First a trickle, then a flood: That pretty much describes the availability of ebikes in the US over the past two decades. Most of the earliest ebikes sold in the US were from European companies; now, nearly every major bike company in the US and abroad has introduced its own line of ebikes. Here’s how we decided what to test out of those many, many bikes.
Our number-one priority: electrical safety. Far too often recently, we’ve seen reports of a bike or its battery bursting into flames while charging. In September 2023, New York City began requiring that every electric bike sold in the city be certified to the UL 2849 standard and that any bicycle battery be certified to the UL 2271 standard, and we chose to make such certifications a criterion for this guide, as well.
The New York law mandates that bikes have not just their batteries certified but also the bike’s entire electric system, including the charger, wiring, motor, and controllers. We expect that similar requirements will spread to many other parts of the country, as well as to many private housing associations and communities.
It’s an industry-wide standard that everyone we spoke to at every bike company, regardless of whether its models had received UL certification yet, agreed was the right call. (Some manufacturers are still waiting on approval, and we plan to consider their bikes as those approvals roll in.)
A close second: mechanical safety. We looked for sturdy frames—aluminum, generally—and stable, non-twitchy geometry.
All the bikes we tested had motors that provided somewhere between 250 and 750 watts of power, as 750 watts (equivalent to just under 1 horsepower) is the maximum power allowed for a street-legal ebike in most parts of the US. For context, a typical recreational cyclist might be capable of producing just 100 watts, and the winner of last year’s Tour de France, Tadej Pogačar, was averaging nearly 450 watts on the race’s toughest climbs.)
You can find many bikes advertised online that claim to be street legal (that is, capable of 750 watts maximum) but have much more powerful motors with switches or codes that allow them to run in an “off-road mode” or “race mode.”
Not surprisingly, some people ride such bikes, illegally, at those more powerful settings on public streets, behavior that has prompted calls for stricter enforcement. This brings up one of the difficulties of legislating ebikes, because there isn’t really a set way to rate the power of an electric motor—the rating that the motor’s manufacturer gives corresponds to the power at which the motor will constantly run without overheating, which can mean different things based on the provided cooling and other factors.
Legality and public nuisance aside, overpowered ebikes can be dangerous in the hands of young or inexperienced riders. We’ve steered clear of such bikes in our research and testing.
After safety, durability was our next biggest priority. This is where we began to encounter some difficult truths. The wear sustained by a bike used for commuting can be surprisingly high: Just a few miles a day can add up to thousands of miles in a year.
No matter what any marketer may claim, all mechanical systems need maintenance (at least as far as we know). With electric bikes, the complications involved in repairing their systems challenge the traditional advantages of commuting by bike: that bikes are accessible, inexpensive, and easily maintained over a long product lifespan.
To explain how this affected our choice of which bikes to test, I need to discuss ebike drive systems. The two most popular designs are hub drive and mid-drive. Hub-drive bikes typically use a motor in the rear hub to directly propel the bike at the wheel. Mid-drive systems employ a motor installed at the base of the bike’s pedals to add power and torque to what your legs produce. In comparison with hub-drive systems, mid-drive systems have a more natural, “bicycle-like” feel and leverage the gears of the bike to generate much more usable torque (what helps your bike accelerate and climb hills) at the rear wheel. Changing a rear flat is also easier on a mid-drive bike, as you don’t have to deal with the complications of the hub motor. For all of these reasons, we originally focused our research on mid-drive bikes.
However, the mid-drive systems we looked at combine all of the electronics, the motor, the torque sensor (which tells the motor how much help your legs need), and every bearing involved into one compact package between the cranks, whereas the hub-drive systems spread the elements out. As a result, if any one of the parts on a hub-drive bike fails, replacing it is significantly cheaper and easier. Having all of the parts in one unit—as they are in a mid-drive system—that can be repaired or replaced only by the manufacturer isn’t something we want to encourage for a utilitarian vehicle meant to be operated cheaply and sustainably over the course of a multiyear lifespan. So we widened our scope to include hub-drive bikes.
We looked for bikes designed for commuters. That is, we preferred bikes with integrated lights, which don’t need to be removed for charging, and a rear rack, if possible. (A rack-and-pannier system affects a bike’s handling less than a handlebar basket does, and putting your gear there is less sweaty than carrying it in a backpack.) We prioritized bikes with a fairly upright and comfortable riding position that naturally keeps your head looking ahead and your shoulders relaxed; this is what almost every bike looks like in countries where a significant amount of the population commutes by bike, such as the Netherlands.
To test the bikes, we wanted to simulate a fairly difficult commute in terms of elevation gain while keeping it close to an average round trip in distance, so we tested every bike on the same 8-mile course in the Mojave Desert, with a series of hills increasing in steepness up to around a 15% grade. We also tested the limits of each bike’s climbing ability by tackling one of the steepest streets in California, which has a grade of over 30% (none of the contenders were great at this task).
