20 Dec 2018

20th December 2018 I really wouldn't start from here!

*

Thursday 20th 39F very dark grey distant mist and promised to be wet for most of the day. It duly started raining as I donned my boots for my morning walk but had stopped by the time I reached the end of the drive. A peculiar day of patchy blues skies and low cloud. The mist accentuated the sense of perspective but was difficult to capture with my cyclopic camera.

Following on from yesterday's monologue on alternative vehicle widths: The width of the vehicle is vitally important to stability and comfort.

Anyone who has ridden a delta trike knows how easy it is to lift the inside wheel when cornering. The effective track of a trike is even narrower than one would think. A line has to be drawn between front and rear, road contact patches to form a triangle. The trike can only tip along these hinge lines along the ground. It does NOT tip along a line parallel to the rear wheels.

Trikes can't be ridden on banked cycle tracks because the center of gravity falls outside the tyre contact patches. The rider literally falls down the banking because they cannot achieve sufficient centrifugal force to stay on the track with the speed attainable by a human being.

The same holds for rutted farm tracks. So trikes are not the correct starting point for "alternative" narrow electric vehicles for city driving.

A quadricycle is a much better and safer starting point. Simply because of its inherent stability with a wheel right out at each corner. OR THEY SHOULD BE! Aka: THE BMC MINI.

Before that most cars had heavily inset wheels. Worse, they were inset front to back as well as side to side. Stability was discarded for mere styling. They look very odd to us today because we don't remember them being so narrow in track. With huge, cantilevered boots and bonnets further inhibiting stability. They rolled and wallowed and pitched and yawed. The Mini literally ran circles around the dated opposition.

A narrow quadricycle still needs help if it is to travel above a human's jogging pace. It must lean inwards on corners. Preferably to a variable degree depending on the speed and sharpness of the curve. The inward leaning should also improve comfort. The passenger's center of gravity is effectively lowered instead of flattening them against the surfaces of the vehicle.

A gyroscopic stability system might well keep the vehicle flat on the road but the passengers would end up laterally flattened themselves. It would feel very unsafe in motion because of their constant rocking from side to side with every minor change of direction and camber.

A narrow quad really ought to sit automatically upright on cambers too. The narrow track greatly magnifies the lean of the vehicle on any camber. The inner and out wheels sit on a tangent to the camber's curve. The narrower the track the more extreme the lean.

Most ordinary cars have very similar wheel tracks and curved, bucket seats. A bench seat is very uncomfortable and causes the passengers to slide from side to side because it does not support their buttocks laterally. In a moving vehicle the whole body pivots around the buttocks.

I hope I have shown that there are enormous hurdles to overcome in providing the masses with narrower cars for city use. Most of these problems are simply geometric as a direct result of the narrower track. It looks so simple but you cannot fit two narrower vehicles side by side on the same width of road as a single, much wider car. They both need room on both sides. A lane is never just a parallel lane. It has obstacles, like drains, potholes and puddles. The car in the outer lane has oncoming traffic to cope with.

99.9% of the time overtaking the vehicle ahead is an exercise in futility and utter delusion. You have risked your life and that of your passengers to gain one car length on the road. You have simply replaced one rear bumper for another. The reality is that you have chosen to give yourself an adrenaline kick just for the sake of it. You have gained nothing in reducing your journey time.

They say that one cannot reinvent the wheel. Yet you still see designers trying to foist recumbent electric tricycle "velos" will never sell to an unsuspecting public. I do not believe that the masses would ever seriously consider an electric recumbent ANYTHING. They are just too damned difficult to get in and out of! They are also extremely claustrophobic and the driver is blinded by their lack of view of the surroundings.

Using a heavy battery pack in the bottom pan just to achieve lateral stability will be a very short lived solution. Better batteries, or capacitors, will soon eclipse the present, tightly packed, AA lithium batteries.
 
Click on any image for an enlargement.




*

3 comments:

  1. Hello there I have a velomobile (allewedder) and a recumbent trike, and your right threewheelers are a bad idea... now that i,m retired i dug out my holdsworth monsoon fitted with a rogers axle and went for a ride , it was awful like riding on ice i,d forgot how bad it was, Are all single wheel drive trikes this bad, have you got any tips before i take an hacksaw to it (joking)








    .

    ReplyDelete
  2. Hi Robbo, I feel your pain, but I can only suggest a fine toothed, hacksaw blade. If you want to go electric, to stay ahead of the curve, then try a rechargeable angle grinder. ;-)

    ReplyDelete
  3. Check this out:

    https://youtu.be/7eHfksutiUQ

    https://youtu.be/Fa6CoF2IYhM

    ReplyDelete