You can take it all with you

Kiyoshi Iwai is a self-proclaimed “passionate environmentalist and surfer” who moved from Japan to California two decades ago. After watching the traffic congestion grow worse every year, he decided that cargo bikes could be part of the solution.

He founded Cero Bikes in 2015 with the idea to build a compact electric cargo bike inspired by such bikes as the Japanese Mamachari, the British Royal Mail Bike and the Schwinn Cycle Truck. He worked with design, branding and engineering professionals at Vapor Studio and GSD Global. They tested prototypes and launched the bike via a crowdfunding effort, which ended up funding their initial order. The bike was well-received, including by us here at EBA as we reviewed it in 2018.

In the years since, the bike has been updated with several really smart changes. For starters, the moto spec has been upgraded from the original Shimano E6000 to the E6100, which allowed Cero to switch to a Gates carbon belt drive and a Shimano Inter-5 Nexus internally geared hub built specifically to go with that motor.

“This is a premium, high-quality e-cargo bike with superb fit and finish that rides well and can be expected to last many years with very little maintenance. This is a bike that could easily replace a car for a family.” 

Also news was gaining an EN 15194 certification, a cryptic name for a European Union certification that required several modifications that Cero claims makes the new model one of the safest bikes available. This certification allows Cero One to distribute across EU borders and in the U.S., but most e-bike retailers cannot sell the same bike in the EU and the U.S. The only difference is the top speed is set to 20 mph in the U.S. and 15.5 mph in the EU.


The single-size Cero One starts with an aluminum frame with a low-step-through design and with a stand-over height of only 20.4 inches. The 20-inch front wheel ensures that the basket attached to the head tube can sit lower for better balance and handling. The small front wheel makes it very responsive and maneuverable. In back you’ll find a 26-inch rear wheel. There’s an integrated cafe lock, as well as a center stand to keep the bike stable while loading cargo.


The rear rack is bolted on and has all the attachment points for panniers, compatible child seats, or anything you might want to strap or bungee to it. For the front, you have the choice of two different-sized baskets or a simple flat rack. The rack is bolted to the head tube. Front and rear fenders are included.

The dual-piston hydraulic brakes provide plenty of stopping power, even when the bike is loaded. Note those black breakaway fender struts. That’s part of their European regulations, even passing back to the American edition.

The seatpost can be adjusted for height, as can the stem, which can be raised or lowered 2.8 inches, and articulated up front as well for an even more upright position. Cable routing is partially internal in this new version. A twist of the Shimano grip shifter offers you five internal gears from the Inter-5 Nexus hub. 

Touch points include Ergon grips and saddle, as well as flat, plastic pedals covered in grip tape to make them compatible with any type of shoe, even flip-flops.


Cero went with a full list of Shimano components on this iteration of the One, including the STEPS E6100 motor. They’ve shaved the weight down to 6.3 pounds, narrowed the Q-factor, and they claim it uses 20 percent less energy than its predecessor. 

Note the included bell, which is pleasantly loud, twist-grip shifter, and nice Ergon lock-on grips.

They use a standard Shimano 504Wh external battery mounted on the downtube. That design hasn’t changed a bit in several years. We’d wonder about the idea of spec’ing the bike with a higher-capacity battery, but most cargo bike riders are neither looking for that added range, but they are the type of riders who are more likely to carry multiple batteries. 

The E6100 LCD display is easy to read in any lighting condition and can be used with Shimano’s E-Tube app to customize power levels and perform diagnostics. The whole system is weather-resistant, so if you get caught in the rain or ride through some puddles, you don’t need to worry.


The One is a versatile bike that would work well for commuters, even those who need to carry a lot of stuff for work. The bike is rated to handle up to 300 pounds of rider, plus cargo, including up to 70 pounds total cargo and a 55-pound limit on any one rack. It’s certainly a good bike for taking your kid out for a ride. This is also a truly good grocery-getter bike. 


As with any Shimano-powered e-bike, when you start it up, you have to ensure you don’t move the bike or touch the pedals while it zeros out the torque sensor. We were greeted with the dreaded “W13 error” more than once. Shimano still hasn’t fixed this, even in their new motors. This drives us nuts.

The Shimano monochrome display is very easy to read in full sunlight or at night.

Once the bike is on, however, the power kicks in nicely. The motor has a slight whine that some liken to a quiet sewing machine. That’s the only sound you’ll hear over the tires, as the belt drive is so quiet. Shifting with the Nexus hub is faster than a chain/derailleur/cassette—absolutely instantaneous. It’s pretty quiet most of the time, except on steep hill climbs when you’d hear a “ping” when the hub shifts under load.

Pedaling can be as near effortless or full of effort as you want. There’s no throttle, and though it has a cadence sensor, the torque sensor trumps that, so if you put in no effort other than spinning the pedals, you won’t keep your momentum.

Spanninga lighting front and rear makes sure you can see and be seen.

Steering response from the small front wheel is quite snappy, and if you aren’t used to having a basket affixed to the front of your bike, it will seem odd at first that you turn the bars to turn, but the basket always stays straight ahead. That feeling wears off after a while.

The handlebar has a really pleasant sweep to it, and the Ergon ergonomic grips make even long rides very comfortable. The bike is very comfortable on either short or long ones, and when we loaded up it still rode well. 

The bike feels planted, even when cornering underweight, thanks to the matched Big Ben Plus tires. You can run 35–55 psi, and even at 55 psi with plenty of cargo, the high volume of the 2.15-inch tires took up bumps to keep them from transferring to the rider too harshly. There’s not much rain in SoCal this time of the year, but when going to and from various farmers’ markets, there’s always water on the road. The full fenders did their job perfectly in keeping our pants and our produce dry.

The center stand is a nice feature for holding the bike steady and level while you load up the racks.

The big basket is such a nice feature on this bike. It’s well worth the extra $100, especially when paired with the mesh insert with a built-in pocket. We’d also recommend springing the extra $50 for the keyed-alike ABUS chain lock to go with the ABUS cafe lock. When you’re walking around a market or running into a store, that’s extra peace of mind and one less key to carry around.

The rear rack can handle a Yepp seat for kids, panniers or whatever you may want to strap to it.

The design makes sense especially if you ever have to carry it up or down stairs (as we did), because you can grab the back of the bike either by the seat tube or by the gusset near the bottom bracket, which actually doubles as a handle. 

The Bates belt drive and Shimano Nexus internal-shifting rear hub offer a clean, very low-maintenance drivetrain.


At $3799, a price that’s a few hundred more than the last time we tested it, it’s not an inexpensive cargo bike. It is instead a premium, high-quality e-cargo bike with superb fit and finish that rides well and can be expected to last many years with very little maintenance. You won’t find a car like that, and this bike could easily replace a car for a family. We think it’s a good value at the price.



Price: $3799

Frame: 6061-T6 aluminum

Fork: 6061-T6 aluminum

Motor: Shimano STEPS E6100

Battery: Shimano E8010, 504Wh

Controls: Shimano STEPS

Charge time: 3-4 hours

Top speed: 20 mph (Class 1)

Range: Up to 105 miles (claimed)

Rear hub: Shimano Nexus Inter-5E

Chain: Gates Carbon belt

Brakes: Shimano hydraulic disc

Saddle: Ergon SFC30-S gel

Rims: Alex double wall, 20”x35.5mm front, 26”x
35.5mm rear

Hubs: Shimano 

Tires: Schwalbe Big Ben Plus, 20×2.15” front, 26×2.15 rear

Weight: 58.2 pounds

Color choices: Halu Blue or
Shio Grey

Sizes: One size