Sunday 22 December 2019

Bicycle VS eScooter (and conjecturing an eBike)

I went out yesterday morning around one of my regular roads on the bicycle (which is a basic MTB {Giant Roam}) and decided to just "pace" around, not breaking any records, not dawdling. I got this:


You can see the ups and downs in speed corresponding to small hills and as you can see its only mildy hilly.

So this morning I took the scooter on the same path and got this


Notice how much more even the speeds are? It's far more constant (thanks also to the cruise control, which I would never have a scooter without...) and you see almost no deviations down in speed due to up hills and about the same maximum downhill speeds, although the bicycle did make better advantage on down hill with longer durations and a higher peaks speed (probably influenced as much by rolling resistance {scooter worse}, wind resistance {about equal} and my speed limiter being 24kmh on the scooter).

So this suggests that if I was interested in commuting and my trip leg distance was higher than 10km that I'd be better off with an eBike than a scooter because basically on the bicycle I was the only power and on the scooter I put no power into it at all. I'd say that I could maintain a constant 30kmh on the milder hills, still reach 44 on the down hills and bring my average speed up significantly probably 10kmh over the scooter and all that with probably only 500W needed (some times).

Indeed my favourite bike calculator suggests I'd probably only need to be pulling 200W from the motors to maintain 30kmh (given what I was already doing) and that even up steeper than the steepest grades I'd only need another 200W on the way up.

This lends support to why eBikes get by with less battery and manage longer distances with that.

PS: I didn't think this deserved a separate post,  but just did another quick (shorter) trip and got this (more or less just into the shops in town and back without stopping).

Bicycle



Scooter

Note: there seems to have been a GPS issue which appears on the map where I seemed to jump across country so the distances seem off, but the speeds and duration clarify things still.

  • higher down hill speeds on the bicycle
  • more slowing on the quite minor hills (scooter was clearly well within its power and torque for max cruising speed on them)
  • slightly quicker on the scooter
My observations and comments are that the scooter can be walked into the shops (which I do) but the bicycle (and of course an eBike) couldn't. I didn't get the slightest bit sweaty (and it was early morning as you can see and temps are still low, recalling that its summer in Australia now). The scooter is very quick and convenient for such small trips, however one has to constantly survey the road for bumps roughness which on the bicycle would be unneeded (well obviously huge potholes) because my MTB has 700 wheels and a basic entry level telescopic fork making it smoother than any 8" wheel (even with suspension) ever could be.

If you haven't read this I recommend it, allow me to quote the relevant portions on why a scooter is inherently more dangerous than a bicycle.


Smaller Electric Scooter Tires Have More Problems with Obstacles

Most electric scooters have tires measuring 6-8 inches in diameter. This is far smaller than the average bicycle tire of 25 inches. When encountering an obstacle the smaller tire (scooter) has a much harder time going over it.
The chart below shows the additional force needed by a scooter to overcome a step compared to a bicycle.  This graph was plotted assuming a 26″ bike wheel and 8″ scooter wheel.
The chart below shows the additional force needed by a scooter to overcome a step compared to a bicycle.  This graph was plotted assuming a 26″ bike wheel and 8″ scooter wheel. (see also)

And I hope that the following diagram makes totally clear why that energy rating is so, as while both wheels have to raise up 1 inch, the impact to forward momentum on the bicycle is quite different (look at where the obstacle is relative to the center of the wheel, most of the wheel is already past it on the bicycle, allowing the rest to roll over it, but not on the scooter.

Happy Scooting

No comments: