Electric assist bikes (eBikes) are a great way to get into biking if you’re not confident about your physical abilities, or if, like me, riding a standard bike up Wellington’s hills has become frustrating. But some people are worried about how fast eBikes go, and feel that they will pose a danger to riders of standard bikes. So how much faster are eBikes than standard bikes? The answer seems to be “not much”.
First, what does the published research say? The German Naturalistic Cycling Study (2017) found that eBike riders averaged only 2km/hr faster than people on standard bikes. Langford, Chen and Cherry (2015) found that eBikes averaged faster on roads (21km/hr vs 17km/hr) but slower on shared paths (18km/hr vs 20km/hr). Note that this was in the US, where eBikes are allowed to have more powerful motors. This study demonstrates that while eBike riders potentially have more speed, in places like shared paths they may choose not to use it. They also found that people had similar safety behaviours, whether they were riding eBikes or standard bikes.
Next, I decided to see what happens in NZ. I spent a few hours on Wellington commuter routes, timing eBikes and standard bikes over about 100m, generally using lighting poles as markers. I found that eBikes averaged 26km/hr, standard bikes 23.4 km/hr, a difference of 2.6km/hr. This was a small study (9 eBikes, 55 standard bikes) with a crude method for measuring speed, but seemed to indicate that eBikes fell in the same range of speeds that standard bikes do. The fastest bike was a standard bike, and the slowest an eBike.
It would be good to get a bigger sample, but I was getting tired waiting for the occasional eBike – although they’re becoming more common, I still had to wait a while between eBikes, and sometimes I’d fail to recognise them in time.
So I turned to Strava, where keen people with GPS smartphones can record their activity when biking, running, and even hand cycling. Strava has an Activity Search which although a bit erratic in its searching, allowed me to compare ordinary bike rides (“rides”) with “E-Bike rides” that had been recorded in NZ. Strava gives a lot of data about each ride (I was tempted to compare the total calorie intake of eBike and standard riders!), but I used the average speed and the maximum speed, and searched for rides recorded in Auckland, Wellington and Christchurch. I used 132 eBike rides, and 145 standard bike rides.
On average, eBikes had an average speed 2km/hr slower than standard bikes (20.7km/hr vs 22.7km/hr). The average maximum speed for a ride was pretty similar: 49.3km/hr for eBikes, 49.6km/hr for standard bikes. This makes sense: if you’re going fast downhill, it doesn’t matter if you’re on an eBike or a standard bike – gravity is doing the work.
There some caveats to the Strava data. People who record their rides on Strava are interested in performance, and probably go faster than “ordinary” riders. Some people mis-labelled their rides (in one case, an “eBike ride” was actually using a BloKart), though I think I was able to weed these out. My sense was that the eBike rides tended to be more utility oriented than the standard bike rides, which tended to be recreational sport rides. This could explain why this study shows eBikes averaging slower speeds than standard bikes. There was probably a broader range of individual riders among the standard riders than the eBike riders.
So what can we conclude about eBike speeds, and whether they are a threat to people riding standard bikes, or walking on shared paths? eBikes are “designed to be primarily propelled by the muscular energy of the rider” so in theory people using them should behave similarly to people on standard bikes, and the research seems to show this. In fact we have a range of types of bikes and riders, that tend to travel at different speeds. A lycra clad rider on a dropped handlebar bike training for the Taupo Cycling challenge will travel at a different speed than someone heading down to the dairy on their upright city bike. It looks like eBikes are just another kind of bike, and their speeds fall into the same general range as other bikes.