The Bird Aeris 9, now in its 6th generation, is developed around 29in wheels and is focused quite on enduro riding and racing.
In this latest version, the Aeris 9 provides not simply geometry change, however the opportunity to increase the rear-wheel travel from 160mm to 180mm utilizing a various link, which Bird offers as an optional additional (£90).
As we’ve concerned get out of the British brand name, Bird has actually done a fantastic job of matching the Aeris 9’s modern geometry with flight attributes that’ll help you pilot it down almost any path.
It’s outstanding then, that the Bird Aeris 9 expenses just it does, making it a genuine deal along with a competitor for our 2023 Enduro Bike of the Year title.
Bird Aeris 9 Shimano 12-speed frame and suspension information
Bird offers straight to the customer, providing customisable specifications and loads of thorough info for those who need to know whatever there is to understand about the bike they’re about to acquire.
Alongside the blew up assembly illustrations of the aluminium Aeris 9, you get to see the utilize and anti-squat curves, along with all the normal geometry info. It’s all extremely intriguing things if you like to geek out on truths and figures.
When it concerns frame information, Bird is extremely rider focused. That indicates there’s a concentrate on frame durability and the brand name has actually done its finest when it concerns making life for the home mechanic that bit much easier.
The primary pivot now turns on bigger pivot bearings, which get a double-lip oil/dirt seal to attempt and help protect efficiency for as long as possible.
Then there’s the cable television routing. Bird provides you the choice to path the Aeris 9 internally or externally, depending upon your choice.
Naturally, with the Aeris 9 being developed as an enduro race bike, routing the cable televisions externally produces quicker parts swaps ought to you require to do so. It’s a great touch.
And there’s no routing through the headset due to the fact that individuals at Bird, in their own words, “don’t hate you”.
The rear triangle will fit a decently sized 29×2.6in tire easily, and using the SRAM Universal Derailleur Hanger indicates discovering an extra ought to be quite simple.
While the Aeris 9 features 160mm of rear wheel travel as basic, Bird does offer an extra machined linkage for £90 that will bump it approximately 180mm. This will match the optimum fork travel in advance, which is now likewise 180mm.
That travel is provided through a four-bar linkage and managed by the horizontally installed shock, which nestles under the leading tube.
Bird says it has actually opted for 30 percent development throughout the whole travel variety in a quote to make sure there’s a good quantity of assistance throughout. That indicates it’ll deal with an air or coil-sprung shock.
The anti-squat (the procedure of just how much the suspension withstands bobbing as you pedal the bike) sits at around 100 percent when the bike is drooped to simply under 30 percent of the rear-wheel travel.
Bird Aeris 9 Shimano 12-speed geometry information
Bird provides the Aeris 9 in 4 frames sizes, consisting of medium, medium/long, big and extra-large.
There’s a flip chip on the chainstay, which allows you to modify the rear centre by 6mm, while likewise slowing the head angle by 0.5 degrees and decreasing the bottom bracket by a declared 7mm.
In the much shorter chainstay setting, the rear centre (AKA the efficient chainstay length) is 440mm.
I determined my medium frame to have a reach of 455mm, a slack head angle of 63.5 degrees and a prolonged front centre of 810mm, which ought to produce an extremely steady flight at greater speeds.
As the frame sizes grow, the Aeris 9’s seat tube angle steepens. In the case of my medium frame, I determined it to be a smidge under the declared 77-degrees. The high seat tube angle ought to help to develop a comfy, effective seated position on the climbs up.
I determined the bottom bracket to sit 345mm off the flooring in the much shorter chainstay setting – this is quite in line with the other bikes in the Enduro Bike of the Year test, though remember this can be decreased even more with the geometry change available.
Bird Aeris 9 Shimano 12-speed spec
In similar method as Cotic, which likewise offers direct to the customer, Bird provides the Aeris 9 with a structure Shimano or SRAM 12-speed build.
You can then set about personalizing every part to fit your choice or spending plan, picking from a variety of brand name alternatives. You can even include an O-Chain gadget, FidLock water bottle, extra derailleur wall mount or the longer-travel, 180mm link.
