Byar Volta is a shaft-driven e-bike that might never need charging

The 2019 production model of the Byar Volta electric bike.

Photo: Byar Bicycles

Think “bicycle” and most people imagine a handlebar, wheels, and pedals attached to a diamond frame. A chain converts the power generated by leg muscles into mechanical energy to drive the contraption forward. That’s been true for nearly 150 years. A new bike I’ve been testing from a small Dutch startup hopes to change your way of thinking.

The Volta, pictured above, is Byar Bicycle’s first e-bike. Its striking step-through design and floating saddle are the first things you’ll notice. The second is the lack of a chain. That’s because this bike is shaft-driven. Moreover, it features an electric assist provided by an oversized rear hub that cleverly conceals a 250W motor; controller; Bluetooth and GPS radios; sensors to measure torque, slope, and cadence; and a 160Wh battery that can automatically recharge itself.

The Byar Volta is an electric city bike designed for urbanites with a penchant for luxury, not speed. It’s for the two-wheeled casual commuter with a desire to stand out from the crowd and pockets deep enough to absorb its starting price of €3,500, or almost $4,000.

I’ve been testing a Volta prototype for the past few weeks. It was delivered to me by Renier Meuwissen, owner of Byar and the bike’s designer. My ride is a model produced in 2018 for a city-wide ride-sharing venture that never took off. The 2019 Volta that went on sale two months ago in The Netherlands was tweaked to incorporate lessons learned from the 2018 prototype. As such, I can’t offer a full review. I do have some detailed impressions of the prototype I rode that should still apply to the 2019 model.

But first, let’s discuss the merits of shaft drives and all-in-one motors.

Cardan shaft drive.

Image: Byar Bicycles

The Zehus Bike+ all-in-one com

Shaft-driven bicycles have been around for a century, but chains and derailleurs won out due to their ability to translate muscle-power more efficiently through a range of gears. But advances in internal hub gearing systems coupled with the rise of inexpensive electric motors and batteries mostly negates those advantages, especially for riding in flat cities. True, enclosed shaft drives are more complex (and costly) to manufacture, but for owners, the end product is quieter, cleaner, less prone to damage, and requires zero maintenance over the lifetime of the bike.

The ingenious Bike+ rear-mounted motor used by Byar is made by Zehus. The Italian company makes all-in-one motors that power bikes made by dozens of companies, ranging from boutique brands to bicycling giants like Sparta. Zehus motors are attractive to manufacturers looking to electrify their bikes without the hassle of becoming experts in DC power, running wires, developing an app, or compromising their designs with hulking batteries that have to be bolted onto the frame or hidden inside engorged tubes. The concept isn’t new, but Zehus was one of the first, preceding the Copenhagen Wheel by some three years.

Cranking the Volta’s shaft drive feels like pedaling a normal bike — it’s the Zehus Bike+ motor that takes some getting used to. To turn it on, you have to get the bike moving at a walking pace of at least 5 km/h (about 3 mph). Once up to speed, the Bitride companion app will automatically link to the Bike+ motor over Bluetooth. To turn on motor assistance, you have to get up to at least 10 km/h and then pedal backward for three revolutions. This same pedal movement also activates the regenerative braking function to slow the bike down. The longer you backpedal, the more the bike’s speed is converted into energy to recharge the battery. The braking is very gradual. Volta is fitted with hydraulic brakes if you need to stop.

The Bitride app lets you choose between seven different power modes: Turbo, E-bike, Range 1, Range 2, Range 3, Bike+, and Off. Turbo is the full-time pedal-assist mode with a range of up to 35 km. Distance from a single charge extends to a reported 90 km in Range 3 mode. Bike+ holds the promise of never having to charge your battery again. This primarily regenerative mode still provides pedal-assisted power on inclines or at low speeds, but otherwise robs your legs of power on the easier sections of roadway or plunders your speed on downhill slopes in order to keep the battery topped up.

