The "Parachute Effect" - Any Ideas?

Yup, same article. I didn't agree so much with the handling issue.
I do think the Majesty is suceptible to sidewinds due to the large body size of the sides - and also the fact that the rear wheel is almost fully enclosed by the air boxes, but I can't see the "parachute" affecting high speed handling. All scooters/cycles with the rider uncovered are essentially "pieces of plywood" aerodynamically at very high speeds compared to aerodynamic racing cars and yet Grand Prix and World Superbike bikes handle corners well at speeds over 150mph.

What I was daydreaming about would be some kind of hole(s) in the "parachute" with ducting to let the trapped air out the sides/bottom/back/or passenger section of the scooter. I think the biggest benefit would be gas mileage, I don't think many people want to ride the Maj at over 100mph, but I notice a major drop in gas mileage between about 55 and 75mph.

Another daydream would be to have a switchable duct for the air going through the radiator, like some Gold Wings have - it could exit out the back of the scooter as it does now in hot weather, and aimed at the rider's torso in cold weather.

kb6zmj,

No offense intended whatsoever, but when I read the post in question, it wasn't clear to me whether your purpose was to simply transport the drink or make it accessible for drinking while underway. I too am a safety advocate and don't encourage anything on two wheels that is even remotely houligan, and I do it by example and by what I say online or in person. I also remember that our readers here have not necessarily had the advantages of the MSF courses or the experience that many years of riding gives one. SO, having said all that, my point was just to point that out, not make you out to be a houligan. As a safety minded person, I would think you would want that clarified. You would not want one of your students to read one of your posts online and get the wrong idea would you? If I misinterpreted what you said, then they could too. So, as I said, no offense intended, but I wanted what you were saying to be clear and to point out the negative safety aspect of drinking ANYTHING from a cup while in motion on two wheels.
Enough said on that subject, let's get on to the venting aspect of the high pressure area inside the bike's cowling...have you looked at what the Burgy does in that regard??? I have a strong suspicion that to effectively reduce that high pressure area, it is going to take more vent area than those simulated vents will provide. And you already pointed out that the location might be a problem in winter riding, venting cold air precisely where you really don't want it-on the hands. When you pulled the cover around the gas tank filler, was there any way to duct some of the excess back out, say even under the bike????

Hi KB,

Yeah, I can believe that about the stats being biased toward sportbike riders and that we arent even on the radar...oh yeah, that is easily believable. I think in some ways that is a good thing, as a class, we may have better odds of riding many years with no major mishaps, particularly given our constant safety focus. Most sportbike riders that I know ride with no protective gear, do really houligan kinds of things when they do ride and generally tempt fate with their riding style and their cavalier attitude towards safety. So yeah, I expect many of the military guys who ride the sport bikes are at least a little like the ones I know...and the stats support that.
But getting to the main point of the post...I too am leary of hacking up the tupperware just to test an idea that might be a total flop and then have to go buy more body panels to replace it. Not a well considered plan...and due to the statistically low accident rate of these bikes, the chances of finding good usable body panels cheap to experiment with is going to be slim to none. But who knows, you might stumble across one somewhere cheap...but I bet if you do, you'll have to snatch it up quick if you want to get it.

Based on:

6) Other engine features
Other engine-related features include (1) a radiator positioned under the foot space to make effective use of the cooling effect of the running air flow, (2) an engine oil capacity of 1800cc for minimized oil deterioration (vs. 1400cc on the existing Majesty), (3) a side drain bolt for easier maintenance, (4) automatic decompression for great starting performance and (5) an air induction system and catalytic converter for outstanding environment friendliness to clear EU2 emissions standards.

Click to expand...

from http://www.yamaha-motor.co.jp/global/ne ... jesty.html

The lower section of the fairing houses the radiator which benefits from the air-flow produces by the shape of the concave section behind the front wheel. Trapping the air to force it through is how our scoot manages to dissipate engine heat without actually showing a radiator. If you look at most current sport bikes, they have the same configuration. There is a fan and coolant tank very near to the same area.

As for the large body work ... it is give and take. Wind protection ... or not? Take off the fairings and you might have a slight bit of advantage at certain speeds and the benefit of less weight, but you will not have an aerodynamic advantage at higher speeds unless you cut the windshield down to just below the level you could tuck to at high speeds ... like the high-speed sport-bikes do. The Majesty has much better wind protection than my FZ1 at speeds between 50-100, but after that it is much more comfortable to tuck down behind the small windshield ... not as easy to do on a scoot.

Compare nearly any vehicle that does not have an over-drive system with boat loads of torque and you will see the same pattern of better fuel economy at 55 mph vs. 75 mph. (and maybe even then!)

The Majesty is not perfect, but it is certainly an excellent design within its cost and technology parameters. If you removed all the fairings and made it fugly like the Ruckus, I suspect you would see even lower mpgs at highway speeds, not to mention the discomfort level.

As for the original topic of parachute effect, this not an issue at all if you wear proper riding gear which is, by its protective properties, more rigid than a cotton shirt or loose fitting jacket. When I ride the Majesty with my best gear I am never affected by the wind. The few times I have ridden with casual clothes, I do occassionally have my shirt puffing up like the Pillsbury Dough Boy ... depending on which way the wind is blowing.

To me, its a non-issue ... if you are riding highway speeds you should always have the proper gear which eliminates the parachute effect from bothering ... if you are riding slow there is no parachute effect from the lack of wind speed.

Scoot on!

Heh, heh, this is the most off the track I have ever seen a thread get :wink:
Since I started it:
- the parachute effect has nothing to do with your clothing acting
as a parachute
- it has to do with the fact that the front end of the Majesty is designed
to look like the front end of a sportbike, most of which is phoney - the
radiator opening is TINY, so the rest of the front-end acts as a very
un-aerodynamic parachute. Sportbikes with much bigger engines
need front ends that look like the Majesty's as they have much
bigger radiators, air/oil oil coolers, and; usually, front exiting headers
that need cooling off. They also usually have side mounted fairing
ducts that let all that air that is trapped by the front end escape, this
making them much more aerodynamic.
- if you count every single phoney air duct on the front of the Maj
AND by the handgrips I think it wins the "phoney air duct contest"
hands-down. :lol: