How you plan to use your e-bike may leave you little choice on the class you select. For example, I live near the Torrey C. Brown Rail Trail where I put as many miles riding on the trail as I do on the road. Since the only class allowed on the trail is a Class 1, my only choice in is a class 1 if I want to continue using the trail.
On the other hand, if I used my e-bike as a commuter where assistance up 28 mph would help me ride safely in traffic, and I wasn’t concerned with traveling longest distances on a single charge, a class 3 bike might be my only choice.
Finally, if you want a bike that doesn’t need to be pedalled, a Class 2 bike is the only one that would fill the bill.
Initially, when I was shopping for my e-bike I thought that the most important factor to increase my range would be the size of my battery. So I wanted the biggest battery I could find, in my case 840 watt hours. It only made sense to me that the bigger the battery the farther it would take me.
While it’s true that a higher capacity battery would take you farther if everything else remains constant, the vast majority of a battery’s power is used to move the air around you unless you’re climbing a steep hill. To make matters worse, as speed increases the power needed to overcome air resistance increases with the square of the velocity
Since the power needed to increase speed is not linear,
For example, based on data from Cycling Power (road-bike.co.uk) and other sources, it takes about 120 watts to ride at 15.6 mph. However, it would take about twice the power (250 watts) to increase the speed to 20 mph and more than six times the power (about 750 watts) to reach 28 mph.
In terms of range,
Increasing speed from 15.6 mph to 20 mph will reduce range by about 50%.
Increasing speed from 15.6 mph to 28 mph will reduce range by a staggering 85%.
Before choosing what e-bike class is right for you, consider if speed or range is the most important factor to you. You can’t have both. If range is the most important factor, I would opt for a class 1 over a class 3. This will optimize your range and reduce the temptation to be seduced by speed. If speed is your biggest concern a class 3 is the only bike that will provide assistance beyond 20 mph.
In the world of cycling, faster is better! Right? So when I started shopping for an electric bike, I instinctively focused on the fastest e-bikes I could find. That mindset immediately narrowed my search to class 3 e-bikes. Class 3 bikes are the only class that provides assistance up to 28mph. Class 1 and 2 bikes only provide assistance up to 20 mph.
I never really considered how often I actually ride at 28 mph. In reality, unassisted I generally only reach 28 mph on the downhills. Even then, that’s about the speed I start thinking about gently applying my brakes to safely maintain control of my bike so I can maneuver around obstacles I might encounter on the roadway. I know I’m not alone here. After checking Strava, I found the median cycling speed is somewhere around 15 mph.
In addition to not feeling natural riding at higher speeds than I normally ride, there was another unexpected consequence I hadn’t considered.
While I’ll admit it was a thrill to pick up my speed to 28 mph on a safe straight section of road, I feel that the class 1 bike rides at speeds closer to the speed I feel most comfortable riding and that drivers can more accurately judge my speed to safely interact with me on the road. So when choosing the e-bike class that is right for you, consider how fast you ride now and if you would feel safe riding significantly faster.
Choosing the e-bike class that is right for you is a huge consideration when purchasing a bike. That said, while U.S. bike manufacturers and suppliers have agreed on the three e-bike classes below, not all states have. So, before buying a bike check your state’s laws and regulations first. A good place to start would be with MOVING E-BIKE LAWS INTO THE FUTURE.
THREE E-BIKE CLASSES:
CLASS 1: Bicycle equipped with a motor that provides assistance only when the rider is pedaling, andstops assistance at 20mph. CLASS 2: Bicycle equipped with a throttle operated motor and stops assistance at 20mph. CLASS 3: Bicycle equipped with a motor that provides assistance only when the rider is pedaling, and stops assistance at 28mph.
In my case I ride on both roads and trails. While a class 3 might be a good choice for the road, most of the trails I ride only allow class 1 bikes. So if I want a bike that will do it all, a class 1 bike is the only choice for me. On the other hand, if I want to use my e-bike for commuting and not on trails, a class 3 bike might be the better choice.