How many more mpg you think i get in a full tuck compared to sitting upright? I've never done any testing on this but i was just curious if anyone has or knows the answer. I have a full fairing F model by the way.

Ermmmmm,
Its Going To Improve Aero''s . So It Would Do Some It, lol

Jay

Car data shows that going 90km/h instead of 110 uses 25% less fuel basically as the aerodynamic drag increases exponentially as your speed increases.

So I think a full tuck could result in a significant fuel saving at higher speeds but not much at 60km/h

Yup, air drag is related to speed diff. squared.
Double your speed, it's 4x the air drag.
That's why GS and most other bikes won't get to redline in top gear.
It might actually go faster in 5th gear compared to 6th gear. 

Any little gain at high speeds might make some difference in mileage.

yeah, you'd probally gain a little bit at high speeds for the reasons stated above, but you probally wouldn't notice much difference at the pump. Couldn't hurt though.

A taller windshield probally helps a little bit too as it'll smoothly divert the wind over you more without you being in a full tuck. I think some racers use them.

Quote from: MikeNW on May 18, 2007, 08:02:15 PM
Yup, air drag is related to speed diff. squared.
Double your speed, it's 4x the air drag.
That's why GS and most other bikes won't get to redline in top gear.
It might actually go faster in 5th gear compared to 6th gear. 

Any little gain at high speeds might make some difference in mileage.

It is actually cubed. You get 8x air drag from double speed.

A car with 125 hp can reach 125 mph.
To reach 250 mph you need 1000hp car.

A 1k hp, 1.5million dollar car

going by previous posts, you could likely see more MPG improvement by just reducing your normal speed by 10% and throttling more smoothly.

picking a more efficient route to work/play would likely help too. i mean less stop/go, more smooth throttle.

you could really get geeky and cut the frame and make it a fully faired recumbant.

i'm not a fan of the tucked postition myself, as some part of my 6'4" frame would get 'tucked' into a less than optimal position for comfort.

Here's an article that proves how much of an improvement aerodynamics can have on a bike.

http://www.suzukicycles.org/high_milage_suzuki.shtml

"It is actually cubed. You get 8x air drag from double speed."

You sure?  Now you got me looking in my old fluids books....     Which is not necessarily a bad thing!

Either way, it's a lot

BTW, many years ago, Car and Driver analyzed gas mileage, and found that the biggest mileage eater was making many stops and starts. 
Think about it- you use a lot of energy to get moving (K.E. = 1/2 m*V^2) then you come to a red light...  What happened to all of that energy? 
It was wasted as heat, using your brakes to stop.  Even if you coast down, friction eats the energy and it is lost.  Then you have to get the whole mass moving again. 
I find that NOT hurrying to the next light (keeping the bike or car in 2nd or 3rd and timing your ride to hit lights green) results in a large gain. 
Of course, not applicable in modern congested urban areas with lights every quarter mile. 

http://en.wikipedia.org/wiki/Drag_%28physics%29

Drag is related to velocity squared. 
Not quite cubed, but still increases greatly with speed increases

Ride safe!

I don't know how much it means in mileage, but I was playing with aerodynamic tuck last weekend.  I had the throttle lock on, so there was constant throttle input.  I could gain 3 mph at interstate speed by tucking tight behind my F-16 windscreen (even a little faster with my butt elevated slightly).

I need to do the same experiment without the tailbag on the bike.  The tailbag may have accounted for the better speed with my butt elevated (better airflow over the tailbag).

No elevated butt jokes, please

I'll try putting a pillow under my butt to see if I get better gas mileage!