Motorcycle Ideas

[kengeorge]

Hi Everyone
               Just a little something I saw yesterday and thought I'd share it with everyone as it does tie in with the beginning of the thread... http://www.dailymail.co.uk/sciencetech/article-2009009/Chris-Malloy-hoverbike-Helicopter-pilot-invents-worlds-1st-flying-motorbike-garage.html .

Thanks
KenGeorge

[pyro-manic]

Good grief, that article made me cringe. The dim movie references, and the way they called the Chinook a "twin-propeller helicopter".

Interesting contraption, though it's very unlikely to get certified IMO.

[jcf]

The Mail really needs to hire a research department.  First flying motorbike?, not by over fifty years

http://www.aviastar.org/helicopters_eng/bensen_b-10.php







Looks safe, don't it? 

Anyhow skycycle concepts are old and I think we've wandered a bit off-topic, as they aren't really motorcycles.

[KJ_Lesnick]

Weaver,

I think a feet-forward bike is not a good idea.  I think the new Tron movie's bike looks pretty cool provided it had an aerodynamic windscreen up front (not a covered canopy) and a configuration that would allow more steering control so it would have a reasonable degree of agility.  It would be pretty cool if somebody built a motorcycle with a turbocahrged wankle engine in it...

[Hobbes]

That would be a unique combination.

There have been a few Wankel-engined motorbikes, but none of those were turbocharged. Turbocharging is rare anyway on motorbikes. There was a Honda a couple of decades ago (750 cm³?), but performance bikes nowadays can get 180 bhp from ~1200 cm³ so there's little need for turbocharging.

[Weaver]

Wankel bikes:

Norton Rotary (in various forms) : in low-level production for quite a long time and had some racing success. Killed off mostly by business shenannigans that sunk the tiny rump Norton company. Enthusiatic owners' club (I know one).

Suzuki RE5: small production run in 1970s. Over-complication to address rotary problems made it heavy and expensive compared to equivalent conventional bike so it didn't sell well.

DKW Hercules: late '60s, early 1970s? (Don't know much about this one) Basically okay, but expensive for it's performance level so didn't sell well.

The basic problem with all Wankel engines in rotor-tip lubrication. In all the examples above, this was via a total-loss oil system using a special oil, and it's only thanks to the continued existance of the Mazda rotary cars that this oil (Shell Rotella) is still available. A bike can't carry a big oil tank, so rotary owners either have to carry extra or plan their routes around places where they know it's available. Weekend tours are fine, but world tours are out without elaborate back-up.




Turbo-bikes:

There was a brief fashion for turbo-charged bikes in the early 1980s. As Hobbes says, the blistering performance of conventional bikes made it's complication and problems redundant.

Honda CX500 and CX650 turbo
Yamaha XS650 turbo
Kawasaki GPZ750 turbo
There was also a Suzuki but it was never imported into the UK ( "XN85" or something like that?)

Of those, only the Kawasaki was moderately successful, and then only (mostly) because the next size up conventional bike, the GPZ900R was actually 904cc and so fell just the wrong side of the simplistic 900cc capacity limits which insurance companies used to rate bikes in those days (there was no "group" system like there was for cars: that's changed now). Speaking of insurance, note that all those bikes had medium-sized engines and so theoretically qualified for lower insurance than bigger conventional ones. This was the probably the primary reason for their existence, but the insurance companies quickly wised up and stuck a premium on anything with a turbo, so even that rationale quickly evaporated.

A fundamental problem which affects all turbo bikes is throttle lag. Basically, you open the throttle and get some more power instantly, but then the power keeps building for a constant throttle setting as the turbo winds up to the new speed. This is very disconcerting: you open the throttle for the next straight and the bike speeds up, then just before the next bend it speeds up again all on it's own! The basic solution in cars is to put the turbo right next to the exhaust ports, thus minimising the delay before the exhaust gas velocity at the turbo increases, but it's hard to package a bike like that, and three of the above had the turbo behind the engine with long pipes leading to it and consequent turbo-lag. The Kawasaki was better than the rest because it's turbo was in the belly pan on the end of relatively short exhaust headers, but that in turn brought it's own problems with water, rust and dirt.

BMW were great fans of supercharging back in the 1950s, the layout of their flat twin engines being particularly suitable. They keep looking at it again every few years, but no production hardware has ever resulted. Peugeot, however, have produced a small-capacity supercharged scooter which has been relatively successful.

[Weaver]

Just got this from a Hongkong company on ebay: 1/12th scale "Sexy Moto Girl".





It struck me that I could make a hovering speeder bike by taking the wheels and runing gear off a modern sports bike and putting some sci-fi greeblies in their place, and then use a rider, with feet on the ground, to hold it up, rather than using clear rods and the like. A few strategically placed pins and wires (don't think too hard about that or your eyes will water... ) and she should do a treat.

Thought I might side-step my total inexperience with painting big human figures by making her alien: green skin, purple hair, gold suit....

[rickshaw]

Err, there's a bike there?   

[ChernayaAkula]

Looked for it on eBay and found it. The ebay ad doesn't mention "Legend" anywhere. Is it an original by Legend or is it a recast?
HERE'S the original, named "Need for Speed", on the Legend website.

<...> It struck me that I could make a hovering speeder bike by taking the wheels and runing gear off a modern sports bike and putting some sci-fi greeblies in their place, and then use a rider, with feet on the ground, to hold it up, rather than using clear rods and the like. <...>

That was my thinking as well.  Been thinking of doing one of the hoverbikes from "The Island" as a racing version with this figure.

[Mossie]

It struck me that I could make a hovering speeder bike by taking the wheels and runing gear off a modern sports bike and putting some sci-fi greeblies in their place, and then use a rider, with feet on the ground, to hold it up, rather than using clear rods and the like. A few strategically placed pins and wires (don't think too hard about that or your eyes will water... ) and she should do a treat.

Like this?
http://melonhead118.deviantart.com/art/Jet-Bike-39737350

[Mossie]

and then use a rider, with feet on the ground, to hold it up, rather than using clear rods and the like. A few strategically placed pins and wires (don't think too hard about that or your eyes will water... ) and she should do a treat.

Much as I don't want to distract you from the young lady , another way of doing a dio would to be involve a race or high speed getaway, the guy taking around a bend with his knee brushing the surface.  Maybe add a rival with a bit of light contact???

[raafif]

way to go 'n ruin a good bike with ½-necked women 

How about these ...

[Weaver]

ChernayaAkula: it's probably a knock-off, judging by the total lack of info that came with it. I'd never even heard of the Legend figure.

Actually, rather than a modern sports bike with it's deep fairing, I'm now thinking more about the Suzuki Katana. It always was trying to look like a space fighter, and it's shallow bodywork means that you can make the flying bike much shallower, with less of a "wheel-shaped-hole" at each end.

Basically, turn this:



Into this (very, very rough):



An added bonus would be that you could nick the Kat's GSX-1100E engine and put in in a custom chop frame as I discussed earlier. There used to be LOTS of things like that about on the UK custom bike scene.

[kitnut617]

Here's a weird one



and this was forwarded to me recently   

[Weaver]

Heh - there have been a few variations on that kind of "motorcycle girl" over the years....