Craig Vetter Challenge, 5/13/2011, ridealong

[Frank Lee]

IIRC the Vetter site said the Mrs. was going to judge the grocery bag requirement. I'm just not seeing it...

[redyaris]

...we shall see...in a week or so.

[low&slow]

Hi Guys, Fred Hayes did 128mpg on his diesel MC. It was definitely the day for the diesels.
I didn't stay for the 4 grocery bag test which actuallly my bike would have been able to hold ( large tankbag, saddlebags and large tailsection). Apparently Fred had some type of hanging bags that did hold the 4 grocery bags. His fuel tank was tiny , probably no more than 2 gallons capacity.
I may have gotten better mileage if the course really was 133 miles as I went the full distance but my odometer only indicated 126.2 with a few miles in addition to the course. I need to check the accuracy of my odometer.
For next year, I need to close up the gap between me and the tailsection, fair in my front wheel and install a longer, taller windscreen. Alan Smith lives fairly close by so I may pick his brain on how he did fender, windscreen and tailsection. My seat is pretty tall and I can lower myself a couple of inches with a thinner pad.

[redyaris]

Originally Posted by Frank Lee

Well then any bike with essentially no built-in storage could qualify right?

You were right, but not for long, the new rules have made that illegal... the vetter websit has pictures.

[redyaris]

Originally Posted by low&slow

Hi Guys, Fred Hayes did 128mpg on his diesel MC. It was definitely the day for the diesels.
I didn't stay for the 4 grocery bag test which actuallly my bike would have been able to hold ( large tankbag, saddlebags and large tailsection). Apparently Fred had some type of hanging bags that did hold the 4 grocery bags. His fuel tank was tiny , probably no more than 2 gallons capacity.
I may have gotten better mileage if the course really was 133 miles as I went the full distance but my odometer only indicated 126.2 with a few miles in addition to the course. I need to check the accuracy of my odometer.
For next year, I need to close up the gap between me and the tailsection, fair in my front wheel and install a longer, taller windscreen. Alan Smith lives fairly close by so I may pick his brain on how he did fender, windscreen and tailsection. My seat is pretty tall and I can lower myself a couple of inches with a thinner pad.

The tail section should be between 14" - 16" wide at the front [the same width as your hips] and taper at a rate of 1 in 6 [9.5 degrees] and I recoment that you make it 30" or 36" long. The rear end should be 4" wide. the height at the front should be around sholder height. aprox 24" - 30" tall. I will post some pictures of mine so you can have a better idea. In your picture the big tank bag should be the same height thoughout it's length or slope upward to the rear. The way you have yours is backward, with respect to aerodynamics. What you are trying to do in this tank area is fill it up as much as posible so that the depresion behind the windshield is as small as posible. The Idea is to only push the air out of the way once, so once it is out of the way keep it that way until the rear taper. The top should also taper at 1 in 6 from the horizontal, but if you have the same issue as my gs500 you will have to adjust this so the slop is 1/6 form the horazontal because the tail peace may sit at an angle on the bike... the shape and exit angle of the windsheild is critical make it round and exit angle as close to the air streem as posible.

[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

[redyaris]

low&slow
Looking good. I have a Honda VT500 with shaft drive that I have plans to aeromod. We could challenge each other to see who can get the best fuel economy for a 500 - 550cc shaft drive motorcycle. For us the holy grail would be 80mpg under vetter conditions. I suspect that 70mpg is achievable with basic aeromods and that 80mpg would be quit demanding to achieve. I have learned a lot from the work on the GS500 that will transfer to the VT500. What do you say?

[low&slow]

RedYaris, Thanks ! I'd definitely up for the challenge will try to post as I make improvements on my Vision. Thanks again for all your great suggestions and generosity in sharing your findings.
all the best, L&S