Great all-rounder, road or road-to-trail running shoes with a seriously low manufacturing carbon footprint for eco-conscious runners.
Half the carbon footprint of the average running shoe
Eco-friendly manufacturing processes
Sustainable products used
Firm, responsive midsole
Toe box feels roomy
Easy on and off with sock-style opening
Futuristic-looking angular heel at the sole
Wide range of colors
Fun multicolor option with designer Zipeng Zhu
Firm rather than bouncy cushioning
On the heavy side
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Allbirds Tree Flyer 2: first impressions
Reducing carbon emissions and funding high impact carbon offsetting projects is very important to Allbirds in their commitment to sustainability. The updated version of their Tree Flyer road running shoe (we believe you could also consider it a road to trail running shoe) only produces 7.21kg CO2e (carbon dioxide emissions) during manufacture, while the average running shoe is responsible for pumping out 14kg.
• List price: £150 (UK) / $160 (USA)
• Weight (pair UK 6.5): 560g / 19.8oz
• Colors: White / Gray / Black / Sky Blue / Multicolor / Tan / Dark Blue / Pink
• Drop: 8.5mm
• Compatibility: Designed for short, fast-tempo trail runs up to 10k but can do ultras (we think!), daily walking, gym and fitness classes
This is brilliant and completely the way the world should be turning, but how does it fare at its other job – being a running shoe?
First off, it’s very comfy straight from the box, with a one-piece knitted mesh upper (made from FSC-certified TENCEL Lyocell, eucalyptus tree fiber) that’s more breathable and stretchier across the toes than the arch area to ensure a secure fit, along with the recycled plastic bottle shoe laces. Bio TPU (made from renewably-sourced materials, such as wood chips and rice husk) overlays protect the toes and add support, stability and durability to the side of the shoe. The ZQ (high animal welfare and environmental standards) merino wool-padded ankle cuff is supremely comfy on the inside, and supported on the outside with recycled materials from the midsole foaming process.
The firm midsole performs well especially on shorter, faster runs (it’s designed with 10k in mind) and is made from Allbirds’ SwiftFoam which is made from bio-based Pebax (beans from the eco-friendly, carbon-sequestering castor plant). The grip from the FSC-certified natural rubber is excellent on roads and it will even handle some gritty, slightly muddy trail running paths too.
Allbirds Tree Flyer 2: on the trails
The recycled and sustainable components and manufacturing processes of this shoe make me feel much more planet-friendly when I run in the Allbirds Tree Flyer 2, the joy of which naturally makes me run faster (not scientifically proven!). I would like to try a half size smaller as they come up roomy, and also slightly heavier than average at 560g / 19.8oz per pair, which makes sense if the sizing is a little large.
The cushioning and grip make this shoe a great all-rounder – there’s enough padding for comfort both on roads but also the rocky paths of the Leicestershire countryside, and even enough ground feel for easy trail running.
The Allbirds Tree Flyer 2 is designed with a responsive, quick tempo 10k (6 miles) in mind, but as a committed ultra plodder I took these for a 16k (10 mile) spin around the Tarmac road, gravel paths and grassy, rocky hills of Bradgate Park. I couldn’t really see any reason why this shoe can’t also perform perfectly well as an longer-distance running shoe for those who like a firm and responsive – rather than a super-cushioned and bouncy – feel.
I have posted this pair to one of The Green Runners to see how the Allbirds Tree Flyer 2s fare for durability – another important aspect of sustainability – and will update this review next year. Check back!
The co-founder and former editor of Trail Running magazine, Claire now runs the YouTube channel Wild Ginger Running, creating films packed with trail- and ultra-running content. An award-winning journalist, writing for outdoor and adventure sports magazines and websites, her first book The Ultimate Guide to Trail Running 5k to 50k is out in January 2021. Claire also speaks and presents at events and races.