Allbirds Tree Flyer Review: A Sustainable Daily Trainer with Trade-Offs

Introduction

Allbirds set out to make performance running shoes with a much lower carbon footprint than the petroleum-based models most of us run in. Earlier efforts like the Tree Dasher got the sustainability part right without quite nailing the running experience. The Tree Flyer is the brand’s first shoe aimed squarely at performance running, and Allbirds claims it can run as well as many traditional daily trainers.

That is a big claim, and after putting real miles on this shoe the picture is mixed. There is genuine progress here, particularly in comfort and materials, but the ride still falls short of what dedicated running shoes deliver.

Design and Key Details

The Tree Flyer costs £150 in the UK and $160 in the US. It weighs 269 grams (9.5 ounces), with an 8.5mm drop and a stack height of 30.5mm in the heel and 22mm in the forefoot. Each pair carries a stated carbon footprint of 9.92 kilograms of CO2, printed on the back of the shoe.

The midsole uses a new foam called Swift Foam, made from castor beans, a renewable resource Allbirds says has a 20% lower carbon footprint than petroleum-based alternatives. The brand also claims it is 30% more responsive and 25% lighter than the Sweet Foam used in the Dasher. The upper is a stretchy, densely knitted eucalyptus tree fibre, built in a bootie style that wraps the foot. There is a fairly minimal heel counter with modest padding, and a sturdy exposed external heel counter made from recycled midsole waste. The outsole uses a zonal traction pattern for grip and added durability.

On fit, the sizing story is worth attention. Some testers found the shoe ran true to size but felt loose and baggy around the midfoot and heel, with some irritation on the top of the foot from lateral movement on downhills and corners. Others found their normal size hugely too long in the toe box and went half a size down. The safest advice if you have a narrow foot is to try half a size down, because the knitted upper is roomy and does not lock the foot down as securely as more structured mesh uppers.

Ride and Performance

The ride is where opinions divide most sharply. The Tree Flyer is Allbirds’ softest and most comfortable running shoe yet, and it softens up further after the first few kilometres. It encourages a higher cadence and a forefoot strike, with a relatively direct, minimal feel somewhat reminiscent of a Nike Free, just with a bigger platform.

However, the firmness is a recurring theme. Some runners found the midsole very firm, with a cushioning feel that did little to deaden impact, making runs over 5k feel like hard work without much reward. Others managed easy 10k runs comfortably and would even consider slower long runs up to around 10 miles. The common ground is clear: this is not a race day shoe, and it is not the shoe to pick if you want a plush, protective ride for high mileage.

Over around 20 miles of testing, a mix of paved roads, pavements and compacted riverside paths, the shoe handled easy and steady paces adequately but never quite disappeared on the foot. It feels heavier and clunkier than its weight suggests, and the ride is firm without being genuinely responsive. The upper deserves credit though: it is flexible, breathable, comfortable, and the bootie fit wraps the foot nicely with decent lace lockdown. The knitted fabric does get a little rigid through the midsection of the shoe, which slightly reduces comfort compared with the forefoot.

Who This Shoe Is For

If you run casually, maybe three times a week, mostly covering three to six miles at easy paces, the Tree Flyer makes genuine sense. It is comfortable to wear all day, works fine for short treadmill miles or gym sessions, and it does a real job for the planet. Runners coming from the Tree Dasher will notice more softness and protection, and it shows Allbirds moving closer to its goal of a true performance shoe from sustainable materials.

If you are a serious runner logging 10 to 15k daily and expecting a modern daily trainer experience, this shoe will likely disappoint. It cannot compete on foam with shoes like the Puma Velocity Nitro 2, Nike Pegasus 39, Reebok Floatride Energy 4 or Saucony Ride 15, all of which deliver a more enjoyable ride, often at lower prices.

Things to Consider Before Buying

The sustainability angle is the headline. The Swift Foam and tree fibre upper represent real material innovation, and until these materials are produced at higher volumes, you pay a premium for them. At £150 or $160, the price is steep compared with excellent conventional trainers.

You should also accept the fit caveats: a roomy, somewhat baggy hold around the midfoot and heel, a shoe that is potentially too long in your normal size, and a ride that stays firm and present on the foot. If those compromises bother you, there are better options, but they will not carry a 9.92kg CO2 label.

Buying Advice

The verdict is straightforward. If you weigh the eco credentials heavily and your running is casual, short and easy-paced, the Tree Flyer is worth a look despite the premium price. It offers real cushioning compared with earlier Allbirds models, and the brand deserves credit for pushing sustainable materials closer to performance territory.

If instead you want a dedicated daily trainer to rack up serious mileage, race in, or run anything beyond 5k with genuine performance, look elsewhere. This is ultimately a comfortable, well-made casual shoe and gym shoe that can handle a bit of easy running, not a shoe built for endurance training.

Conclusion

The Allbirds Tree Flyer is a commendable step forward for sustainable running shoes and Allbirds’ best attempt at performance yet, but the firm midsole foam keeps it from competing with modern conventional trainers. Buy it for the planet and for easy, casual miles, not for racing or long-distance performance.