The legal e-bike speed limit depends on which class of bike you’re riding. Class 1 and Class 2 e-bikes stop providing motor assistance at 20 mph. Class 3 e-bikes assist up to 28 mph. Federal law sets a separate cap of 20 mph for motor-only propulsion, meaning the motor alone cannot push the bike faster than that on flat pavement. Pedaling adds whatever speed your legs can produce, and the posted speed limit of the road or path you’re on still applies.
Speed Caps by Class
Most e-bike regulation in the United States runs on a three-class framework. Over three dozen states and the District of Columbia use it, and federal land agencies rely on the same definitions. The classes differ in how the motor helps and when the help cuts off.
- Class 1: Motor assists only while you pedal and cuts off at 20 mph. No throttle.
- Class 2: A throttle can propel the bike without pedaling, but assistance still cuts off at 20 mph.
- Class 3: Motor assists only while you pedal and cuts off at 28 mph. Most Class 3 bikes have no throttle, though some jurisdictions allow one that cuts off at 20 mph on a Class 3 frame.
All three classes share a 750-watt motor ceiling under federal law and under the rules used by the National Park Service and Bureau of Land Management.1National Park Service. Electric Bicycles (E-Bikes) in National Parks A bike that exceeds either the wattage or the assisted-speed cap falls out of these classes entirely and is usually regulated as a moped or motorcycle.
What Federal Law Actually Sets
The federal number comes from 15 U.S.C. ยง 2085, which defines a “low-speed electric bicycle” as a two- or three-wheeled vehicle with fully operable pedals, an electric motor under 750 watts, and a maximum motor-only speed below 20 mph on a flat, paved surface when ridden by a 170-pound operator.2Office of the Law Revision Counsel. 15 USC 2085 – Low-Speed Electric Bicycles A bike that fits this definition is a consumer product under bicycle safety standards, not a motor vehicle under highway safety law. In practical terms, you don’t title, register, or insure it the way you would a car or motorcycle.
The federal statute does not cap how fast you can go when you combine pedal power with motor assistance. A Class 3 rider pedaling hard downhill can exceed 28 mph, and no federal provision alone makes that illegal. The posted speed limit for the road or path still governs. A Class 3 bike legally capable of 28 mph of assistance must slow to 15 mph in a 15-mph school zone, same as any vehicle.
The statute includes a preemption clause that overrides state laws “more stringent” with respect to low-speed electric bicycles as consumer products.2Office of the Law Revision Counsel. 15 USC 2085 – Low-Speed Electric Bicycles States still freely regulate where e-bikes can ride and who can ride them.
How State and Local Rules Change the Number
States that use the three-class system generally mirror the federal thresholds: 20 mph for Class 1 and 2, 28 mph for Class 3. Details vary. Some states cap all e-bikes at 20 mph regardless of class. A few impose wattage limits below the federal 750-watt ceiling. A handful of states haven’t adopted the three-class framework at all and apply their own definitions, which can trip you up if you ride across state lines.
Cities and counties add their own layer. A municipality can restrict e-bike speeds on specific roads, paths, or downtown corridors beyond what state law allows. Many cities ban e-bikes from sidewalks entirely. Before you ride somewhere new, assume the local rule may be tighter than the state rule.
Where You Can Actually Use Those Speeds
The number on your bike matters less than the infrastructure you’re using it on. Class 1 and Class 2, with their 20 mph cap, are the most broadly accepted. They’re generally allowed on multi-use paths, bike lanes, and any road open to traditional bicycles.
Class 3 faces tighter access rules because 28 mph creates real risk around pedestrians and slower cyclists. In most jurisdictions, Class 3 e-bikes are limited to on-street bike lanes and roads, and many shared-use paths and recreational trails prohibit them. If your commute includes a stretch of multi-use path, confirm Class 3 is allowed there before you buy one.
Speed and Access on Federal Land
National parks and BLM-managed lands set their own e-bike rules, and the two agencies handle them a little differently.
National Park Service
Under NPS regulations, e-bikes may be allowed on park roads, parking areas, and trails where traditional bicycles are already permitted. Each park superintendent decides which classes to allow and on which specific roads or trails.1National Park Service. Electric Bicycles (E-Bikes) in National Parks A superintendent might open a road to all three classes and restrict a multi-use trail to Class 1 only. Riders generally cannot use a Class 2 throttle for extended stretches without pedaling, except on roads open to motor vehicles.3Federal Register. General Provisions – Electric Bicycles All e-bikes are banned from federally designated wilderness areas.
Bureau of Land Management
On BLM lands, e-bikes sit outside the “off-road vehicle” definition only when the rider is on a road or trail open to non-motorized mechanized use, the motor isn’t propelling the bike exclusively for extended periods, and the local authorized officer has specifically decided to treat e-bikes the same as non-motorized bicycles.4eCFR. 43 CFR 8340.0-5 – Definitions The BLM rule opens no trail automatically. Each local office makes that call through its own planning process.5Bureau of Land Management. E-Bikes on BLM-Managed Public Lands Check the specific park or BLM unit’s rules before you go.
Modifying the Speed Limiter
Removing or bypassing the factory speed limiter is where riders most often cross into real legal trouble. Manufacturers install limiters specifically to keep the bike within its legal class. Once the limiter is gone, the bike may no longer qualify as an e-bike at all.
If a modified bike exceeds 28 mph of motor assistance or runs a motor over 750 watts, most jurisdictions treat it as a moped or motorcycle. That reclassification brings a cascade of requirements: DMV registration, a valid driver’s license or motorcycle endorsement, and mandatory liability insurance. Riding an unregistered, uninsured modified e-bike on public roads can lead to fines or vehicle confiscation, depending on where you’re caught. Modification also voids the manufacturer’s warranty, and pushing past the factory ceiling can shorten battery life, overheat components, and raise crash risk at speeds where injuries get much worse.