Elliot wrote:Hey, I have an inquiry:
One of my projects is to invent The Ideal Transmission for my pedal-vehicles. This will be a chain gang, somewhat like used on some British "cycle cars" of old. I think I have the design figured out -- except for the control mechanism. Or... actually... the tried-and-true automobile four-speed H-pattern floor-shifter would serve well, if it were scaled down. And actually, I only need four positions, so a 3-speed shifter would do (using reverse for the fourth position).
(Yeah, you are all thinking "Hurst" right now.)
Sure, I could fabricate 20 (eventually) of these. But time is precious. Maybe they are out there? Ford Pinto? A lawn tractor?
Elliot wrote:You are correct, the riders will need to be in approximately the same gear, or some will not be able to contribute. But people have different pedaling habits. Some are "spinners", meaning they pedal fast with low torque, say 80 RPM. Others, like me, are "stompers" and are happier at 65 RPM. With two or three bicycle derailer arrangements in series, such fine-tuning is normal.
This however, is NOT an issue in my scheme. This proposed arrangement has only four gears, and they are very wide apart in ratios. So no slight variation in cadence will be possible. This is an acceptable tradeoff for having a fool-proof system. Most of the problems Kinetic racers have along the route involve bicycle-size chains and derailer stuff.
So the idea is to use only four gears, but build them bomb proof. Motorcycle chains. Yes, all the riders will need to get into the same gear as the terrain changes, but they will be able to make the shift un-hindered by the others. See... it is difficult to get two people to synchronize their shifts, specially if they are not familiar with the machine. And then one would not be able to shift while the other is still pumping. So we want none of that "Ready for downshift, three, two, now!" Then "Wait everybody, I got stuck!"
One rider, one transmission. If one rider shifts early or late, no harm done to the others. That's why 25 trannies, eventually.
Also, with the reductions we use, one person can generate enough torque to break some serious steel. I've seen two people tear a #40 chain (small motorcycle) in half. And I had four people shatter a pretty stout-looking differential out of some industrial machine. So it is best to split them up -- one rider, one tranny, one wheel. Also allows the machine to shrug off any one mechanical failure.
The picture show "Henry Ford Goes Surfing" a few years ago. Four completely independent drivetrains, each rider to his own wheel. Pretty much unstoppable, except that the trannies were inadequate.
ygmir wrote:could you not gear the common shaft, before it goes into said motorcycle transe up, so as to offset your 60:1 sprockets or whatever?
do you ever use a heavy flywheel?
name redacted wrote:I was at the vintage automobile races at Laguna Seca many years back. The picture above reminds me of a 3 wheeled racecar that had a harley engine mounted in front of the front wheels.
ygmir wrote:what I'm seeing there, Elliot, is you taking the submissive/missionary position, with an ominous looking buzz sawish (sprocket) set to punish you........are you sure of your story?
Captain Goddammit wrote:I'm almost certain that bare chassis with the chain gang transmission is indeed a 1930s Fraser-Nash.
The very noticeable positive camber of the front wheels is a particular trademark of those cars as well as the chain drive setup.
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