 35, 780mm
Head Angle 65.4
Headset Type Cane Creek 40, semi integrated
Rear Derailleur SLX Shadow Plus
Frame size tested XL