Has a conceptual C.G. problem, alas.

Post #420,250 by Ashton 9/9/17 9:20:38 PM 9/9/17 9:20:38 PM Reply	Has a conceptual C.G. problem, alas. (Yes I quite remember the [-]s of the gorgeous Lambretta) scooter-with faired-in gadgetry: tiny wheels, etc.) My first New machine, post- Whizzer moto-bike. 'Decent range' might appear in such designs as above, agreed. But One needs Large wheels aka (actual dia. != misleading er, Tyre-sizes. ..not to mention the picky geometries of fork rake/trail, axle-height-above-ground + other subtleties. Simple focus: You.. able to move about (occasionally even partly-stand a bit, moving your weight-locus down to foot-pegs (while you cannot "compress-down"! much!) plus Machine static CG determines the road manners + ballistics. You thus alter the ∑CG (and will need to..) Just observe the commonality of sizes/placements on Any serious expen$ive Racers to note how these shapes converge. Your pic looks Purty but.. [see above, where the Rubber meets the Road]. I wot that: Language + studies of Newton, basic mech. engineering etc. all have their places, but Simply, I see no substitute for a course in Lessons-learned at-speed, and on a variety of 'models' as you can lay hands+feet on, to derive any useful guesstimate of where any next actual-Improvements might lie. My compressed recipe is ~~ [unlikely to convert anyone] It's quite non-algorithm-able, this [Problem of Man + Machine] at lethal velocities. e.g. Can recall a borrowed Velocette small single: execrable power-unit, torque, Noise etc. BUT.. It was light! w/ Lovely frame/suspension design as inspired confidence to try damn-near Anything. (This you test with Engine Off!, a "coaster race" down say, "O'Shaughnessy Ave in S.F. !?) No torque available to SYA, y'see? Ya gots only brakes + road-cuth. You can learn Lots. Or drop the plot ez. {{sigh}} Nope, no magic clean-sheet of Paper I've ever seen: worked first try. (The awfulness of certain scooter-like devices, esp. in any evasive maneuvers: Experienced! Once ... tells one more than any 'analysis paralysis' can. Sure, New! and Better incremental designs Will occur next (too) but my overall ∑ View is that Truly those [++]s come about via ART. Which we must count on for lots of matters, Right? Vroooom ----> ... but on a New thing? Stay focussed and anticipate {the unExpected}, while wearing leathers, nice helmet/gloves and humility :-) [Geoff Duke, John Surtees You Ain't]
Post #420,255 by Another Scott 9/10/17 10:34:42 AM 9/10/17 10:34:42 AM Reply	Good points. I dunno enough about all the issues, but that general layout seems to have several examples (including from BMW and Suzuki). They're much bigger than the empty bike looks. 100 mph top speed is plenty. Presumably being able to stash battery cells almost anywhere would give more flexibility on the CG than having an IC engine. And the people wouldn't have to sit so high if a huge covered carrying capacity wasn't needed. But it will never handle like something like this... ;-) An electric version of something like those Honda, Suzuki, or BMW scooters would seem to make a lot of sense for commuting in dense urban areas. A lot more sense than self-driving cars... ;-) Cheers, Scott.
Post #420,280 by Ashton 9/11/17 6:39:03 PM 9/11/17 6:39:03 PM Reply	PS.. re that top pic Just CAN'T let that color-glossy sit there un-disparaged, y'know? Red-flag.. WRONG is: Exactly (in height) ---> where this pair-of-butts sit: -vs- The C.G. of all the gearhead-bits, way-too-far_below.. There; you are on STILTS! Especially-awful with Two-Up. (Passenger if unskilled is dead-weight; cannot even Try to 'help'.) Needs no words; The pic all-alone suggests well, the Difficulties a pilot Will endure/(or not survive) with any need for a rapid maneuver. (And look well at the height! of your boot-soles!) == lowest-point you Can place your body-weight to influence matters, i.e. Because, also too the wheels are too-Small dia. for rest of chassis {sigh} Cornering demands here, as with a scooter, needs road-clearance == why they had-to place foot-rests ^where^ they did. :-/ You just Can't! use your body as you Need-to, to ameliorate [Your + machine's] combined C.G. (thus to apply physics to S. Y. A.) {{sob}} Rest case. Racer pic below: illustrates the shape-map for function: just torn-up by Boobus Marketus. Std. Advertainment-pulchritude fantasy OVER all hard-won authentic-lore to date. Yeah they likely will peddle n of these. I hope to Drumpf voters (as would never notice 'science'.) Just like glamorous Giant-'Hog' Ad-pix of Harleys, old Indian Chiefs ..with about same %mass given-over to sexy-sheet-metal cosmetic shapes ..as-in Detroit-iron of the days of Insolent/Heavy Chariots -vs- [all aspects of Basic design-physics] You can get away with that in 4-wheelers.. sorta, but NOT with 2-wheel-equilibrium! (I'd likely drive one of these around the block. Carefully. I drove a foot-clutch Harley.. Once.)
Post #420,282 by boxley 9/11/17 7:07:28 PM 9/11/17 7:08:04 PM Reply	ignore, forgot the link "Science is the belief in the ignorance of the experts" – Richard Feynman Edited by boxley Sept. 11, 2017, 07:08:04 PM EDT Expand All History
Post #420,283 by boxley 9/11/17 7:07:38 PM 9/11/17 7:07:38 PM Reply	put a battery in one of these I would be interested http://www.polaris.com/en-us/slingshot "Science is the belief in the ignorance of the experts" – Richard Feynman
Post #420,285 by drook 9/11/17 7:55:17 PM 9/11/17 7:55:17 PM Reply	I don't understand those They're not motorcycles. They aren't weatherproof. I can't think of a use case that something else isn't a better choice. -- Drew
Post #420,286 by Another Scott 9/11/17 10:07:03 PM 9/11/17 10:07:03 PM Reply	They're 3-wheel go-carts. For adults.
Post #420,290 by scoenye 9/11/17 11:06:05 PM 9/11/17 11:06:05 PM Reply	It is an opening for those not/no longer comfortable on two wheels but for whom a convertible is too "square". Trike conversions have existed for a very long time. Having the two wheels up front eliminates the differential problem and the Slingshot opens the market wider by having a steering wheel.
Post #420,309 by static 9/13/17 2:55:54 AM 9/13/17 2:55:54 AM Reply	People still buy 'em. BAC, Ariel and Caterham (and likely others) have four-wheel cars like that and they seem to be successful. There was a memorably Top Gear challenge where the hosts got to use some of these cars in daily driving. Except it rained that day. :-) Wade.
Post #420,306 by a6l6e6x 9/12/17 5:03:07 PM 9/12/17 5:03:08 PM Reply	Highway police bait! :) Alex "There is a cult of ignorance in the United States, and there has always been. The strain of anti-intellectualism has been a constant thread winding its way through our political and cultural life, nurtured by the false notion that democracy means that "my ignorance is just as good as your knowledge." -- Isaac Asimov
Post #420,288 by Another Scott 9/11/17 10:26:53 PM 9/11/17 10:26:53 PM Reply	Good points, but... I envision them being used for commuting on urban interstates, 35 MPH roads, etc. Not tooling down the PCH or cutting through the Alps on a beautiful summer day. At least that is what I would use it for. The guy I saw on a red Honda version a few years ago must have been around 70. Energica EVA electric superbike. 617#, 124 mph top speed, 50-60 mile range when whooping it up, $35k+. :-/ It's got a ways to go yet. But it's good that people are trying! Cheers, Scott.

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