​​Allbirds Launches The Tree Flyer, It’s Most Performance-Focused Running Shoe Ever

Allbirds Tree Flyer running shoe
(Image credit: Nick Harris-Fry / Future)

All things being equal, most runners would be more than happy to opt for sustainable shoes over ones that use synthetic petroleum-based materials. The trouble is that the performance drop-off from the best running shoes to sustainable shoes is too steep for many runners to accept.

The Allbirds Tree Flyer aims to change that. It’s a lighter, more performance-focused shoe than the brand’s previous running option, the Tree Dasher 2.

A range of natural materials are used in the Tree Flyer. The knit upper is made from a eucalyptus-based tree fibre and the outsole uses natural rubber. The SwiftFoam midsole is made from castor beans and not only requires less energy to produce than the Sweetfoam used in the Tree Dasher, but is also lighter and more responsive.

Allbirds Tree Flyer running shoe sole

(Image credit: Nick Harris-Fry / Future)

The Tree Flyer has a carbon footprint of 9.92kg CO2e, which again is an improvement on the Tree Dasher 2 with its footprint of 10.7kg. It all hopefully adds up to a better running shoe that’s even easier on the environment.

You’ll pay a premium for the improvements, though. The Tree Flyer costs £150, a £25 increase from the Tree Dasher 2. It’s a steep price, but one many runners may be willing to pay for the more environmentally friendly design, if the performance is there.

Unfortunately, in my early testing the Tree Flyer struggled to match up to the standards of normal running shoes. It is a little lighter than the Tree Dasher, weighing 287g compared with 298g for a UK 8.5, but the ride is similar. Both feel quite heavy, firm and awkward on the foot. 

The upper is also a little loose and if I ran in anything above an easy pace my foot moved around in the shoe, which resulted in some irritation from the knitted material rubbing.

Like the Tree Dasher 2, the Tree Flyer works well as a stylish shoe that you can also use for a few easy, short runs each week, but given the focus Allbirds has placed on performance, it underwhelmed. You can pick up superior daily trainers like the Puma Velocity Nitro 2, Reebok Floatride Energy 4 or Nike Pegasus 39 for much less than £150, and all three of those are more comfortable and versatile to use for a range of different runs. 

Of course those shoes don’t have the green credentials of the Tree Flyer, but if you are all in on an environmentally-friendly design the Tree Dasher 2 is better value given that there isn’t a huge step up in performance with the Tree Flyer.

Allbirds deserves credit for continuing to develop shoes that are less harmful to the environment and aiming to create options that runners can use without sacrificing on performance, but with the Tree Flyer there is still a trade-off to be made. We hope sustainable shoes will continue to improve while big brands make their popular lines more environmentally friendly – but right now, if you’re all about performance, it’s still hard to go green.

Buy from Allbirds | £150

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Nick Harris-Fry
Senior writer

Nick Harris-Fry is a journalist who has been covering health and fitness since 2015. Nick is an avid runner, covering 70-110km a week, which gives him ample opportunity to test a wide range of running shoes and running gear. He is also the chief tester for fitness trackers and running watches, treadmills and exercise bikes, and workout headphones.