The Bitride app showing a ride up and down a small incline in Bike+ mode. Green means regenerative power is being added back to the battery, red is power delivered to the pedals.

The Bike+ mode sounds taxing but it’s not — not in my limited testing, anyway. Yes, you can feel the extra resistance once you’re up to speed, but it’s trivial, adding maybe 5 percent more load if I had to guess. The Bike+ motor is still intelligent enough to provide an electric pedal assist at low speeds or when climbing an incline as needed. For people riding on mostly flat terrain, I expect you’d rarely have to charge a Volta ridden primarily in Bike+ mode. Nevertheless, Byar says the Volta has a range of up to 160 km depending upon your selected mode.

Turbo mode can quickly overwhelm the bike’s single-speed gear ratio, however. Once I got up to about 22 km/h my feet could barely keep up. Riding at a top speed of about 18 km/h to 20 km/h was the most comfortable. That’s just fine in the congested center of Amsterdam where tourists and traffic present constant danger, but is slow for anyone with a longer commute outside the city center. The Bike+ motor caps out at the European maximum of 25 km/h (16 mph).

Range 1 was my preferred riding mode as it offered the best mix of power assist when needed, as well as power regeneration to help extend the life of the battery.

It’s a lot of choice, frankly, with most of the modes offering only slight variation in power output and regenerative capabilities. But better too many choices than too few. Fortunately, once you’ve identified your favorite mode, you can just set it and forget it. The next time you wake the bike it defaults to your previous riding mode. You can even ride without the app if you prefer — just get up to speed, backpedal three revolutions, and enjoy the pedal-assisted ride.

The aluminum-framed Volta is heavy at 22.5 kg / 50 pounds, but much lighter than my 41 kg / 90 pound prototype fitted with a hulking rear lock and steel basket mounted to the front. Nevertheless, it didn’t ride heavy, feeling very much like a regular Dutch city bike (which are already built like tanks). The weight is offset by the electric motor of course, which kicks in smoothly after about half a revolution from a standing start. 

Some other observations:

• The Bike+ motor turns off automatically after two minutes of inactivity. It will also shut off if the slope sensor detects the bike is horizontal as a safety feature in case of an accident.
• Volta can be remotely disabled by Byar in the event of a theft. The company can also track its location and will do its best to help owners recover their bikes, but makes no guarantees.
• A very useful AXA cable lock is integrated into the frame.
• The front light is wired to a separate front-hub dynamo, not the battery. There’s very little drag created by the dynamo, allowing the front wheel to spin freely when off the ground. The front light is off when standing still and then begins to flicker at low speeds as a safety feature, before glowing steadily when up to speed. The rear light has a small battery that’s charged by the bike to keeps it illuminated even when the bike is stopped.
• Volta ships with a wall charger that charges the bike’s non-removable battery in about three hours. I feel sorry for you if you have to carry Volta up and down any stairs.
• Production Volta bicycles, with more of a back-to-front tilt and bulkier frame, differ slightly from the Volta renders on the Byar website. I prefer the renders.
• Test rides can be arranged upon request.
• The Volta is being sold exclusively in The Netherlands this year in order to keep control of the first production run while maintaining a high level of support. That’s smart.
• Byar hopes to sell 1,000 bikes by 2022, about 300 per year. That level of success would enable it to introduce new designs.

Volta was designed to be the “Rolls Royce of city bikes,” as Meuwissen tells it. As such, you’re not going to be setting any speed records on it. It’s meant for tooling around the city with style and ease.

I think Byar is on to something with the Volta’s marriage of a maintenance-free shaft drive, an all-in-one hub motor, and fresh industrial design. It’s an electric bike that shows a lot of promise, based upon my testing of last year’s prototype. That’s good, because I’d like this company to stick around for awhile; I’ve already seen designs for the next generation of Byar e-bikes, including one showstopper that has more in common with a vintage Bugatti fender than a mechanical horse. It’s a bike that needs to happen.