Bird Zero AM2 review

Long and low buy-direct trail flyer

BikeRadar score5/5

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. 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 1x11 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 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, 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

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 2x10 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.

This article was originally published in Mountain Biking UK magazine, available on Apple Newsstand and Zinio.

Seb Stott

Technical Writer, UK
Seb is a geeky technical writer for BikeRadar, as well as MBUK and What Mountain Bike magazines. Seb's background in experimental physics allows him to pick apart what's really going on with mountain bike components. Years of racing downhill, cross-country and enduro have honed a fast and aggressive riding style, so he can really put gear to the test on the trails, too.
  • Age: 24
  • Height: 192cm/6'3"
  • Weight: 85Kg/187 lbs
  • Waist: 86cm / 34in
  • Chest: 107cm / 44in
  • Discipline: Mountain
  • Preferred Terrain: Steep!
  • Current Bikes: Focus Sam 3.0, Kona Process 111, Specialized Enduro 29 Elite
  • Dream Bike: Mondraker Crafty with Boost 29" wheels, a 160mm fork and offset bushings for maximum slackness.
  • Beer of Choice: Buckfast ('Bucky' for short)
  • Location: Bristol, UK

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