Friday, 25 October 2019

scooters are not motorcycles

Frequently the conversation on on-line forums attempts to compare scooters and motorcycles. Personally I'm dumbfounded; because to me anyone who's ever even seen a motorcycle in the flesh must be clear that these things have only one thing in common:
  1. two wheels
Everything else in almost every aspect of physics and operational dynamics is entirely and utterly different.

That such comparisons persist can only be
  • the person has lived such a sheltered home life as to have done nothing more than just look at pictures
  • an indicator of being so ignorant as for it to be shameful (but usually they agressively defend their positions)
  • a sign of such complete and utter self delusion as to border on being mentally restricted to a developmental age of about 15 years old
The most common comparison is in braking (lets leave cornering or speed out of this), which the scooter can never compete with a motorcycle and its beyond me as to why I even have to make the obvious clear, but it seems people delude themselves continually still. I've written this post because I'm sick of repeating myself on forums and so I'll simply post this link from now on.

Firstly lets look at my Mercane wide wheel beside a basic "chook chaser" dirt bike (so nothing even fast).


Stopping

The most common myth is that motorcyles have greater than 70% of their braking power on the front wheel (which is true) and so scooters should too (which is not true). Lets get to the first point of delusion "powerful front brakes are needed" so looking at these two I've got the front contact patch of both front wheels aligned. 

Now imagine that someone is standing on the scooter, if you aren't standing almost over the back wheel of the scooter you'll have your weight so far forward and so close to the front wheel its almost begging to pivot around that front wheel and face plant you into the ground. This is why people who have experience and understand reality often say that a strong front brake is a liability on a scooter.

Notice how the most massive part of the dirt bike is right over the back wheel of the scooter? Almost the entire mass of the motorcycle is back to the point of being behind where most people stand (crowded up at the front post). 

Here I've added the relative masses and locations of the Center of Gravity  (CofG) of both the motorcycle and the scooter, the black center of mass of the rider and bike are much bigger than the blue one of the scooter. There is a balance point between gravity (yellow line) and braking forces (red line) Next note how much further back (and heavier) that is on the motorcycle than it is on the scooter?


Notice how far that has to move befoe it goes past the tipping point (which is about when the black or blue line becomes vertical) ...  the scooter CoG is just asking to flip it at the slightest provocation. 

Thus if you use the back brake it can't flip ... obviously right?

EDIT: Now, here's an interesting thing, notice the angle of that black line? Its pretty close to 45 degrees, which would indicate that a motorcycle can stop with a force at about equal to gravity, or about 1G. I just decided to look on youtube for any tests on motorcycle braking vs car braking, guess what I found? I found that a car can brake at 1G and that while an experienced rider (who trains) can stop at 1G too, that most riders were half that ... well worth watching this:



So looking at the even steeper angle of the scooter (its almost falling over before you hit the brakes I'd put it at far less than 0.3G

Next the deluded will just repeat that the rear wheel will skid as the braking forces unload it ... and so this is why I always say "stand back and lower your weight as part of braking", this transfers the weight over that wheel and keeps it on the ground and helps you to stop faster ... so make it a habit.

Relative Weights

Then there is the fact that the scooter itself weighs essentially nothing compared to you. Typical adult human weight will be over 80kg yet the scooter is like 24kg ... in contrast the motorcyle will be over 100kg and then look at the angles of center of gravity where the rider sits (and note how far back it is from the place you've probably been standing. So on the motorbike you're likely to be half or less of the mass, on the scooter you'll dominate the weight.

So your legs are an important (critical) part of the suspension and why scooter suspension is more about just a bit of comfort and not what suspension is really all about, which is
 >> keeping the wheels on the ground<<

Keeping them in contact with the ground so that braking can happen, and cornering can happen.

On the scooter "you are part of the suspension"

Even on an old little 100cc road bike like this, the scooter is clearly just a toy beside it


and again, those same principles mentioned above are there:
  1. how far the center of gravity of the rider is positioned(the arse point on the bike is again right over the rear wheel)
  2. the center of mass of the much more massive motorcycle (this one weighs more like 120kg)
  3. you have strong handle bars to push against and support your weight

So please, if you're riding a scooter, keep the speeds to intelligent levels (less than 30kmh (which is under 18mph for anyone still in that measurement past)) and know that stopping this thing will take time. 

If after reading this you persist in the view that a scooter can stop better and more safely with a powerful front brake then you're at a level of self delusion that is beyond help.

Lastly

If my tone seems harsh, well I can assure you that the consequences of failing to believe this and to train appropriately will be much harsher.

