Weight: 301g (M), 237g (W)
Heel-to-toe drop: 8.5mm
Type: Neutral/road
The shoe
When San Francisco-based company Allbirds launched in 2016, it did so with the mission of using natural materials to create the ‘world’s most comfortable shoes’. Appealing to the environmentally conscious consumer, it was also the first footwear brand to carbon label its products.
The Tree Flyer 2 is the second iteration of the brand’s dedicated running shoe, designed for both ‘beginners and experienced runners alike’. Boasting a carbon footprint of 7.21 kg CO2e (which Allbirds offsets to zero), it features a natural rubber outsole with lugs, Allbirds’ SwiftFoam midsole (a bio-Pebax made from castor beans) and a knit upper made from eucalyptus tree fibre, overlaid with bio-based TPU skins for extra support. The aim has been to create a running shoe that’s planet friendly, but that doesn’t compromise on performance.
What everyone's reading
So, can you really have it all?
How is the Tree Flyer 2 different from the original Tree Flyer?
Allbirds has made a number of updates to the Tree Flyer since its original launch last year. New features include a refreshed lug design which functions like teeth on the road to improve traction, overlays on the toe and midfoot for lateral security, increased durability and element protection, and an external heel counter for back-end support.
There’s also been a very modest increase in the amount of Allbirds’ Swiftfoam in the midsole. The original Tree Flyer had a stack height of 30.5mm in the heel and 22mm in the forefoot, whereas the Tree Flyer 2 has a stack height of 31.2mm in the heel and 23.2mm in the forefoot. However, it’s not really enough to notice a difference in the level of cushioning, and the result is just an additional 41g of weight – meaning the Tree Flyer is by no means a lightweight shoe.
What is the Tree Flyer 2 like to run in?
I’ll admit, I didn’t have particularly high expectations for the Tree Flyer 2. I ran in the original and found that, while it had great intentions when it came to its materials and ethos, it didn’t quite meet the mark when it came to performance. So, how does the latest iteration fare?
Well, it’s still an extremely firm ride. This isn’t necessarily a bad thing, especially if you’re running anything up to 10km at a steady pace, but for those longer miles, it lacks that soft, plushy cushioning you can sink your feet into. That being said, I didn’t want to turn home within a kilometre of setting off, which is promising.
You will need to be prepared to do a lot of the work, though. Again, this isn’t always a negative (not every shoe needs to be max-cushioned with a carbon plate, after all), however, towards the end of a 10-mile easy run, it started to feel pretty flat and I wished I was wearing something slightly more responsive.
The thing is, while castor beans are eco-friendly and sustainable, they just don’t have that same level of softness and bounciness that you get with standard Pebax. The bio-Pebax also feels stiff and rigid when you get going, and the Tree Flyer has no rocker geometry to propel you forwards or inject an element of fun into the ride.
On the plus side, I was pleasantly surprised by the shoe’s stability. The TPU overlays on the upper and the cushioned heel counter provide pretty solid lateral and medial stability, which makes the Tree Flyer feel like a running shoe, as opposed to just a lifestyle shoe. The upper, while slightly hot for running in the summer months, provides a solid lockdown and is generally pretty comfortable too.
The outsole is oddly aggressive for a road shoe which, combined with a toe bumper, means the Tree Flyer lends itself to firmly packed trails or gravel paths, despite not being marked as a dedicated trail shoe.
How does the Tree Flyer 2 fit?
The shoe runs true to size and I didn’t experience any cramping or blistering within the toe box. However, I did get some pretty bad blistering on my medial arches, particularly on the right foot, which made the final few miles of a long run pretty laborious.
RW verdict
When it comes to environmental integrity, you can’t fault Allbirds. From the natural materials used throughout the Tree Flyer to its low carbon footprint, it really is one of the most eco-friendly running shoes on the market. It’s also a good-looking shoe, and one you could easily wear day-to-day when you're not running.
It’s just a shame it doesn’t quite hit the mark when it comes to performance. One of our testers described the shoe as ‘not that bad’, but (environmental credentials aside) for £150, do you really want a shoe that’s ‘not that bad’? Personally, there are a number of similarly priced offerings from the likes of Asics, Adidas or Nike that I’d recommend to beginners ahead of the Tree Flyer.
That being said, if you’ve got a strong moral compass and desperately want a more eco-conscious running shoe, you may well opt for the Allbirds Tree Flyer 2. Just keep in mind that you’ll be sacrificing some elements of comfort and performance, and they have a little way to go in terms of offering the kind of shoe that supports every step in style.