My Aeris 9 is developed around a Shimano XT drivetrain with a Race Face crankset.
Up front, a RockShox ZEB Ultimate fork with 180mm of travel. The ZEB Ultimate utilizes the latest DebonAir+ air spring and extremely adjustable Charger 3 damper.
The RockShox Super Deluxe Ultimate rear shock is likewise upgraded for 2023 and provides low- and high-speed compression and rebound-damping change.
Formula Cura 4 brakes bring the Aeris 9 to a stop, while DT Swiss supplies its FR541 rims developed onto Hope Pro 4 centers. I’d have chosen to have actually had 203mm rotors at the front and back to increase brake power.
These are covered in Maxxis tires. At the front, there’s an Assegai in the 3C MaxxTerra substance and EXO+ case. At the back, we get a Minion DHR II, in the very same substance and case.
Bird provided the bike with the stiff Race Face Next R handlebars and slim Race Face Getta Grips, which I discovered too slim and unforgiving. Bird gladly switched these out for some softer DMR Deathgrips, which assisted enhance convenience on rougher routes.
Bird Aeris 9 Shimano 12-speed flight impressions
I rode the Bird Aeris 9 on a variety of routes around southern England and Wales.
These differed in surface type, speed and gradient, consisting of some manufactured tracks cluttered with high-speed rock gardens, heavy effects and huge dives. There were likewise steeper, natural, technical routes where the roots and rocks abounded however speeds a bit lower, together with whatever in between.
Bird Aeris 9 Shimano 12-speed setup
As Bird enjoyed to provide the extra link, I had the ability to test the Aeris 9 with 160mm and 180mm of rear-wheel travel. I chose the latter general, generally due to the fact that I felt the bike was at its most well balanced.
In this setup, I seemed like the much shorter 440mm chainstay setting worked finest for me.
With both travel setups, I ran 30 percent droop and no volume spacers in the shock. I opened the low-speed compression and rebound damping dials completely, though left the high-speed compression in the center position.
With the fork, I opened the high- and low-speed compression and rebound damping completely and had 54psi in the air spring to get the ZEB Ultimate to operate in a method I enjoyed with at 68kg (completely kitted up).
Aside from changing the shock pressure somewhat when changing in between links, I didn’t require to modify any other modifications throughout screening.
Bird Aeris 9 Shimano 12-speed climbing up efficiency
The high seat angle, paired with the 600mm efficient leading tube, puts you in a fantastic position when seated to deal with the climbs up.
In truth, the Bird regularly satisfied me when pointed uphill, thanks in part to that position, however likewise due to how well the bike pedals. There’s a little suspension bob as you turn the pedals however inadequate to ever necessitate grabbing the limit lever on the shock to company it up.
Instead, you can easily leave it open, permitting it to work away below you as you inch your method up the hill.
On steeper slopes, thanks to the reasonably upright position on the bike and having the front wheel tossed out up until now in front, I never ever fought with wheel lifting as I browsed uncomfortable, slow-speed areas.
Overall, the Aeris 9 definitely climbs up well for a bike with this much travel.
Bird Aeris 9 Shimano 12-speed coming down efficiency
While I was constantly happy with the Bird’s percentages when seated and climbing up, I was even better when up out of the saddle and getting penetrated technical, high singletrack. There, the Aeris 9 really comes to life.
It’s not up until you come across something a little dicey or stressful that you understand simply how well balanced the Aeris 9 feels.
When dealing with high, succeeding turns that culminate in a high-load catch berm (that’s actually more of a narrow rut that needs to be struck to remain on the path), I felt my self-confidence begin to approach.
The Aeris feels so well balanced and well-centred that on every run I felt I might release the brakes that bit earlier and struck the area quicker and quicker.
Both the front and back of the bike provided ample assistance to actually let me press the bike into turns like this, preserving the bike’s vibrant geometry and never ever providing suspension travel up too quickly at the same time.
This all corresponds to bring more speed as you barrel out of the exit of a turn banked over on the edges of the remarkably foreseeable Maxxis tires.
Suitably delicate
On routes that aren’t rather as high, the Aeris 9 handles to preserve momentum quite well.
