One for Hobot, it has wings!

I wonder what that was supposed to do ?

acotrel said:

I wonder what that was supposed to do ?

Click to expand...

We all know what they hoped it would do.

I guess we're all agreed on what it really would do.

Well he was a Dr of mathematics... R. Freeth.
I guess that modern computational functions would allow aero devices to function [Sidewinder tech, perhaps] just as all the current electronic stability controls do, except more pro-actively.

The evolution through to this ,





and then the ' slight Laugh ( by Britten ) when Cathcart queried the foot fairings , indactes someone knew something .




Britten pictures here .http://whotalking.com/picasa/Britten

This is the entry in Wikipedia for Rodger Freeth, who developed that bike with wings:

Rodger Freeth, Ph.D., (11 November 1950[1] – 18 September 1993) was a New Zealand motor sport competitor.

He held a Ph.D. in Physics and had a distinguished academic and motorsport career. His first love was motorcycles and whilst he was still at university he built a radical Yamaha TZ750A with an aerofoil. As a result the controlling body (New Zealand Auto-Cycle Union) banned the use of aerodynamic aids in motorcycle racing. He won the Arai 500[2] endurance race at Mount Panorama Circuit, Bathurst, Australia in 1982 and 1985, as well as NZ titles on NZ-built McIntosh Suzukis.

He later became one of New Zealand's best known rally co-drivers, first with Neil Allport and then with Peter "Possum" Bourne. As a driver he also won TraNZam titles in his V8 Starlet.

Freeth died in 1993 as a result of injuries received in an accident on the first day of the World Championship event Rally Australia co-driving for Possum Bourne.[3][4][5]

The accident that killed him was apparently a freak accident; the car crashed, and he was crushed by his seatbelt because of the way that the car impacted. Ironically his driver, Possum Bourne, (who maintained tne number plate Rodge (or a derivation of that) on his competition car) was also killed in a freak accident while driving up a hill climb route in a non rally car; someone came racing down and collected him; apparently he might have survived if he had been in his rally car.

Freeth is once removed from a Norton connection; as Wikidea says, he rode McIntosh Suzukis; McIntosh is the builder of Manx Nortons now.

Might be a bit of bother , if it did a wheelie at 160 mph . :?

I would think that the purpose of those wings would be to create downforce and therefore
if the bike were able to do a 160 mph. wheelie , the whole project could be considered a colossal failure.

Very telling about the fates of great people living it up.

The wings are definitely for down force and should work an advantage til the rest of the teams caught on so just banned so they didn't have to. At speed should stifle wheelies both straight ahead and when leaned on the extra rear traction developed. Dust Bins were banned too.

Straight steering gives Peel enough rear grip to wheelie sideways, up to a point then more power just loosens rear so would be neat to have help holding it down. The front is weirder though but its aero effects only showed up in Peel leans where eddies off the sliders added and subtracted to ground effects of pinching air in narrow angle to road surface. I think fixed wings would mess with gusts so would want active vanes on Peel, definitely with the side rig on.

Come put ya's minds to it how could air flow be tapped to both press rear down and keep it from wanting to pass ahead of rider... I've though up one solution to try.

Btw i am putting on my fathers WWII trench art aircraft made out of shells and bullets

Seems like the resultant down force from the wing would work against the cornering capacity (ex. traction).

A closer inspection reveals that the downforces were directed to the wheels [unsprung],so not squashing the suspended chassis. Surely if a missile can be computer controlled to provide effective responses at Mach 3+ speeds then an active motorcycle mounted system is feasible?
Note also: the Britten went faster when covered with a 'dustbin' fairing - for its landspeed record runs.

Not distinguishing between sprung and unsprung down forces here, just additional down forces. In a turn, the tires can do only so much work and handle only so much energy, and then they slide.

Great for braking straight line and maybe initiation of a turn but during the turn, presumably with enough speed to result in significant down force, it would work against you.

My hunch is that the big benefit is hauling the bike down from high speeds without locking up the brakes. Anybody have insight to this bike. I know Tony Foal has quite a bit to say about aerodynamics but I am not going to look it up now.

Well, cars have been using downforce to corner quicker for decades now, so why not bikes?

Cars - force normal to friction surface
Motorcycles - force at angle to friction surface (when turning).

Think in terms of a vector diagram with a bike leaned over. So say at 45 degrees half the force is contributing to friction while half the force is trying to push (slide) you off into the weeds.

I don't know, I would have to draw it out and see if one would be gaining anything while in a turn.

But the pic shows 0` angle of downforce to tyre footprint, pinning contact patch - similar to aircraft in banked turn?

J.A.W. said:

But the pic shows 0` angle of downforce to tyre footprint, pinning contact patch - similar to aircraft in banked turn?

Click to expand...

Then I am not sure what picture you are looking at. The bike with the wings in this thread has a horizontal and vertical component with respect to the plane surface of the roadway. You really need to break it down to a vector diagram. Just saying. Yes, there is an increase in force normal to the pavement (working for you) but there's also an increase in force tangetial to the pavement (working against you). Not an issue with four wheel vehicles as stated earlier as the force is always normal to the pavement (helps you).

Have a look at something like Tony Foale or John Bradley where I am certain they have illustrated this.

Maybe it would help keeping the front wheel down under high speed drives out of corners? Need that front wheel to steer - don't ya.

The old saying goes - 1,000 words are worth one picture, or maybe two with annotation:
From "Motorcycle Handling and Chasis Design the art and science" by Tony Foale

I wonder if ol` Tony ever rode a TZ 750? Let alone had similar empirical experience to compare his 'book learnin' to?
It does seem self-evident that when banked over, there is a contest between forces that accentuate tyre grip & reduce it, & losing it is more problematic.

It's a "free body diagram". This is first year college statics. It goes well beyond "ol Tony" and has squat to do with TZ 750's