This is a common question for anyone getting into eBikes. But it’s really based on how you want to use your electric bicycle.
- Do you want an easy and relaxed ride around the neighborhood while getting some low-impact exercise?
- Do you want to commute through traffic every day?
- Do you want to off-road and climb mountains?
If you are getting an e-bike as a hobby, then power doesn’t really matter all that much. Just about all electric bikes go 20mph, thanks to government regulations in the United States. So the wattage and voltage numbers really only impact acceleration, hill climbing, and the bikes ability to power through dirt, sand and snow. So if you want a bike for weekend rides on the road, while doing some light pedaling, a 24v 250 watt system will work just fine. It is not super fast but is comfortable and easy to control. These bikes are usually inexpensive and a safe way to start out.
Now, if you want an ebike for daily commuting, you are going to need the ability to zip in and out of traffic. When commuting through the city you are going to have to deal with automobiles, and having more power makes this much easier.
For instance if you need to cross a street with oncoming traffic, you want to be sure your bike has the power to get you across before that driver checking Facebook and drinking a Slurpee gets anywhere near you. Power can get you out of trouble, if used responsibly.
For daily commuting, battery capacity (measured in amp/hours) and range is perhaps the most important consideration. For customers in my shop, I recommend at least a 36v 350-500 watt option. 48 volt is even better as you will have better acceleration, but does cost a bit more due to the way batteries are made.
In general, in the United States, the maximum road legal e-bike is a 750 watt motor and a top speed of 20 miles per hour. So just about all e-bike manufacturers stay under 48v 750 watt, anything more the government considers a motorcycle and requires license and registration.
Finally, if you want to use your electric bike off road, then there is no limitation. Go as powerful as you can afford. I have found on mountain bike trails even a 24v 300 watt ebike makes it much easier, but if you want to go fast and avoid pedaling, then go ahead with a 72v 3000 watt motorcycle like the Stealth B-52.
This is all a bit simplified, but in this article I don’t want to get too deep into electrical jargon. Basically what you need to remember is the higher the number on watts and volts, the more torque and acceleration. But just about all ebikes are limited at 20 mph, so keep that in mind.
Personally, I ride a Prodeco Genesis R every day that has a 36v 600 watt geared motor, pictured above. I find this plenty for commuting about 10 miles a day. I like it because it doesn't stand out, so less likely anyone will mess with it when its locked up outside the super market.
In conclusion, don’t obsess over specs, get a bike that fits your use case, you like the looks of, and is well reviewed. It will treat you well. And if you are lucky enough to live near an ebike shop, go take some test rides, often the whole is greater than the sum of the parts. If you are in South Florida come by FarBike and test ride all you would like.