What difference does an ebike make?

You may have spotted that I’ve had an ebike on loan for the last six weeks—a Nihola eTrekking (about which, more here).

I’m just finishing off the full review of the Nihola, but I wanted to split out the generic “electric” stuff from the specifics. Things that would probably apply whatever ebike you got your hands on.

Thanks to the power of VeloViewer we can do lots of exciting1Your idea of exciting might differ from mine, admittedly, but we’re in my playground, so I make the rules data analysis. That comes first, and then some more general points follow.

The test

A bit of context.

I’m comparing the two bikes shown at the top of the screen: my non-electrified Kona Sutra, and the Shimano Steps-assist Nihola eTrekking (with a UK-legal motor, so it cuts out at 25kph). Both weigh about the same (seriously, that Sutra is heavy), both have Schwalbe Marathon tyres (slow and durable), both have 1×9 or 1×10 gearing. For both bikes, I’m carrying a single large-ish pannier.

The route is my commute, which is a 42km round trip, covering rural and urban areas. Inbound has 147m of elevation, and outbound 301m, both with gradients up to 11%.

In total, we’re looking at 17 return journeys. I wore a heart-rate strap for all of them, becuase I’m that much of a nerd.

The data

Out of all the things we could look at to assess the impact of electric assist, I think the most relevant are:

  • The average speed.
  • The average moving time.
  • Strava’s relative effort score (which is a fancy way of estimate how “hard” the ride was, based on heart rate and some other stuff).

I’m using box-and-whisker plots, which are an excellent way of showing the shape of data (Wikipedia’s description is here, but we’ll talk through it as we go).

For all plots, I’ve shown the inbound and outbound journeys seperately due to the elevation differences.

Average speed

Average speed graph. Note y-axis starts at 15kph

The impact of the motor is less on the inbound journey—with average speeds hovering just below the 25kph cutoff for the motor, most of the time you get no benefit. However, there’s still an increase of 2kph on the median2The median is one of four different statistics that could be called the “average”. It’s the middle value, if you ordered all the things from smallest to biggest. time, and the fastest inbound commute (average of 27.9kph) was my fastest ever, including on the racing recumbent.

The hillier outbound journey is where the assist shines, with a 5kph increase (ie +30%) on the median time. Even the slowest assisted time was over 3kph faster than the fastest unassisted trip.

Let’s see what that means for journey time.

Average moving time

(We’re using moving time because I often stop off at the shops on the way home, and measuring moving time ensures that doesn’t affect the results. It also means that bad runs of traffic lights are discounted as well.)

Average moving time graph. Again, y-axis starts away from zero.

This is the key chart.

On the inbound journey the difference is again noticeable, but we’re only talking a median saving of six minutes.

However, look at the outbound comparison, where the motor is in use for what felt like about 60% of the time:

  • All the electrified trips were within three minutes of each other (53-56 minutes). That’s pretty damn consistent, if you rely on your bike to get to things on time.
  • The motor takes 15 minutes off the median time, and 19 minutes off the max (ie those tired, uphill, into-headwind slogs home).

Adding those median savings together, that’s 21 minutes a day. Over 220 working days (roughly average if you work full time in the UK), that’s 77 extra hours with the kids3Or eating cake.

Strava relative effort

We’d said above that Strava’s relative effort metric is a way of assessing how hard a ride was, mainly based on cardiovascular effort. It’s a dimensionless number, and bigger numbers are harder work4For context, my top three hardest activities by this metric are two rides around the 100km mark that were above my endurance pace, with scores of 515 and 500, and then an off-road half-marathon at a score of 450.

From the chart above we can see that whilst the motor clearly makes it easier, work is still being done. My easiest outbound unassisted commute (ie the minimum) was only a little above the median effort of the assisted outbound rides, despite having the assist set to high the entire time. Amazingly enough; if you push hard on an ebike, it’s just as hard as if you push hard on an unassisted bike (you just might go a little faster).

That being said, my easiest outbound assisted commute was really rather gentle—if you’re willing to “sit back” on the motor, you can make good progress with very little input. You just won’t go as fast as if you put some effort in5I’ll take about this more in a separate post, but most good ebike motors work as an effort multiplier, rather than a flat addition of, say, 150 watts power. Therefore the effort you put in directly affects how much extra power the motors adds on..

You can draw your own conclusions from this, but here’s two. If you’re holding back from an ebike because you’re concerned you won’t get the same amount of exercise, you can be reassured that you’ll still be burning off a good slice of cake each commute. On the other hand, if you want to be less tired at the end of a long day and are willing to let the motor do most of the work, an ebike will absolutely do that.

Some more general thoughts

That’s the objective data analysis done with. Let me finish with some subjective feedback.

  • Ebikes are without a doubt a tool that will get more people out of their cars and into cycling, with benefits for their health and the health of those around them. Those who cycle already should encourage this.
  • There is still some snobbery around ebikes, and it not being “real” cycling. We’ll talk more about this in a separate post, but if this is you, bear in mind there are mums and dads that will be delivering kids to nurseries and schools on ebikes in the depths of winter long after you’ve hung up the summer carbon and dug out the turbo. Who’s the real rider now, eh?
  • Riding a good, torque-sensing ebike (ie one that multiplies your effort, rather than adding on a constant lump of power whenever you turn the cranks) is very similar to riding an unassisted bike with a constant, strong tailwind. There’s very little learning curve.
  • The exception to that is on surfaces with poor traction. If you put the foot down on a greasy bend and forget your motor is doubling your overall power output, you will lose your rear wheel.
  • When mixing it up in urban traffic, you can get out of an awkward spot very quickly on an ebike. Your acceleration away from traffic lights beats almost anything else on the road.
  • Nothing lifts the spirits after a long day at work, facing an uphill homeward commute into a stiff headwind, than knowing there’s an ebike waiting for you…

Right, that’s your lot! The Nihola review will follow in a few days (providing I survive the week now I’m back on the ol’ unassisted iron horse…)

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Thanks for the informative review on this. Easy to digest and also lets people see how it might work in real conditions.

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