Aeris AM9 | Bird MTB // Born in Swinley, Built in the UK. (2025)

A sublime riding, pocket friendly trail and enduro slayer… 4.5/5* – Read the full review

Bikeradar

The Aeris AM9 is the enduro bike you have been waiting for. Be prepared toconquer the roughest trails and smash your personal bests.

This is the bike that changed my mind about 29 inch wheels! Quite simply the fastest bike available for fast, steep and rough enduro courses.

Ben, Founder

The new Aeris AM9 features:

• 29 Inch Wheels
• 150mm front and rear travel
• 6066 tube-set, designed to give the best stiffness to weight ratio
• 2.5″ tyre clearance
• Self locking mini-collet axle system
• One piece hollow section yoke
• 148 Boost rear end for maximum tyre clearance and stiffness
• One piece brake/axle assembly for maximum precision and minimum squeal
• Metric shock sizing
• 1x specific rear end for maximum stiffness
• ISCG05 mount
• Bottle cage mounts
• SRAM Maxle rear axle
• Fantastic pedalling performance combined with a progressive shock curve
• External cable routing, because we live in the UK
• Threaded bottom bracket
• Tapered ZS44/ZS56 headset
• Reverb stealth routing
• Max complement sealed cartridge bearings on all pivots
• A stonkingly good price
• 4 sizes, 3 colours and complete configuration control on all models

Geometry

We take pride in our in house developed frame geometry. Our bikes are long and roomy without feeling stretched out. When you ride a Bird your body weight is perfectly distributed between the wheel axles, resulting in supreme stability and confidence. Our long front ends keep the front wheel planted to the ground on steep climbs while giving you extra breathing room. Nice.

A word on chainstay lengths; some like it short, some like it long. We like it balanced. While super short chainstays can make a bike feel playful and easy to wheelie, they also shift your weight towards the rear axle, meaning you have to work harder to load up the front wheel during corners. Really long chainstays provide stabilty at speed but also suck a lot of the fun out of riding and can make a bike handle like an oil tanker. The Aeris AM9, like the 145, strikes a balance between stabilty at speed and sharp handling in the tight and twisties.

Our bikes are class leading when it comes to downhill performance. Slack head angle, low bottom bracket and sensational rear suspension. Yes, the Aeris AM9 is an “enduro” bike through and through. What does “enduro” mean though? Modern enduro racing is a multi stage race where the riders are timed on the fun parts. If you like to crank up a hill and then blast down again as fast as possible then I think that we’ll get along just fine.