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-   -   Any IHPVA racers or builders? (https://ecomodder.com/forum/showthread.php/any-ihpva-racers-builders-19091.html)

TFS 10-09-2011 06:00 AM

Any IHPVA racers or builders?
 
Has anyone built bikes for IHPVA races? We did several in college days. They were fun projects. (There are a few pics in my profile page).

Grant-53 03-12-2012 12:41 AM

Not yet, but would be game to try some time.

jjackstone 03-14-2012 03:56 AM

TFS,
I'm working on a build for Battle Mountain this fall. Hopefully will have time to complete it.
If you haven't already done so, you should post some of your old hpv photos at recumbents.... Everyone there loves to catch bits of the early hpv renaissance. Upright Mike would like the photo of the faired upright.

JJ

Grant-53 03-15-2012 04:56 PM

I have posted my fairing design photos on Photo Bucket under 'wgconnor'. The URL is Pictures by wgconnor - Photobucket Let me know if this brings up my three albums. These pics are mainly of fairings for street use up to 30 mph. An upright rider in the aero position has about the same frontal area as a recumbent according to the chart in Scientific American (p. 150 Dec. 1983). A fairing in the shape of a 4:1 body of rotation with a 25% kamm cut could be very competitative with a lower weight.

TFS 03-15-2012 05:56 PM

Quote:

Originally Posted by jjackstone (Post 293290)
TFS,
I'm working on a build for Battle Mountain this fall. Hopefully will have time to complete it.
If you haven't already done so, you should post some of your old hpv photos at recumbents.... Everyone there loves to catch bits of the early hpv renaissance. Upright Mike would like the photo of the faired upright.

JJ

I do have some, will do! I was on the CSU Fresno HPV team that raced ASME West races in 1983/4.

The year they had the ASME event at US Santa Barbara, our 10 speed with fairing got DQ'd! We were killing everyone in practice and the ref decided we didn't meet the criteria for building a vehicle. Sheesh! I argued that my materials text said "Engineers adapt energy and materials for what society needs." So, we adapted! It's engineering. Didnt work.

TFS 03-15-2012 06:02 PM

Quote:

Originally Posted by Grant-53 (Post 293652)
I have posted my fairing design photos on Photo Bucket under 'wgconnor'. The URL is Pictures by wgconnor - Photobucket Let me know if this brings up my three albums. These pics are mainly of fairings for street use up to 30 mph. An upright rider in the aero position has about the same frontal area as a recumbent according to the chart in Scientific American (p. 150 Dec. 1983). A fairing in the shape of a 4:1 body of rotation with a 25% kamm cut could be very competitative with a lower weight.

The pics look cool!

I remember that SA article. I know two of the authors, Kyle and Malewicki. They came to our ASME conference in 1985 and both tried out the bike with fairing in my sig photo.

I think you probably will approximate the drag of a recumbent with that design.

Our bike with fairing matched the CdA of a rider drafting another bike almost exactly-CdA reduced 50%.

I wrote about an 80 page paper on that fairing and the testing. I scanned it the other day. Of you want a PDF, email steve@stevebruhn.com and I will send you one.

Grant-53 03-16-2012 07:55 PM

The aero Jamis fairing boosted my comfortable cruise speed from 10 mph to 15 mph. No problem with crosswinds. It was put together with inexpensive pieces I had laying about. The gap between the fairing and the rider's shoulders can be reduced. The fairing would come to just below the knees. The next choice is between a two piece system and an envelop body. Since I aim for a streetable product, getting off and on is paramount.

TFS 03-16-2012 08:57 PM

If you want a short cut, I bought screens from this source-
Gustafsson Plastics

The pic in my sig has a screen from a Harley XR750 road fairing. It fit perfect and was thin, not too heavy. Plus the optics are very nice!

Grant-53 05-11-2012 01:01 AM

I have been researching the www. for bicycle aerodynamics and found a pdf for the 2009 Final Design Report from California State University Northridge on their entry in the ASME Human Powered Vehicale Challenge. It looks like your fairing was ahead of its time.

For lots of info on recumbent builds and racing log on to recumbents.com.

Grant-53 07-26-2012 02:30 PM

My latest touring fairing for the Jamis is a front only coroplast piece that gained 3 mph from 11 mph to 14 mpg at casual cruise effort.


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