motorcycle aero mods

[euromodder]

Originally Posted by Varn

I would stay away from any fairing that moved with the steering.

It's OK for small flyscreens, Buell or streetfighter-style, but a bigger fairing can certainly upset the steering in the wrong conditions.

[fidalgoman]

Go out to Vetters website and look around. You'll be amazed.

[low&slow]

I started working on the tailsection and my initial CAD testing indicated a noticeable improvement in drag reduction with no worse handling from side winds. I went to visit my new motorcycle streamlining guru Alan Smith to show him the work I've done on the front fender, windscreen, tailsection , lowered seat pad and rear wheel enclosure. He recommended I lower my windscreen to shoulder level and contour the side to better direct the airflowcloser to my body. He also recommended I round off the leading edge of the front fender, cover the fork legs and brake calipers, fair in the hand controls, reduce/ reposition the mirrors, reduce/ recontour/repalce the long stalked turn signals.
I wish the Vision was chaindrive instead of shaft drive so that I could gear it up. I'll try a larger rear tire after I wear the current one out.
The sidewind steering interference is noticeable but I'm adjusting to it. I live in a great area for testing as its always windy here in the Livermore Valley. A framemounted fariring would help a lot. I had a 57 MPG tankfill so things are looking up.
all the best L&S

[KamperBob]

Originally Posted by low&slow

L&S, great minds think alike. In recent days I prototyped a Q&D windshield for my bike too.

[Varn]

L&S
I think the back looks pretty good but ahhhh the front might use some updating, too many straight lines try a nice rounded spherical shape there. Be careful of that big flat windshield becoming resonant. Spherical is a good thing on a street bike, it works better in cross winds. Every edge trips the flow.

[low&slow]

KamperBob, good start and nice job!

Varn, Thaks and duly noted. I lowered and re-contoured the windscreen, still have to work on that flat face of the front fender.
all th best , L&S

[Grant-53]

Craig Vetter's website is a great place to start and July 22nd is a Gathering of Streamliners at Mid Ohio. Sport Rider magazine did some windtunnel tests in 2006. Check the website for older articles. The trick to stability on a 2 wheeler is rounded sides and some downforce. Definitely mount body work to the frame and NOT the steering gear. Start with a profile from a NACA wing form and invert for downforce. Use your bike width and height dimensions to generate ellipsoid shapes in a 3D spreadsheet graph. Keep the center of pressure behind the center of mass. For easy access when throwing your leg over the seat, have the rear section slide back on heavy duty drawer rollers. Reinforce the fairing for some crash protection at the front and sides particularly and consider an inertial reel lap belt.