They’re on the Cherry Creek Trail on weekday mornings. They’re parked outside coffee shops on Colfax. You see them on neighborhood streets, on the bike lanes along Broadway, and increasingly, on mountain trails across the Front Range. E-bikes have arrived in Colorado, and they’re not a passing trend.
Colorado has been one of the more welcoming states for electric bikes, offering a clear legal framework, rebate programs, and a growing network of trails and bike lanes to ride them on. That’s mostly a good thing. But with more riders on the road comes more complexity, both in terms of safety and in terms of what happens when something goes wrong.
Here’s a look at where e-bikes came from, how Colorado regulates them, and what every rider in this state should understand before heading out.
The idea of an electric-assisted bicycle has been around longer than most people realize. Early patents for motorized bicycles date back to the late 1800s, but modern e-bikes as we know them began developing in earnest in Asia and Europe during the 1990s. China became the world’s largest e-bike market by the early 2000s, with millions of riders using them for everyday transportation.
The technology and its popularity spread westward from there. Europe embraced e-bikes heavily, particularly in the Netherlands, Germany, and Scandinavia, where cycling infrastructure already existed and the bikes fit naturally into daily life. American adoption was slower, partly due to car-centric infrastructure and partly because the bikes were expensive and the rules around them were unclear.
That changed in the early 2010s, when lighter battery technology made the bikes more practical and affordable. By the time the pandemic shifted how people thought about commuting and recreation, e-bikes were already gaining serious momentum in the U.S. Between 2020 and 2023, e-bike sales in America grew dramatically, with Colorado among the states leading the way.
Colorado law establishes three classes of electric bicycles, and understanding these distinctions matters because the class of a bike determines where it can legally be ridden and what rules apply to its operator.
Bikes are pedal-assist only, meaning the motor only engages while the rider is pedaling, and it cuts off when the bike reaches 20 mph. These are the most common type on shared paths and multi-use trails.
Bikes add a throttle, meaning the motor can propel the bike without pedaling. The motor still cuts off at 20 mph. Class 2 bikes are common in rental and shared-mobility fleets around Denver.
Bikes are pedal-assist, but the motor can continue assisting up to 28 mph. These are the fastest legal e-bikes in Colorado, and they come with more restrictions: riders must be at least 16 years old to operate one, anyone under 18 must wear a helmet, and Class 3 bikes are generally restricted from shared bike and pedestrian paths. They must also be equipped with a speedometer.
All three classes must have fully operational pedals, two or three wheels, and a motor that does not exceed 750 watts. Colorado law treats qualifying e-bikes as bicycles rather than motor vehicles, which means riders do not need a driver’s license, registration, or insurance to operate one.
The Colorado legislature passed House Bill 25-1197 in 2025, which added new requirements around battery safety, labeling, and sales practices. Starting January 1, 2027, all e-bikes sold in Colorado must carry a label showing the bike’s class, top speed, and motor wattage. Lithium-ion batteries must now meet safety certification standards from an accredited lab, and it’s illegal to sell or advertise a vehicle as an e-bike if it doesn’t meet the state’s definition.
Those battery requirements are worth paying attention to. Lithium-ion battery fires have caused injuries and property damage across the country, and the 2025 legislation was a direct response to concerns about cheap, uncertified batteries making their way into the market.
Generally speaking, Class 1 and Class 2 e-bikes are allowed anywhere a traditional bicycle can ride, including roads, bike lanes, and most multi-use paths, unless local rules say otherwise. Class 3 bikes are limited to roads and bike lanes.
Denver has its own rules worth knowing. Riding an e-bike on sidewalks in Denver is generally prohibited except where expressly permitted. The city’s trail network has its own set of rules that can vary by location. Before riding on any specific trail, it’s worth checking with the trail manager or the city directly.
E-bikes are also allowed in all 42 Colorado state parks that permit mountain biking. Federal lands are a different story: e-bikes have historically been restricted on non-motorized trails in National Forests and some Bureau of Land Management areas, though rules have been evolving.
Most people who buy or rent an e-bike just want to get around, enjoy the scenery, or cut their commute time in half. That’s completely reasonable. But the legal landscape around e-bikes matters for a reason beyond avoiding a ticket.
If you’re involved in an accident on an e-bike, whether you caused it or someone caused it to you, the class of the bike, where you were riding, and whether you were following the applicable rules will all become relevant. Colorado’s roads are busy, e-bike accidents are increasing, and the legal questions that follow a crash can be complicated.
Understanding the basics is a good first step. We’ll get into the accident picture in the weeks ahead.
Scott O’Sullivan has been representing injured Coloradans from his Denver office for over 25 years. If you have questions about an e-bike accident, call The O’Sullivan Law Firm at (303) 388-5304 for a free consultation. There’s no obligation, and you’ll speak directly with an attorney.
