Bird's 5-star all-mountain hardtail gets reworked for 2018
Not many bikes get a full coveted 5-star review from the BikeRadar test team, but Bird managed that with its Zero AM2 hardtail last year. Not one to rest on its laurels though, it’s back with a revised Zero AM Boost.
It probably won’t take a genius to work out at least one of the revisions on the new bike — you just need to look at the model’s name. Yep, Bird’s aggressive, long travel hardtail now comes with a boost-width back end.
How much this really matters, in terms of wheel stiffness and ride quality, is up for debate, however with the industry pushing it as a whole it makes sense for Bird to make this revision. At the very least, it makes speccing and/or upgrading the bike with the latest wheel products a whole lot easier in the future.
We’ve already found that having a boost fork and non-boost frame makes it a bit of a pain getting new hoops with Tom’s long-term Transition Scout, and most modern forks are going boost width these days.
The frame is longer and slacker, with the all-important boost back endBird
So what else is new with the Zero AM?
It’s not difficult to guess this either, it’s where most bikes are going anyway — longer and slacker.
The front end reach has increased by an impressive 23mm in size large (453mm up to 476mm) to bring it in line with Bird’s progressively shaped Aeris 145 and AM9 enduro bikes.
The head angle has slackened to 64.5 degrees, from 65.4 on the previous generation bike, with an un-sagged 150mm fork, while the seat angle remains at 74 degrees.
While the original bike was designed for 150mm forks, the AM Boost will now also come with a 160mm option, pushing the head angle out to an even slacker 64.1 degrees.
External cable routing and a threaded BB are a mechanic’s best friendBird
What else do you need to know?
The AM Boost still has short chainstays; 420mm in the Medium and Medium Long, while the Large and XL come with 425mm stays, which gives better fore-aft geometry balance with the longer front end.
You can plug 27.5 x 2.8″ rubber in the back, and there’s ISCG05 chainguide mounts present. External cable routing and standard threaded 73mm bottom bracket shells will make your mechanic happy too.
Neat detailing on the chainstay yokeBird
Buying a Bird
One of the things we’ve always liked about Bird is its sales model. You buy direct from Bird, which helps keep prices incredibly competitive, but you also get the opportunity to swap components around at the point of purchase. Got a bit extra cash but want to upgrade from Yari to Lyrik? No worries. Don’t like the Maxxis Minion? Sling a Shorty on instead.
Bird’s Zero AM Boost bikes will start from £1,374 with a RockShox Revelation RC fork, DT Swiss M1900 wheels, SRAM NX11 gears, Level T brakes, RaceFace and Fabric finishing kit, and tubeless out-of-the-box Maxxis tyres.