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Bird Aether 9 AL specification and geometry

Posted by Matt | January 7, 2022 | 1 comment so far

Bought in February 2021 but not out on the trails until March, this is the specification and geometry of my Bird Aether 9 full suspension mountain bike.

This bike has turned out to be a great purchase, which deserves review of its own. There are a couple of areas of the specification I might tweak but nothing – apart from deeper pockets – that stops it being an absolute pleasure to ride right out of the box.

If you want a Bird Aether 9 of your own, find it on the Bird Bikes website.

Bird Aether 9 AL specification

Colour	Tungsten Grey
Frame	Aether 9 6066-T6 aluminium frame 130mm travel, 12x148mm bolt thru rear axle, clearance for 29×2.6 tyres, ISCG05 chainguide mount, full continuous external cable routing
Fork	RockShox Pike RCT3 140mm travel, 51mm offset, 29″, 15x110mm Boost, Thru axle, DebonAir air spring, Charger 2 damper cartridge, Low-speed compression adjustment to firm, Tapered steerer
Rear shock	Rock Shox Deluxe Select + RT Debonair 210x55mm
Shifter	Shimano Deore M6100 12 speed
Rear derailleur	Shimano Deore M6100 12 speed, long cage
Cassette	Shimano Deore M6100 12 speed, 10-51
Chain	Shimano Deore M6100
Chainset	Shimano Deore M6100 170mm, 32T chainring, 52mm chainline
Bottom Bracket	Shimano Deore M6100 BSA, 73mm
Brakes	Shimano SLX M675 2 piston, tooled reach adjust, steel-backed organic pad
Discs	Hope Technology floating disc FW: 203mm, RW: 180mm
Headset	Bird ZS44;28.6 \| ZS56;40 Black
Stem	Nukeproof Horizon 50mm, 35mm clamp, Purple
Handlebar	Race Face Next 35 Carbon 760mm, 20mm rise, 8° backsweep, 35mm clamp
Grips	Ergon GA3 in Purple
Seatpost	Bird Down Dropper V2.1 150mm, 31.6 internal
Seat clamp	Nukeproof Horizon 34.8mm, Purple
Saddle	SDG Bel Air 3 Lux-alloy rails, 260mm x 140mm
Rims	Hunt Trail Wide 29″, 32H, 30mm internal, tubeless ready
Hubs	Hunt FW: 15x110mm Thru Axle, RW: 12x148mm Thru Axle
Tyres	Maxxis FW: Minion DHF Maxx-Terra 3C WT 29×2.5, RW: Ardent 29×2.4

Bird Aether 9 geometry chart (with 140mm fork)

Sizes	M	ML	L	XL
Effective Toptube	Size M605 mm	Size ML630 mm	Size L655 mm	Size XL680 mm
Reach	Size M461 mm	Size ML484 mm	Size L507 mm	Size XL528 mm
Stack	Size M625 mm	Size ML634 mm	Size L643 mm	Size XL652 mm
Seattube	Size M395 mm	Size ML420 mm	Size L445 mm	Size XL470 mm
Chainstay	Size M430 mm	Size ML430 mm	Size L430 mm	Size XL430 mm
Head Angle static / sagged	Size M65 / 64.8°	Size ML65 / 64.8°	Size L65 / 64.8°	Size XL65 / 64.8°
Seat Angle	Size M77°	Size ML77°	Size L77°	Size XL77°
BB Drop static / sagged	Size M40 / 81 mm	Size ML40 / 81 mm	Size L40 / 81 mm	Size XL40 / 81 mm
BB Height static / sagged	Size M330 / 289 mm	Size ML330 / 289 mm	Size L330 / 289 mm	Size XL330 / 289 mm
Wheelbase	Size M1208 mm	Size ML1235 mm	Size L1262 mm	Size XL1289 mm
Headtube	Size M110 mm	Size ML120 mm	Size L130 mm	Size XL140 mm
Axle to Crown	Size M551 mm	Size ML551 mm	Size L551 mm	Size XL551 mm
Fork offset	Size M42 mm	Size ML42 mm	Size L42 mm	Size XL42 mm

Filed under Bikes in January 2022

About the author

Matt is one of the founding Molefathers of the Muddymoles, and is the designer and main administrator of the website.

Having ridden a 2007 Orange Five for many years then a 2016 YT Industries Jeffsy 29er, he now rocks a Bird Aether 9 and a Pace RC-627.

An early On-One Inbred still lurks in the back of the stable as a reminder of how things have moved on. You can even find him on road bikes - currently a 2019 Cannondale Topstone 105 SE, a much-used 2011 Specialized Secteur and very niche belt drive Trek District 1.

If you've ever wondered how we got into mountain biking and how the MuddyMoles started, well wonder no more.