Most U.S. e-bikes cap motor assistance at 20 mph for Class 1 and 2 models, and 28 mph for Class 3 models.
The speed question is the first thing most riders ask, and the honest answer depends on which of the three legal classes the bike belongs to. Federal definitions set the ceiling for what counts as a low-speed electric bicycle, but the motor cutoff is not the same thing as how fast the bike can physically travel. Here’s what the limits mean, how they break down, and where the law stops mattering.
What Are The Federal E-Bike Speed Limits?
Federal consumer-product law 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 motor-only top speed under 20 mph on level ground with a 170-pound rider. That definition anchors everything else.
From there, the widely used three-class system sets the actual assist limits:
- Class 1: motor assists only while you pedal, and stops assisting at 20 mph.
- Class 2: motor can propel the bike without pedaling via throttle, and stops assisting at 20 mph.
- Class 3: motor assists only while you pedal, and stops assisting at 28 mph; these bikes commonly require a speedometer.
The Congressional Research Service and USDA Forest Service both repeat these same 20/20/28 mph thresholds in their summaries of e-bike law on federal lands.
Can An E-Bike Go Faster Than The Motor Cutoff?
Yes, but the motor won’t help you get there. The class limits are motor-assist ceilings, not absolute speed limits for the bicycle itself.
If you pedal hard enough on a Class 1 bike on a downhill, you can exceed 20 mph — the motor just disengages at that point and you’re powering the bike entirely with your legs. The same applies to Class 3 bikes above 28 mph. The cutoff is a line where assistance stops, not a governor on the wheels.
This distinction matters because riders often confuse “how fast the motor will push me” with “how fast the bike can go.” On flat ground with the motor working, Class 1 and 2 bikes settle at 20 mph, and Class 3 bikes at 28 mph. Add a hill or a headwind, and the motor may not be able to maintain those speeds at all.
Do State Rules Match The Federal Classes?
Not always. Federal class definitions establish a baseline, but state and local rules can be stricter, and the federal class speed does not guarantee legality everywhere.
Some states cap Class 3 bikes to certain roads, limit where they can ride on trails, or impose age requirements and helmet laws that don’t apply to Class 1 and 2 models. Others treat e-bikes differently depending on whether the motor is throttle-driven or pedal-assist only. Before buying, check your state’s specific e-bike statute rather than assuming the federal 28 mph ceiling applies everywhere.
Class 3 bikes are the fastest mainstream category in U.S. law, but that speed comes with more restrictions in many jurisdictions. If you’re choosing between classes, the trade-off is usually top speed versus where you’re allowed to ride.
What About “25 MPH” E-Bikes And Higher-Power Models?
Bikes advertised at 25 mph or higher generally fall outside the federal low-speed e-bike definition unless they meet the 750-watt and pedal requirements.
That doesn’t mean these bikes aren’t available. If you’re set on a faster model, it’s worth understanding the legal trade-offs before you buy, since the rules that apply to standard e-bikes may not cover it. For a tested rundown of options in that speed range, our roundup of the best 25 mph e-bikes covers the practical picks.