Streamlined motorcycles

[TFS]

Since a motorcycle has wheels, the air pumping in to the body of a streamliner is far more important than ground effects.
Years ago one of the engineers that did the aerodynamics for the Vector HPV (which held the speed record for a few years), presented a paper at an IHPVA conference that showed about 1/3 of their total drag was due to air coming into the fairing and ground disturbance was negligible.
The point was that designing to take account for ground effects is a waste of time. Focus on internal airflow (for full streamliners).

[TFS]

Originally Posted by BHarvey

I was thinking of a two piece full faring that joins by the riders legs, with the rear section of the fairing on rails so it could be slid rearward and expose the entire sides of the rider and be locked in that position for city use.

Then slide it forward for highway use to get the full effect........

Honda R&D made one like that for the Vetter rally. I tried to copy the idea for a 10-speed bicycle. I did wind tunnel testing and I could not get the rear half of the fairing to work. Drag went up. We ended up running a front fairing only.

[TXwaterdog]

http://www.youtube.com/watch?v=TE7lmnl-NlM&t=45s

[/QUOTE]


Checkout that link for a ground up build of an enclosed recumbent electric assisted bicycle. He pedals to charge the batteries and the electric hubs actually drive the bike. He lays it all out and does a really good job at building it light enough to be worth it. You could probably transfer 90% of his design to your bike build.

[TXwaterdog]

Coolest thing I've seen in a while!

http://www.youtube.com/watch?v=Z0m-cUxMcJw

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[NeilBlanchard]

Here's the test ride video:

[Grant-53]

I would be interested in some pics of your attempted tail piece. I'll try to post mine on photobucket. I suspect something like the Oscar Egg Rocket will work if the fit to the rider is right. My front fairings attach to the frame and go from just below the knee to the shoulder. Don't have a wind tunnel, just a steep hill, speedometer, and a ball of yarn.

[TFS]

Originally Posted by Grant-53

I would be interested in some pics of your attempted tail piece. I'll try to post mine on photobucket. I suspect something like the Oscar Egg Rocket will work if the fit to the rider is right. My front fairings attach to the frame and go from just below the knee to the shoulder. Don't have a wind tunnel, just a steep hill, speedometer, and a ball of yarn.

Grant-Our tailpiece didn't get past the wind tunnel stage. We had a GI Joe on a 10-speed model I made from welding rod to scale, and used the fluids lab at Fresno State. The fairings we made were crude, mostly paper, put we got about what we expected out of the front piece. The rear just didn't work. I tried lots of tape and paper combinations to understand it better, but they all just added drag.

You might do just fine with one on a real bike if you get the right fit and separation from the front is minimized.

We just concluded that for a partial fairing, the separation already creates the drag and the tail piece is too far back on the shape to prevent it. Once you get separation, you don't really have a streamliner anymore.

I would still like to see someone make one work! Send pics!

BTW- coast down testing can tell you a lot if you do it right and repeat enough runs.

[junkyard]

Nice design, looks like tron. I want one