Bike of the Week

A sustainable folding bike with a lightweight parts spec

This competition is now closed

By Oscar Huckle

Published: September 21, 2022 at 12:00 pm

This week, we have the rather unusual-looking Hummingbird Electric Flax – an electric folding bike with a flax fibre composite frame.

Hummingbird says it's the world's first folding bike frame made entirely of flax plant fibres and, after walking, is the most environmentally friendly form of transport.

Determining the most environmentally friendly form of transport is complicated, but for more information on the topic, why not check out our long read on how green cycling can be?

Now, though, let's take a closer look at our latest Bike of the Week.

Hummingbird has collaborated with Prodrive, best known for its motorsport experience, to develop and engineer the frame.

The flax fibre composite frame is said to match the strength of Hummingbird's carbon fibre models. Hummingbird claims flax also offers improved vibration damping.

Unlike carbon fibre, flax is a sustainable material. The brand says the waste generated at the production stage is biodegradable and is less harmful to dispose of and recycle.

The frame has a gloss lacquer over the flax fibres, which are fully on display.

Hummingbird says the Electric Flax will accommodate riders from 5ft 1in to 6ft 5in and the maximum weight, including baggage, is 110kg.

The rear triangle is made of CNC’d aluminium and the bike features a full carbon fibre fork.

Every fortnight, we’ll bring you a detailed first look at one of the latest bikes (or framesets) to arrive at BikeRadar HQ – from road to commuting, gravel to enduro, and anything in between.

This is our chance to introduce the bike and everything that makes it unique before hitting the road or trails.

Head to our Bike of the Week hub for previous editions.

The Electric Flax retails for £4,995 and is driven by a second-generation Zehus ‘All-in-one’ 250W hub motor and built in-battery. It's said to weigh 3.5kg and will cut out at 15.5mph.

The charger connects to the rear wheel axle and Hummingbird says it will take three hours to charge fully.

Hummingbird says the Zehus system is designed to work with the Bitride app, which enables you to customise the settings, as well as monitor your speed and remaining battery life using Bluetooth 5.1 connectivity.

When you connect to the app, it’ll display your battery life and Hummingbird says it can even help with navigation or locating your bike. When your specific motor is connected to the app, you can also ‘lock’ the bike.

The range is said to be approximately 50km on a single charge, which is an improvement of 20 per cent over the first-generation hub motor.

Hummingbird claims this latest motor also offers a 50 per cent improvement in torque.

Hummingbird says when folded, the bike will measure 116x60x20cm.

To fold the Hummingbird, unlock the swingarm quick-release skewer, located near the top of the seat tube junction and lift the bike slightly to fold the rear wheel under the frame.

The handlebars can be adjusted to a neutral position with a lever at the clamping area and the stem quick-release can then be unlocked.

The bars then fold to the non-driveside and a clip in place of the bar-end on the driveside grip can hook onto the side of the swingarm to keep everything secure.

You can then drop the seatpost and remove the pedals, and the pedals can be slotted into the brake bridge.

The build continues Hummingbird's pursuit of lightweight, with what appear to be custom own-brand parts. This includes the finishing kit and brake levers.

Both the handlebar and seatpost are full carbon, with the handlebars measuring 520mm wide and featuring a 50mm rise.

The seatpost features titanium hardware and is fastened to the frame with a CNC’d quick-release clamp for folding. Sitting atop the seatpost is an unbranded saddle with carbon rails in a 130mm width.

The brake levers seem to be Hummingbird's own and are joined to Tektro R539 rim brake calipers on our build, although the spec sheet lists the calipers as Shimano BR-R451s.

When it comes to the drivetrain, Hummingbird has specced a Shimano Alfine crankset with a 48-tooth chainring and an integrated CNC chainguard. The rear sprocket has 12 teeth and joining them together is a YBN superlight hollow pin chain.

16in Schwalbe Kojak tyres are specced and installed onto an ‘ultralight aluminium alloy’ wheelset, of Hummingbird's own.

All-in, the bike weighs 10.65kg, with the removable Wellgo flat pedals.

We’re currently testing the Hummingbird Electric Flax and we’ll bring you a full review soon.

Technical writer

Oscar Huckle is a technical writer at BikeRadar. He has been an avid cyclist since his teenage years, initially catching the road cycling bug and riding for a local club. He's since been indoctrinated into gravel riding and more recently has taken to the dark art of mountain biking. His favourite rides are epic road or gravel routes, and he has also caught the bikepacking bug hard after completing the King Alfred's Way and West Kernow Way. Oscar has a BA degree in English Literature and Film Studies and has close to a decade of cycling industry experience, initially working in a variety of roles at Evans Cycles before joining Carbon Bike Repair. He is particularly fond of workshop tool exotica and is a proponent of Campagnolo groupsets. Oscar prefers lightweight road and gravel frames with simple tube shapes, rather than the latest trend for aerodynamics and full integration. He is obsessed with keeping up to date with all the latest tech, is fixated with the smallest details and is known for his unique opinions.

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