Vetterizing my 2013 Zero S ZF11.4

[sendler]

Originally Posted by Burton

@sendler
Are you confirming that if I did a 17 degree straight ice cream cone shape or a ideal shaped tail because of the rider gap the latter wouldn't be worth the effort?

A pure airfoil can be cd .07. A snow cone can be .16. Which is still way better than the .60 cd you are starting with
The total drag of the streamliner with a straight tail won't be twice as high as the vanishing value of an ideal airfoil because you will never achieve the drag number of the ideal with mirrors, heads and hands, egress gap/ side wind vent, lights, ect, sticking out anyway. Keep it simple and get it built or you will end up like so many grand designs I have seen presented here with it half way done and never finished.

[Burton]

Originally Posted by sendler

Keep it simple and get it built or you will end up like so many grand designs I have seen presented here with it half way done and never finished.

Have you been following my youtube channel long or you are you on Vetter's email list serv. I am spending every bit of spare time I have on this right now so it will get done 16 + hours on weekends and 2 to 3 hours on week days.

I didn't spend 12k for a bike and 2k for the Vetter fairing for it to simply sit in my garage and collect dust ^_^

I was just curious to know if it would be worth it to even build the ideal shaped tail vs a straight one. I am going to do the straight one anyway given it is the fastest and it would be nice to use it to compare with other modifications later. =D

As for headlights and such, I plan on making everything flush with the cowl / tail via port holes covered in lexan like vetter does his headlights. I have a JW Speaker 8700 and two 6050's coming in Wednesday to put on the front. Haven't decided on blinkers yet but they will be LED for sure.

@Grant-53
Are those angles for motorcycles as well as cars? Should I make an effort to flatten out the bottom of the bike and cover the top half of both tires with a wind deflecting fairing? I think the Vetter cowl covers the front pretty well.

[Grant-53]

These angles are for two wheel vehicles with a fair amount of ground clearance. The flat bottom template is primarily on cars. That's the simple version as far as I can tell. Fred Hayes uses an Aerotech Bonneville style low tail, but the word from fellow riders is the higher tails are more stable. We have been looking to get low drag and stable handling which includes some down force on the front. The Vetter front is a proven, if expensive, piece. Try to make the whole package smooth and flush, start with the rear wheel since it will be more exposed.

[Burton]

Vetter and I are finalizing the placement of key fairings via email today so I will have a better idea where stuff needs to be designed.

I have been looking at the strip built canoe technique specifically in relation to using foam and making recumbent shells. I think this technique would lend itself well to making the tail section.

Now I just need to identify costs associated with going this route versus another. Most people are using a router, a fixed saw of some sort (table or other), and a plotter. I don't have either but I think I can get away with using a wire cutter with a jig for the strips and a straight one for cutting the strips from the large sheets.

As for the plotter I could index the drawings and print them on 11x8.5 pieces of paper and tape them together. I am also going to have to redownload sketchup so I can make the required large plots (assuming it is capable of this if not I will simply use illustrator and math).

But I likely have to wait as I need the rear seat cowl as a starting point and I need to switch focus to getting the bike registered which is going to require mounting lights and some other items I must fabricate. In the mean time I can collect materials like the fiberglass, epoxy resin, tools to apply them, etc.

I also need to figure out my license plate solution on the 'ideal' tail. On the default tail it is going behind the head rest, but on the ideal tail it cannot be there as there will be fiberglass blocking it If I did the ideal shape and a Kamm tail on it I could easily mount the license plate. But if I did a point at the rear I imagine I would have to cut into said point like others I have seen do. I don't think I am allowed to make a plexiglass cover for the license plate to fill in the cut gap in Virginia / MD / DC.


@Grant-53

I haven't done the math yet but it seems the tail would be extremely long using the 4 percent / 7~8 percent grades, or do you only keep these grades till you reach the ideal length? In my case, given the width this would be 107cm.

[PeterS]

Originally Posted by elhigh

The 2014 calls out a range of 70 at 70 on real-world highway runs, it should be very interesting to see what streamlining does for you. It should make a big dent in your current draw while cruising, but you might experience a slight degradation of range due to the added weight.

Unless you're cutting the fat by pulling original cladding. I haven't dug deep into your blog yet. Maybe you'll mention it there.

On the contrary , your range will improve markedly unless you spend all your time climbing steep hills at low speed.

[PeterS]

A question on the Kamm tail ending .

I assume it should be a sharp ending ( unlike Allert's Velomobiel ) but would sharp with a flat or concave end be better or a protruding body section with a thin edge?

[Grant-53]

On a sailplane, the fuselage continues to a point. On your bike we are looking at a Kamm tail about 5" wide and maybe 24" +/- top to bottom. You would likely have three bulkheads including the end panels. By dividing the perimeters of each bulkheads into sections you can determine the dimensions of the skin pieces.

I use cardboard from cereal boxes to make 1/4 scale mockups. Skin material can be made from wire hex mesh glued between layers of .005" tarp plastic.

[bschloop]

I would highly recommend using the strip built canoe method with foam for your tail. This is what I did. it was much easier, and resulted in a lighter and stronger tail than just fiberglass. It was also easier to build than trying to make a mold for one tail.

[Burton]

Is it just me or does sketchup really suck for this type of thing? Back when I was pursuing an engineering degree I had a chance to use EE and it kicked ass compared to sketchup for this easy task.

I didn't feel like re-installing my 3dsmax copy given how huge it is but I have a feeling even it would have been easier to use >_<

I guess if I felt like blowing $500 I could then import a dwg from illustrator into sketchup but it isn't worth it. I think when I go to print this project I am doing it through illustrator and scaling it as needed.

All that said the below has a 4 degree down angle from top and 8 degree from bottom. There are really two bulkheads here, the seat and the lower which will likely be intersected by the rear tire / swing-arm etc. No Kamm shown and I was thinking I might just Kamm the head rest enough to fit my license plate vertically near the rear.

Thoughts? Oh if you can't tell the top profile has the ideal shape. The ribs colored on right are accurate and properly scaled for the degrees indicated, the sketchup stuff is relatively close.

FirstTailMockup

[PeterS]

I do recommend the canoe strip plank method of construction , if only for your plug. The strips have a wonderful way of lying in a fair curve without any effort from you.