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Strange but ingenious... - Duncan Grimmond - 03-11-2019
I know it's not A7 but nevertheless I found this fascinating, a pal sent me this link to a Megola motorcycle, a 5 cylinder rotary engine in the front wheel...
The first video is a little jerky at the start but but worth putting up with.
https://www.bing.com/videos/search?q=motorbike+with+rotary+engine+in+front+wheel&src=IE-SearchBox&pc=EUPP_&ru=%2fsearch%3fq%3dmotorbike%2bwith%2brotary%2bengine%2bin%2bfront%2bwheel%26src%3dIE-SearchBox%26FORM%3dIESR3A%26pc%3dEUPP_&view=detail&mmscn=vwrc&mid=0DFF5641A5EB57E0F49B0DFF5641A5EB57E0F49B&FORM=WRVORC
https://www.bing.com/videos/search?q=motorbike+with+rotary+engine+in+front+wheel&ru=%2fsearch%3fq%3dmotorbike%2bwith%2brotary%2bengine%2bin%2bfront%2bwheel%26src%3dIE-SearchBox%26FORM%3dIESR3A%26pc%3dEUPP_&mmscn=vwrc&view=detail&mid=33228F60ED6E2D624AA033228F60ED6E2D624AA0&rvsmid=0DFF5641A5EB57E0F49B0DFF5641A5EB57E0F49B&FORM=VDMCNR
RE: Strange but ingenious... - Tony Betts - 03-11-2019
wow.
looks fun.
RE: Strange but ingenious... - Dave Mann - 03-11-2019
Interesting however, I imagine it would be difficult to ride because it wouldn't like to turn a corner, nearly as bad as the WW1 aircraft with rotary engines they never went in the direction you wanted.
RE: Strange but ingenious... - Tony Griffiths - 03-11-2019
Most interesting. I'm sure the Megola has a pressed-steel frame - a type ideally suited to mass production once you have the expensive dies and ideal to double as a fuel and oil tank. However, if the Megola was intended for the mass market it was a dead-end; the engine and front wheel (as Dave points out) had a massive unsprung weight together with an enormous moment of inertia - the effect of which, as one cornered at speed would be most "interesting". To corner a motorcycle say, to the left, requires either a lean (effective at low speeds) or an initial countersteer to the right - this need to countersteer becoming more pronounced at higher speeds, especially on a heavy bike. As the countersteer to the right is applied, gyroscopic precession causes the bike (by interactions through the tyre, etc) to turn left. Now, to get the idea, imagine a front wheel make from solid steel 6 inches wide and 20 inches in diameter travelling at 150 m.p.h. The rotational forces are so high that the wheel, of course, just wants to keep on going forward, and getting that mass to turn using countersteer would need an army of gorillas pulling on the handlebar. Well, the Megola probably could not get beyond 50 m.p.h. and in casual use might have been almost benign in its behavior, but even so....
RE: Strange but ingenious... - Mike Costigan - 03-11-2019
So, you've started the engine whilst the front wheel is off the ground; how do you lift the stand and get under way? They don't show that bit!
RE: Strange but ingenious... - Renaud - 03-11-2019
Hello Duncan,
Indeed strange and ingenious and as we say in french "Pourquoi faire simple quand on peut faire compliqué?" Why make it simple when you can make it complicated?
I find there four silly ideas (at least):
-The heavy rotating engine would provide a giroscopic effect like on the dreadful Solex bike I hated when young
-The same engine will badly add to the non suspended mass at the front
-A simple calculation shows that for 800 rpm the bike would do approximately 60 mph, hmm... No possible clutch and no gearbox.
-I would not want to have any work to do on the engine needing to reach it behind the spokes and certainly not any serious work needing to remove them and then respoke the wheel...
Sorry, but no, I won't buy!
RE: Strange but ingenious... - Steve Clare - 03-11-2019
I saw some much older (1920s?) variations on this theme in a private motorbike collection few years ago.
The mechanic working there was showing how you basically started by bump started the contraptions, and ruefully explaining how terrifying it was to attempt test start or make any adjustments to the engine. If anything kicked off with your hands in there... It doesn't bear thinking about.
But apparently they go along beautifully, and quite powerfully when set up.
see: https://youtu.be/c4Cq49IDfOc
RE: Strange but ingenious... - Colin Morgan - 03-11-2019
Having 'flown' simulations of WW1 rotary aircraft, the rotary engine would help turning quickly one way (but not the other), which could be an advantage. These engines are mechanically complex - not ideal when your life depends on them - especially over enemy lines. (My wife's grandfather was a pilot with the RFC - and somehow survived - skilled, cunning, and very lucky.)
As far as the bike is concerned, some simplifications are not a good idea... it hasn't caught on.
Colin
RE: Strange but ingenious... - Tony Griffiths - 03-11-2019
(03-11-2019, 03:10 PM)Mike Costigan Wrote: So, you've started the engine whilst the front wheel is off the ground; how do you lift the stand and get under way? They don't show that bit!
Having covered his hands with grease, oil and fuel getting the engine going, the hopeful rider would straddle the bike and with, presumably, no clutch and a lever-action hand throttle, lung forwards to push the bike off the spring-retracted front stand. With the tickover set on the fast side to ensure that the engine does not stall (as strictly advised against in the copiously-detailed bedienungsanleitung) the front wheel now grips and the bike lurches forward. The rider (a loose term at this point) is thrown backwards; his hands slip off the handlebars, his right hand makes a futile grab for it, misses and yanks the throttle lever to the full-on position. Now prostrate on the dusty road, our hero watches with some alarm as the bike, nicely stabilised in the vertical position by 50 kg of engine rotating at 2000 r.p.m., accelerates off down the road towards a group of kinder picking flowers on the grass verge....
RE: Strange but ingenious... - Mike Costigan - 03-11-2019
Yes, that's more or less as I imagined it
