Bikes with wings?

[johnaachen]

Why don't bikes use wings to generate down force?

[mattikake]

Because they roll excessively in corners.

For ultimate lap time cars are fundamentally superior in many ways...

[Mazda Baiter]

Because you would find it very difficult to get the downwards force to push in the right direction of the tyres to the ground.

[E30M3SE]

johnaachen said:

Why don't bikes use wings to generate down force?

Some do.

[DangerousMike]

but wings on planes work with big roll angles, why is the same not true of downforce generating wings?

[Munter]

DangerousMike said:

but wings on planes work with big roll angles, why is the same not true of downforce generating wings?

My guess:
Wings on a plane are "pulling" in the direction the plane is turning towards. The wings on a bike would be doing the opposite.

[Scuffers]

also a bike's pitch is far from stable.

[DangerousMike]

it makes sense to me that pitch sensitivity would be a big problem with the bikes, as it is on cars, i just was unsure about how the roll angle was a problem.

[bernies]

They tried in the 70's...

http://www.motorcycletrader.co.nz/View/Article/Rod...

[LocoBlade]

On cars the downforce always pushes vertically downwards because the wings are always (give or take) horizontal, so adds downward pressure on the tyres making them grip the tarmac more, but doesn't add any additional undesirable side loading on the tyre, so when the car changes direction, the side force on the tyres (which it has to resist to make the car turn) is still proportional to its weight alone.

On a bike, the wings would lean with the bike meaning the force wouldnt always be downwards, as the force would always be in the direction perpendicular to the wing, i.e down the centre line of the bike when looking from the front/back. On the straight when you don't want drag inducing downforce slowing you down you'd have good downforce but at any lean angle, wings would add an undesirable horizontal force trying to push the tyres away from the direction you want them to go in. At 45 degrees lean you'd have "downforce" at 45 degrees to the tarmac, so equal amounts of downforce and "sideforce" pushing the bike away from the apex of the corner. This means although you'd have some additional downward force on the tyre which would in isolation make it grip more, you also add extra side load on the tyre pushing outwards which is counter productive.

Edited by LocoBlade on Monday 30th August 19:59

[kiteless]

Bikes don't need wings to fly:

http://www.youtube.com/watch?v=HRnFPgxj2BY

[cogitoergozoomo]

Couldn't you have a gyro wing that stays level as the bike leans? Kind of like the gyro cam they have?

[VladD]

If you had a gyro you'd have to think about where the wing was attached to the bike. If it was just behind the saddle, then during cornering the wing would just be trying to low side the bike as the downforce wouldn't be acting where you wanted it, i.e. on the tyre.

[dan tournay]

The only bikes I know with proper wings for down force are the ones that go in a straight line

http://www.dragbike.com/dbnews/anmviewer.asp?a=261...

Edited by dan tournay on Tuesday 31st August 15:16

[GT Kodiak]

Wings wouldn't work... A Rudder-esque system however...

[mchammer89]

cogitoergozoomo said:

Couldn't you have a gyro wing that stays level as the bike leans? Kind of like the gyro cam they have?

But wouldn't that make the bike lean more as you begin to corner? If you consider the bike pivoting about the contact patch, a wing generating downforce while the bike is leaning will push the bike into leaning much more.