Mercane hills and slopes (speeds, angles and numbers)

Being who I am, I thought that I needed to make some quick calculations and then go see how close these calculations are against reality. So I went out and measured a few of the roads and found the following:

• the really steep bit at the top of my street (observed in all my videos) is about 10° (so no wonder I need to kick there).
• the steep hill I used on downhill trials was 4° at the first section and then changes to 5° where I started my "rolling start" video.

Using this calculator (and parameters) I obtained this estimate of what I'd anticipate to be the terminal velocity going down a hill of 5°

Here are the calculations for the scooter:

which suggests that I'd more or less hit a peak speed of 16km/h without power, although as you can see the red curve of "power input" doesn't need to be much (nor the slope change) to go into higher speeds. The bicycle is much faster (with its better rolling resistance):

getting to 33km/h without assistance.

So what do I actually get? Well first I thought I'd do what's more 'natural' on a powered scooter and that's just to power down it after turning the corner, which is what I did here.

I got 28km/h on this run, with a headwind which I didn't factor into the calculations. Recalling that the scooter is speed limited to 24km/h I will assume that the motor provides no additional power then I'd expect that the maximum speed at the bottom of the hill to be whatever gravity VS resistance deterimed was my terminal speed.

You'll see that I got to 30km/h (at about the same place) on this downhill run, which isn't really that different. But because I left braking a bit later I could see that the GPS started showing 32km/h. I would wonder if this is because the sampling rate of the GPS speedo is just catching up or if its also that extra bit of hill I ran it down.

Either way this shows a good congruence between that calculator and actual observations in the wild.

Discussion

Its worth noting that in the manual it suggests that you begin applying brake early on a steep hill. This is what bicycle riders would call a coaster brake, where by braking early you simply don't build up a dangerous speed on long downhills (dangerous meaning that if you had to do something unexpected like avoid or stop you could not).

The Mercane essentially has coaster brakes by the internal resistance of that rear hub motor when its not powered.

It may not look like much but in combination with that disc brake and also leaning weight over the rear wheel its an effective system for the speeds the bike was built for.

I'm still tempted by the dual motor version, but in what I do and where I go with this I'm still not sure that its worth the extra money. Certainly not on the commute to work from where I live, nor on most of the journeys I undertake around here. Its just that the steepest parts of town are over to my mates place. However aside from my driveway (also 9° and super bumpy) I can avoid that long steep uphill I've been working with and I can kick a few times for that 9° slope right at the end of my street (or get off and walk it if I'm really that lazy).

So all in all the Mercane Wide Wheel is proving an excellent choice for my needs and 90% of my wants, and as I observe in one of the video's, if I want more speed or power or hill climbing can just use a faster tool (like my motorbike).

HTH