CERO One Review

This review was provided for free using a demo bike and accessories. My goal is to be transparent and unbiased with you, this video and writeup are not meant to be an endorsement of CERO products. I welcome your corrections, additions, and feedback in the comments below, and the CERO electric bike forums.

Observations:

• CERO is based in Los Angeles California, and began in 2015 when the founder Kiyoshi Iwai started researching electric bikes. The name relates to “zero” emissions and sustainability. Model one is their first and only product, which is inspired by the Mamachari bicycles of Japan. They are compact mini-cargo bikes that parents can use for all sorts of tasks. The front and rear baskets provide space for hauling or bringing children along on rides.
• The CERO One is a feature-complete electric bike, meaning it has fenders, integrated lights, and racks. It’s very capable and versatile. This is the second generation of the One, which utilizes a belt drive, internally geared hub, and upgraded motor compared to the first generation. Weight has increased by two pounds, cables are now internally routed, and the price has gone up ~400.

Pros:

• This is really a one-of-a-kind electric bike design for North America. It’s inspired by the very popular Mamachari bicycles of Japan, and it’s done very well. I trust the Shimano brand motor, battery, drivetrain, and brakes very much, having seen them perform well on other ebikes over the years. Apparently, it’s being distributed in Australia, Germany, and Canada after growing in popularity since 2017 (although the naming and branding may be different in these locales).
• Most cargo bikes are long and wide, I love how the CERO One is only ~70 inches long (that’s actually shorter than a traditional bicycle, which are usually ~72″) and the adjustable stem that lets you turn the bar sideways makes it super easy to store in narrower spaces.
• It’s neat that CERO upgraded the chain and 10-speed cassette to a Gates Carbon Drive belt and ebike rated 5-speed internally geared hub. These tend to be more reliable, require less maintenance, are cleaner and quieter, and you can shift at standstill. A trade-off is increased weight and cost, but I think a lot of people will enjoy this drivetrain.
• Other improvements since the first generation build include internal cable routing that looks nicer, and an upgraded motor that’s more powerful, but lighter and quieter.
• The Shimano E-6100 is one of my favorite “around town” drive systems because it’s dynamic and responsive, measuring rear wheel speed, pedal cadence, and pedal torque, but very efficient and quiet. It offers up to 60 newton meters of torque vs. 50nm on the older E-6050, and looks nicer and more compact.
• It’s easy to miss, but the chainring has an aluminum alloy guard that protects the belt drive, and will keep your pant leg or dress end from getting dirty or snag. Since there is only one front and one rear sprocket on this bike, the belt is tensioned and won’t slap the chain stay or fall off easily. This is especially true because it uses the CDX center-track design by Gates.
• The bike uses all-Shimano parts, and one of my favorites is the Hollowtech spindle that offers improved stiffness and reduced weight. The cranks on this ebike are slightly longer than average at 175mm, which is surprising given the smaller front wheel, but this provides a mechanical advantage to the pedaler and slows the cadence a bit.
• While pedaling the bike during my review, I noticed that the motor seems to provide 120+ rotations per minute (RPM) pedal support. This is great for people who like to pedal quickly or when you have to downshift anticipating a hill. Again, I like this motor.
• The battery pack is excellent, providing a good level of capacity with 36 volts 14 amp hours totaling 604 watt hours. That’s enough to provide 40 to 105 miles of range, depending on assist level because the motor is so efficient. I like that the battery slides out to the side, so the frame tubing can be tight and provide a low standover. I like that the battery isn’t super long or sharp or heavy! It’s easy to buy a second pack for long-range rides and stow it in a bag or backpack vs. some of the newer long, sharp, and heavy designs.
• The battery charger is slower than the first generation, but very compact and lightweight. I love that it uses the same plug interface whether the battery is on or off the bike! This charger is easy to stow and bring along on any ride in case you need a top-off, and since the battery and display panel are removable, you can deter tampering and theft. I’ve been told that storing batteries in cool dry locations is best, and avoid draining to zero or leaving discharged. Between 20% and 80% tends to be easier on the cells.
• The same key and lock used to secure the battery pack are used for the frame lock, to secure the rear wheel. It’s a great setup from ABUS and very practical for quick errands into stores. CERO even sells a chain adapter that interfaces with the frame lock so you can loop around a pole or bike rack for extra security.
• I really like the display panel used here, because it’s large and easy to navigate. There are dedicated buttons to power it on, turn the lights on, cycle through menus, and also navigate through the four assist levels. The display is black and white, but you can invert the colors to optimize for glare or night riding, and the transflective LCD is easy to read in super bright conditions.
• I love that the display shows pedal cadence and range estimate! This is something that only the fancier mid-drives tend to offer, and it seems to be dynamic and fairly accurate. I used both during the review rides. Now Shimano also has an E-TUBE Ride smartphone app with larger readouts and a GPS route planning map. It’s a nice addition to the standard E-TUBE app which lets you adjust the motor performance.
• The bike only comes in one size, but the adjustable-height stem provides lots of fit options. At the top of the stem there’s an adjustable angle section, so you can get more height or increase reach. Of course, the 350mm seat post provides good options for taller riders, to maximize leg extension. Another neat feature is that the handlebar can swivel 45-degrees to make the handlebar align with the frame to fit through tight spaces and take less room when storing.
• I like that the bike is still being sold in multiple colors, blue and gray. I was told that these were most popular (since the first generation bike came in four colors, including black and white).
• I love that safety was considered when adding the bright 2-LED headlight and rear light. Notice the puncture-resistant name-brand Schwalbe tires, and the reflective sidewall stripes that increase your visual footprint. That’s important when the bike sits a little closer to the ground and is loaded with gear.
• Even though the wheel sizes are different, they use matching parts! Both tires have the same branding and pressure range (30 to 55 PSI), which can be lowered for comfort or raised for efficiency. The double wall Alexrims are very nice, and feature reinforcement eyelets to minimize cracking.
• I was delighted to hear that the maximum weight capacity for this electric bike was raised from 270lbs to 300lbs with the new frame. I noticed some additional gusset welding where the top tube meets the head tube, and thicker downtube. I feel that this would be a great ebike for larger people who want approachability and strength, even if they don’t care about the front and rear racks.
• It’s neat that the bike comes with such great racks standard, you don’t have to pay extra. The rear rack has lots of great mounting points and a bungee loop at the bottom. The front tray has a very high 55lb weight capacity and works well with their two basket options.
• Very nice custom fenders here, they’re perfectly matched to the wheel sizes, have a cutout for the belt, and are extra wide to provide good coverage. They did not rattle during the ride tests, and plastic tends to be very light and durable vs. aluminum or steel, which could rust if scratched.
• The Shimano hydraulic disc brakes perform very well, in some ways, the 180mm front rotor is overkill because you also get a mechanical advantage from the smaller 20″ wheel diameter. These brakes are easy to use and have adjustable reach levers which is great for people who have smaller or larger hands.
• The front tray actually has a bottle cage mount on the right side! This is very convenient, whether you use it for fluids, a folding lock, or a mini pump, and it’s super easy to reach without impacting steering. Clever design, well executed :)
• Great kickstand choice, it provides a lot of stability for loading the bike up with gear and then stows compact. It does create pedal lock, but since it’s a double-leg design, you cannot roll the bike with it down anyway.
• High quality comfort-oriented touch points, the Ergon saddle and Ergon locking grips are durable and active but tend to reduce hand and bottom fatigue, which is key on a bike with no suspension. The VP pedals perform well with large surface area and good traction. The half-grip twist shifter is intuitive for riders of all skill levels, and has a big optical window to show which gear is selected.

Cons:

• The price of this ebike has increased since 2017, when I first covered it. You’ll pay $400 more, but you do get something for that extra money: an internally geared hub, a belt drive, an upgraded motor, and a refined frame.
• Since CERO switched from a 10 speed 11-42 tooth cassette to a 5 speed internally geared hub, you get a lower gear range of 263% vs. 382% and fewer cadence options. Benefits include being able to shift at standstill, no derailleur hanging down that could get bumped, and a tighter driveline (belt in this case) that is less likely to fall off.
• It seems that this updated CERO One model weighs about 2lbs (0.9kg) more than the original, despite having a 0.65lb (0.3kg) lighter motor. I suspect this has to do with the internally geared hub and reinforced frame with internally routed cabling.
• It’s pretty cool that the bike comes with a front tray. However, since it’s mounted to the steer tube for strength and the headlight is mounted to base of the tray, it will not point where you steer. I also feel that the headlight is less visible in this position because it’s blocked from above and on the sides by the large tray. There are no side cutouts for light to shine in different directions the way some other lights have… but at least it’s very bright with two LEDs and well protected by the tray.
• There’s no suspension on this electric bike and the front wheel has a higher attack angle and lower air volume (which don’t smooth bumps out as much). Depending on where you ride you might want to reduce the air pressure in the tires to improve comfort a bit (the range is 30 to 55 PSI), consider adding a 30.9 mm seat post suspension but note that it will raise the minimum saddle height by about three inches.
• I love that CERO has switched from the larger 4 amp Shimano charger to a much lighter and smaller 1.8 amp design… and I love that it doesn’t need a dongle adapter to charge the battery off the bike vs. on the bike, but it does take longer to fill because of the lower amp output. I was told to expect ~7 hours for a full charge from empty.
• I wish there was a USB charging port built into the display so you could keep portable electronics charged while riding. Shimano has a great smartphone app called E-TUBE RIDE, which we shown in the video, that provides lots of useful readouts but probably drains your battery.
• This ebike used to be sold in four colors including black, white, blue, and grey… but now it is only available in blue and grey. I guess these were the most popular and it simplifies things for the manufacturer, helping to keep costs from rising too much.
• The smaller front wheel allows the front tray rack to be lower to the ground for easier loading and handling, but this means you have two tire and tube sizes vs. just one. That’s just more to keep track of and fiddle with vs. having standard tires that could both be replaced with the same part at the same time etc. now you have to stock two different parts.
• This is a minor consideration, but the double leg kickstand blocks the pedals from cycling backwards and may get chipped if the pedals do rotate into them. The stand is sturdy, fairly easy to use, and a good choice for a miniature cargo bike like this :)

Useful Resources:

• Official CERO electric bikes website