The back end of the bike is appropriately delicate and tracks the path’s shapes well, which in turn assists to keep the tires grasping.
It doesn’t feel as active or as luxurious as the very best on test. That’s not always a bad thing, however, however it indicates things don’t feel as vibrant or as responsive in some circumstances.
While that more soft sensation through the back of the bike assists to settle feedback through the frame, it can imply some more sedate surface can feel a little duller and less amazing to ride.
Happy at high speeds
On high-speed routes, the Aeris feels simply as at home as it does when browsing high, technical natural surface.
The ZEB Ultimate fork’s Charger 3 damper feels more damped than the older Charger 2.1, while the upgraded air spring feels much better supported. As an outcome, the front of the bike feels calmer and more made up in circumstances that might have had the old fork pitching and diving more routinely.
That assists to sync the front with the rear end, which likewise feels extremely managed.
Coupled with the stretched-out geometry, the outcome is masses of stability at high speeds.
Andy Lloyd / Our Media
Through actually rough areas, it’s a reasonably comfy flight, though the stiff Race Face bar does transfer more vibration to the hands than other, flexier alternatives. This is, nevertheless, something you can modify at the point of purchase.
The frame feels perfectly forgiving in extreme surface – it’s not as tight or direct as others, however stays precise and holds a line with ease through challenging areas of path.
Ridden back to back with the very best bikes in the Enduro Bike of the Year test, however, the Aeris 9 doesn’t feel rather as flexible or comfy as some.
I’d state the distinction is reasonably little, however it was definitely something I understood at the end of longer, rougher runs when riding the bikes back-to-back.
How does the Bird Aeris 9 Shimano 12-speed compare?
Compared to the Strive CFR Underdog – another bike with 29in wheels – the Bird masters much of the very same locations, feeling a bit more rounded in some situations.
I’d argue the Strive is the exceptional of the 2 when it concerns how positive it feels on steeper or faster routes. It’s likewise more comfy on rougher tracks.
While the Bird likewise mutes feedback to the rider, I’d state it’s normally more enjoyable and vibrant to ride on mellower routes, where the Strive takes more effort to preserve speed.
The Aeris 9, on the other hand, keeps that speed with less effort and doesn’t feel rather as glued to the path, which enhances its nimbleness in contrast.
Bird Aeris 9 Shimano 12-speed bottom line
Overall, the Aeris 9 is a fantastic bike that provides masses of stability and security when you require it most. However, it can sometimes do not have a few of the enjoyable aspect that the very best bikes in this classification deal.
The easy-to-customise develops make a great deal of sense if you’re keen on spending more in particular locations than others, too. This makes the Aeris 9 a good option if you’re particular about your parts.
That worth, paired with the outstanding flight qualifications, makes the Aeris 9 a seriously outstanding enduro maker and one worth taking a look at if you value self-confidence in challenging surface.
Enduro Bike of the Year | How we evaluated
Just what makes up a fantastic enduro bike and what does it require to make the crown of the very best enduro bike on test?
We’d argue it’s everything about balance and compromise.
Enduro riding and racing takes in all type of surface and gradients. To tackle it with confidence, securely and at speed, your bike requires to feel well balanced, made up and steady.
Essentially, that corresponds to suspension that keeps the tires glued to the path however avoids the bike sensation like a bucking bronco when things get rough.
Of course, balance doesn’t simply originate from the suspension, however the geometry, too. The ideal mix needs to allow it to seem like to a downhill bike when gravity is on its side and pedal back up the hill when the time comes.
The parts package requires to provide good worth for money too. There’s constantly going to be a component of compromise, however the wise brand names will spend their budget plans carefully.
Over a 12-week duration, all of the bikes in this classification were executed their rates on a variety of routes and tracks to determine their strengths and weak points.
The bikes were ridden back-to-back, along with in differing orders to see how every one felt at the start and end of the day, when rider tiredness had actually embeded in.
Our 2023 Enduro Bike of the Year competitors are:
Thanks to…
Thanks to our sponsors Crankbrothers, MET helmets, Bluegrass Protection, Supernatural Dolceacqua and BikePark Wales for their assistance of Bike of the Year.
