Project Slipster: Streamlining the Kawasaki Ninja 250 (WIP Thread)

[Rokeby]

Originally Posted by theycallmeebryan

Notice where his legs are... not sure my family jewels will approve of this riding position!

The designers may have taken a page from the whitewater canoeing book.
Canoeists unlike kayakers kneel in the the boat. The majority of their weight
is supported on their knees. Their butts are positioned on a mini-cell foam
pedestal seat glued in position. There is actually little weight on the pedestal
"seat."

Since we can't see into the fairing as pictured, this remains to be seen.

My question is where did the foot controls go? I don't see any evidence of
linkages back where the feet rest. Single proportional brake control on a
hand lever? Automatic transmission?

For the record, the majority of a white water canoe is filled with inflatable
flotation bags. You don't see white water canoers that often, but they are a
proud breed. Their mantra: "Half the paddle, twice the man."

A cheer from the North Adamston Divinity School: Go NADs!

[sendler]

Gave up?

[Logic]

Originally Posted by Christ

From the streamlined bike page:

The front wheel fairing has to go to. I was quite confident that it would work and not affect the steering to much.

It turned out to be very scary to ride even with as little as 3 beaufort (about 10mph) side wind I did not dare to go over 35mph. It is a pity I made a mould and all without ever testing with a cardboard model.

Now I am forced to change the design drastically

I guess that's a warning for ya!

Coincidentally, Googling "Slipster" places this page in the search results at #5.

The inner 'mudguard' in this pic is interesting aerodynamically:

The top ~3rd of your wheel is moving into the wind at 2X the road speed at TDC of the tire.
The motoGP motorbike racking crowd fairs that bit of wheel, and extends it down the shock to fair it, with a cam tail at the shock.


BUT they NEVER enclose half the wheel.
Anything wing-ish shaped that makes 'vertical lift' depending on wind direction ( side/cross wind + forward..!) is wucking fith your steering big time!! It will kill you!!!:

From my post on Endless-Sphere:

Making a bike aero inevitably turns it into a vertical wing.
Horizontal wings are great at making lift. Turn one 90 degrees...

The 'sideways lift' is not an insurmountable problem. You can lean into it.
But here's the nasty thing about wings: At a certain angle of attack (around 15 deg) they stall! Suddenly!! And your plane falls out of the air.
Vertical wing: There you are leaning into the crosswind /'lift' when the angle of the crosswind quietly changes to over 15 degrees.
Now you either fall in the direction you were leaning, or, if you're quick enough, you turn into the direction of the lean. That's either into traffic or off the road. And somewhere in all that chaos your vertical wing may start 'flying' again.

Back to that inner fairing:
Cut it so more of the rim is showing and some of the back off; fair in the shocks and it's a pretty aero NON WING mudguard.
That more vertical 'leading edge bit might be made more elliptical fairing-ish, 'Cam-Tailed' at the width of the tire, but I'd probably just cut it off at 2 O-clockish.

Aeo wheel spokes:
Only work if they can weather-cock, or it's the same dangerous story.
That would actually reduce the effects from cross-winds.
A tiny bit of spring to center would turn crosswinds into a tiny bit of thrust.

[freebeard]

That all may be true, but the bike has half the fully enclosed body removed. The front fender just minimizes turbulence inside the shell.

[Logic]

Originally Posted by freebeard

That all may be true, but the bike has half the fully enclosed body removed. The front fender just minimizes turbulence inside the shell.

I'm aware.
But vertical wings or anything even vaguely wingish has been banned form motorsport.
Killed a drag racer that was winning...till he wasn't for 1 eg

ie: You want safe before aero and that's as 'both' as it gets.

[freebeard]

Motorsport is notorious for mandating sub-optimal solutions. They preclude things like the Ford Probe V's skirted front fenders.

VW Vortex
Fender Skirts: Sometimes They Work, Other Times Not So Much... - VW Vortex
The Ford Probe IV concept car of the early eighties is now pretty much forgotten, but it still may be a harbinger of the future. The front skirts are "soft", being made of a flexible composite that allows the steering wheels, fitted with hard "helmet" inner fenders, to push them outwards when angled in turns.

Motor car History: Ford Probe 1980s Concept cars IV and V

Note that you can not access the open hatchback while the doors are open. ??