What would I know? Well I've had motorbikes since I was about 12 and grew up riding motorbikes on the farm from about 10, below is just some of my road bikes since 1985

I've ridden motorcycles in more countries over more years and more kilometers than probably most people (although I know some who have ridden more and more diverse than me) ... but I doubt that anyone with much experience (or as we say in Australia "much of a brain") would even be arguing that scooters can stop as fast (from the same speed) as safely as a motorcyle or that scooters should have super powerful front brakes.

So, the King is dead, long live the King ... King Wang


Best Wishes

Friday, 18 October 2019

A year with the A7 (brief thoughts)

so, its been a year with the A7 now. Its been an interesting and informative journey.


I can say that the A7 has been an more of an addition to my photography but has not replaced the micro43 system I have. They do things differently (especially with the same lenses).

The m43 is entirely adequate, video too is sufficient and its backed up by a better set of lower priced native lenses.

Of course that I can use my non-native lenes (by adapter) on both means that the A7 just added a body to my set of (older 70's legacy) lenses and this essentially changes what those lenses do and how the images render ...

For instance the FD200mm f4 lens is quite telephoto on the m43 (equating to 400mm) but is a lovely mid telephoto with nice DoF on full frame (the A7)



... which I simply could not do without something like a 150mm f2 lens in m43 (which I'm not sure even exists, certainly not for the $100 I paid for the FD).

However despite how compact it is with the nice little SamYang (top picture) it has not managed to really pull me over from using the GF-1 with the Panasonic 20f1.7 lens


which is such a sweet little bokeh maker and on the GF-1 (for which it was made) is a compact easy to carry on a hike little bit of kit. Interestingly, both the 20mm on the GF-1 the 35mm Samyang on the A7 are almost exactly the same angle of view.

Of course what I want Full Frame for is also shallow DoF, but in portrait lengths ... which the m43 also does but the A7 does just that bit better.



So this body has really added dimension to my kit while only costing a small amount.

Win Win

Sunday, 6 October 2019

Dual vs Single: power proving a theory (or two)

When I bought the Mercane dual motor Wide Wheel it was also to clarify a point.

I knew (of course) that the 1000W (pair of) motor(s) would provide much better hill climbing (that much was obvious), and my use of a calculator (explored in this post) made that an expected outcome. Experiencing it was actually more fun than I'd expected.

However what I was unsure about was this: did more battery translate to different range between the two scooters when there was double the motor? Given that there were a few considerations to make:

  • twice the torque on hills must use more power
  • however at fixed speed (governed by the speed limiter) power needs would be more or less the same between the scoots on a flat path
  • the dual will have a bit more rolling resistance (which I've measured as being about double) due to the additional motor
  • 422Wh battery on the Single and 633Wh on the Dual = 50% more battery on the Dual but 100% more power


The answer it seems is that having more power available does not use that much more battery, it actually gives a greater range. and this has been emerging as a picture in the fact that I've been able to go places, which are hilly, that I couldn't do on the single.

Hypothesis Clarified

Yesterday I went for a scoot with a mate and he took the single and I took the dual. The route is below:


The red arrow is where the single motor ran out on the way back.We walked along for a while (about another 1.5 km and then decided to do a "tow" where he balanced on the scooter and put a hand on my shoulder and I towed him. Of course I had to accelerate slowly and we found that a speed of about 10kmh was pretty ideal.

So this means that for the remaining (about) 2km the dual motor pulled him and me. I can say from the pressure on my shoulder that a few kilograms of force was needed to get him rolling and while of course less a few kilograms needed to keep him rolling.

My dual motor scoot was still at 49V when we got back to the car.

He had a great time (as did I) and the entire thing was a great fun afternoon with a bit of "team building" type cooperative behaviour tossed in for good measure.

Take outs:

  • The Dual motors is amply compensated for by the 50% increase in battery.
  • My friend had never scooted nor used a skateboard, but done a fair bit of rollerblading, so had the basic intuition for good balance. After the basic safety introduction (braking and stance) I moved into teaching him that balance is through your feet, and that if you feel wobbles in the bars its because you aren't balanced on your feet.
  • He picked that up pretty fast and within a few km was exporing which foot was better back and agreed that while one is naturally dominant that being comfortable with both is important
  • After he'd had 10 km on the Single I gave him the dual and he was impressed by the extra power
  • People love these things almost immediately and find that doing trips on them is just great fun.
The second theory I proved is that basic instruction makes a huge difference in learning curve and confidence levels (and growth of them) in a novice. There probably should be courses for scooting.

Happy Scooting

Friday, 4 October 2019

Mercane: prep for riding and regular "keep an eye on its"

Firstly this is about the Mercane Wide Wheel, but its applicable to ANY SCOOTER in a general way.

I thought I should do a post about general and preventive maintenance on the Mercane (as I've already done a few here in a piecemeal manner).

I think its important to note that these eScooters are toys, not "motor vehicles" which must conform to DoT safety standards and other engineering standards. They don't and they're assembled by (probably) unqualified people who probably did not know as much (perhaps as you) when they started and (unlike you dear reader) didn't have anyone to make any suggestions to them.

As it happens the Mercane is fundamentally a sound design, robust in many ways, but not immune to poor assembly, mainly the lack of thread locker.



So with that in mind I'd say its prudent to do all of the following yourself:
  • from day 1 remove (one at a time) each external fixing bolt (all under the belly pan for a starter) and put a drop of permatex blue on it (or a light loctite), put just a single drop and put it on the tip. This will prevent vibration losses of those bolts.
  • remove and decently tune the brake caliper (make sure that the caliper clears the disc and that the inside pad is put close to the disc to avoid that "bending over" phenomenon
  • plug your charger in and turn it ON before plugging into the bike (avoiding electrical erosion of the plug and bike side contacts ... the plug is a high quality XT60 and is gold plated for good contact, why fuck it up right?
  • periodically pull the base cover off and check that all bolts are snug and no signs of deforming the washers is present on the steering head stem attachment bolts.
  • get a short length of aquarium tube (about 3 inches) the right diameter and use it as an outer protector for the rear brake cable run, it rubs on the chassis ... I'm about to inspect the drive side cable too, so you may want to look at that yourselves too, but I don't think its as big a problem due to the angles ... but worth looking right?
  • always note that your handlebar rings properly seated when you raise them. They're tapered and spring loaded (make sure you see the springs are working. I've seen one person complain of a folded bar soon after getting on.
  • while not exactly maintenance be careful with big gaps in pavement, as these are actually very hard 90° impacts like a hammer and chisel and if you happen to be turning or leaning (say avoiding something) will hit the tyre edge on and you can see the result on mine.
  • recently I felt that there was some play in the swing arm** so I took those covers off and (again one at a time) removed the retaining bolt of the swing arm and added a drop of permatex onto that too (see video below showing the bolt I mean as well as my blog post here). If it feels tight (mine was loose as I expected from the movement I felt) then leave it alone.
  • while you have those covers off examine the axle nuts (that hold the wheel from falling off), finger tightness test them and if you feel any movement then they're fine. If you are sus just give them a quick tightness test with the supplied spanner. remember "leftie loosie righty tighty" for direction of turn
  • I've recently added a video on how to adjust your brakes once they're properly set up here
  • lastly I'd say a bit of added foam in the battery compartment is handy as the battery is held in by velcro, which is super strong and prevents shocks from being transmitted to the battery, but thigns like cables in there rattle a little. Now it is important to not block the holes in the battery base which allow drainage and some cooling air flow (important both of them. I used this).
Just as a follow up I think its important to mention that the permatex blue that I use is this, and an image I snagged off the web is this:


I don't have experience with the tooth paste tube style pack gel they are selling too. Anyway the key (meaning important) words in that are:

  • OEM specified. All-purpose, medium strength threadlocker.
  • Ideal for all nut and bolt applications 1/4? to 3/4? (6mm to 20mm). 
  • Eliminates need for stocking expensive lock nuts and lock washers. 
  • Locks and seals while preventing parts loosening due to vibration. 
  • Protects threads from corrosion. 
  • Removable with hand tools for easy disassembly. 

Read the directions on that page if you're unfamiliar with it ... myself I just make sure that the bolts are cleaned with a rag (and ours on the eScooters aren't likely to be oily...)

** As mentioned above this is the swingarm bolt which I was talking about (although the loose one was the rear on my Mercane single motor (which seems to have suffered the most from crappy assembly)


I recommend you watch this video, but you will not need to remove anything more than the side cover to access this.


I've since added a bit more on that on my blog here.

Happy Scooting

Wednesday, 2 October 2019

Public Perceptions

On of the things about riding the scooter is that while its legal (meaning also authorised) its only just become so where I live (and still isn't in other areas). So with that in mind I think its important to put the message out there to ride safe as well as having fun.



Whizzing past people may seem fun to you, but can frighten others and cause a swing of public opinion against scooters as valid transport.