Has the Manually Shifted CVT Made a Comeback? 

"Berang" (berang) 06/09/2015 at 09:18 • Filed to: friction transmission, ner-a-car, metz, lambert

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What you are looking at is the engine and gearless transmission of a 1923 Ner-A-Car motorcycle. In the pioneering years of the automobile, gearless “friction” transmissions were popular - and then they vanished.

The friction transmission was a very simple form of “gearbox” which did away with many of the early problems of sliding gear transmissions by simply omitting the gears and clutch altogether. The photograph at left should help make clear how the thing worked. On the back of the engine crankshaft a large aluminium disc was mounted.Behind this was an axle carrying a wheel at right angles to the aluminum disc. When the wheel was brought into contact with the disc power was transmitted from the disc through the wheel, to the axle, and then by chain to the differential and drive axle. The ingenious bit is that the friction wheel could slide back and forth on its axle and be brought into contact with the aluminum disc at various positions along its diameter - effectively giving various “gear” ratios. In theory this would allow for infinite adjustability of ratios, but in practice the ratios were limited to a selection of stops along the friction wheel’s travel. But having a five or eight speed transmission when most cars had two speeds, and doing away with gears in an era before synchromesh existed meant that in many ways friction transmissions outdid their geared competitors.

The Lambert automobile was the first make to successfully use this style of transmission, but the limitations of friction drive became apparent as cars got heavier and more powerful. As well, clutch and gearbox technology progressed rapidly and the early advantages of the system were no longer so advantageous. By the 1920s this type of transmission was well on its way out, with the lightweight Metz cyclecar and the Ner-A-Car motorcycle being stubborn holdouts against geared transmissions.

By the way, The Ner-A-Car motorcycle looks like what I’d imagine a Taish era Kaneda would ride.

The title of this article is admittedly a bit of a trick. As there are now modern CVTs which allow one to choose from a selection of preset ratios mimicking a gearbox - but as has been demonstrated above the idea is not a new one. It’s an old one that’s come back with the help of newer, better technology. The possibilities available haven’t yet been fully explored (24 preset speeds like a bicycle? a floor mounted shift lever? a manual clutch pedal? who knows what the future might hold?). Although personally I’d still rather have a Ner-A-Car than a Subaru Forester.

And if you’re a real nerd, here’s !!!error: Indecipherable SUB-paragraph formatting!!!

Ner-A-Car photo credit to !!!error: Indecipherable SUB-paragraph formatting!!! .

spanfucker retire bitch > Berang 06/09/2015 at 09:23

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I can only imagine how inefficient that is in terms of power delivery.

random001 > Berang 06/09/2015 at 09:27

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Great post! Thank you!

RamblinRover Luxury-Yacht > spanfucker retire bitch 06/09/2015 at 09:33

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Pretty inefficient - but like a modern trans, less inefficient in high gear. In low gear you get relative slip from left to right on the driven wheel of as much as ~-50%/+50+, but in high gear, it’s more like -12%/+11%. All that slip is waste energy and heat before you even get to less than perfect input/output match (relative slip) of probably several percent and general drivetrain/other friction losses. Still, this setup works great on lawn mowers and tillers:

(Best known for it - the “Snapper” brand)

Smallbear wants a modern Syclone, local Maple Leafs spammer > Berang 06/09/2015 at 09:35

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I hope so. I want a continuously variable manual shifter for my CVT.

RamblinRover Luxury-Yacht > Berang 06/09/2015 at 09:36

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Similar setup was used on the GWK. I know in their case, the friction disc was pressed paper.

Patrick Nichols > Berang 06/09/2015 at 09:37

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I think CVTs could be the next thing for enthusiasts if they just gave us a dial or handle (similar to a boat throttle) that gave us a seemingly infinite number of ratios instead of the preset ones that try to make a CVT feel like a traditional automatic.

I don’t get the point of trying to push technology forward and then marketing it by making it look and feel like the old technology, especially to enthusiasts who never liked the traditional slushbox.

Tekamul > Berang 06/09/2015 at 09:38

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My snow blower has the same transmission. It works well enough, but it tends to get a little stuck when it sits for too long. If I forget to bump the ‘shifter’ a bit to free the wheel, engaging the drive clutch makes the drive belt for the 2nd stage pop off. It’s pretty annoying.

Berang > RamblinRover Luxury-Yacht 06/09/2015 at 09:41

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The Lambert used the same. The designer had experimented with several materials and finally settled on aluminum and compressed paper.

Berang > Patrick Nichols 06/09/2015 at 09:48

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It’s an interestin phenomenon, people don’t like change. Sort of how old word processors did green text on black because it was easy on the eyes. But then it was changed to black on white (which is hell on one’s eye when the white is glowing) because people wanted their word processor to look like a piece of paper.

Patrick Nichols > Berang 06/09/2015 at 10:48

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True, but in this case isn’t limiting the number of possible ratios to the same number of gears an auto would have inherently inefficient?

Berang > Patrick Nichols 06/09/2015 at 10:58

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I think limiting it to 4 or 5 ratios would be silly, but let’s say one could “lock” onto a particular ratio along the continuum that would in certain circumstances be useful, and in others it may just be fun. That’s something that could be taken advantage of with new CVT tech.

LordPandamonium > Smallbear wants a modern Syclone, local Maple Leafs spammer 07/09/2015 at 19:17

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Give it a sequential stick. Then maybe the unlimited shifts in fast and furious might be a reality.