Experiment: smooth wheel discs tested A-B-A - 4.6% mpg improvement @ 65 mph

[basslover911]

Originally Posted by NeilBlanchard

Hi,

Transparent covers would show the dirt from the inside, as well as the outside dirt.

I was actually thinking of doing this (that way the asthetics of my rim wouldnt be compromised) - just like the mercedes concept cars.

The "dirt" from the inside would be easily fixed by low dust brake pads... but about the outside hmmm

Do you really think it would be THAT bad? (MY new rims are black so I dont think it would show too much, plus I was my car once a week).

?

[JackL]

I'm wondering if anyone has done, or has heard of doing this, on motorcycle tires? Completely covering the spokes. It seems like a spoked tire would create a lot of aerodynamic drag. Is this true?
I know I've seen this done on some competition bicycles such as in the Olympics. The one problem I see in the real world is cross-wind effect while riding. You might get blown all over the road.
Any thoughts or comments would be appreciated.

[i_am_socket]

Disc wheels on a bike = awesome in a straight line with no wind. What works for cross-wind? Take a look at what the top competitors are riding on at Ironman World Championships in Kona, HI.

Essentially, a disc would double your side facing surface area making it extra hazardous. What do bikes use during speed record attempts?

[brucey]

I wanna test this out with my stock wheels/taped over. But theres no place nearby thats flat and straight enough where I can achieve more than 45 mph. It would be a very minor change best case scenario at those speeds. Damn these mountains sometimes.

[brucey]

And so I did test it out! Pleased with the results:

AB AB With normal wheels:
29.5 28.39 29.7 29.2

AB AB With smooth
29.8 30.6 30.6 30.3

AB Without:
30.6 29.6

AB With:
30.6 30.8

Average with normal: 29.483
Average with smooth: 30.45

3.5% gain.

Tested on roughly 1 mile roughly straight stretch of road. Scangauge was reset, cruise was set. 56 mph runs. Outside Temperature was 25 degrees or so the entire time and wind was calm.

[JackL]

Originally Posted by i_am_socket

Disc wheels on a bike = awesome in a straight line with no wind. What works for cross-wind? Take a look at what the top competitors are riding on at Ironman World Championships in Kona, HI.

Essentially, a disc would double your side facing surface area making it extra hazardous. What do bikes use during speed record attempts?

At Bonneville there are multiple categories for motocycles. The fastest ones have the wheels enclosed within the aerodynamic body of the vehicle. Second to that is enlosing the entire wheel in an aerodynamic shape. Again great for straight line but not much use for a dual-sport.
I guess I'll have to work most on aerodynamic efficiency & losing weight. One area I think I can improve is the shape of the panniers (luggage). Most have flat rectangular front surfaces. I'll experiment with various rounded fronts.

JackL

[brucey]

In case anyone was wondering how ridiculous I looked:

[lunarhighway]

I'm wondering if anyone has done, or has heard of doing this, on motorcycle tires?

not on motorcycle's but on cycles for time races and track races they're quite common. because these particular races are about pure speed the rider's position is more bended forward and the handlebar has an aditional central handle so that the riders arms are together in front of him... combined with a special drop shaped helmet this sure makes a difference in drag, however sidewinds are a problem with full wheels and in normal races where the riders are competeing side by side and are up agains the elements and the terrain i've never seen full wheels used.


here's a speed bike, most likely a carbonfiber frame with a lot of interestin aero shapes

[groar]

Originally Posted by brucey

In case anyone was wondering how ridiculous I looked:

People judging without trying to understand are ridiculous, not people doing things.

Denis.

[SVOboy]

Originally Posted by brucey

And so I did test it out! Pleased with the results:

AB AB With normal wheels:
29.5 28.39 29.7 29.2

AB AB With smooth
29.8 30.6 30.6 30.3

AB Without:
30.6 29.6

AB With:
30.6 30.8

Average with normal: 29.483
Average with smooth: 30.45

3.5% gain.

Tested on roughly 1 mile roughly straight stretch of road. Scangauge was reset, cruise was set. 56 mph runs. Outside Temperature was 25 degrees or so the entire time and wind was calm.

Can you show us a before picture of your wheels?