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-   -   Vetterizing my 2013 Zero S ZF11.4 (

Burton 05-10-2014 10:50 PM

Vetterizing my 2013 Zero S ZF11.4
I figured I should start a thread on here so people can ask questions and get updates. For a couple weeks now I have been posting content to my blog, youtube, and flickr accounts documenting the stuff I am doing to the bike. This week was more exciting because I started to make sub frame mock ups for the bike so I figured I would post up a thread.

Blog: Call Me Burton | Ventures into permaculture, electric vehicles, streamlining, motorcycles, preparedness, homesteading, and learning.
youtube: ( zero specific play list )

I am waiting for the last video I shot today to render on youtube before publishing my mostly weekly update on my blog. I plan on doing a lot more tomorrow to get the seat pan created in hardboard and on the bike.

I do have a question while I am at it. From the widest point in the profile of the bike, if I draw a straight 17 degree line to the tip of the tail will there be early separation or will the wind follow the profile?

I have drawings overlaid on Vetter's ride to better illustrate what I am talking about if there is confusion in my question. The third or second image in the group of 3 is what I am thinking but doing it along the 17 degree line versus the nice smooth curve.

Also does anyone know of a way to make complex curves like this easier than using composite materials and molds?

Burton 05-11-2014 07:48 PM

Got wood mockup on bike today and realized I made some mistakes, as normal.

I didn't get a chance to measure the angle of the straight section for reference since it was an on the fly decision. But I do have a cardboard template of the 'ideal' shape for my tail now. I just have to figure out the easiest way to make it.

NachtRitter 05-11-2014 09:57 PM

Looking forward to seeing where you go with this. Pretty cool to see an aero shell on a serious e-motorcycle.

sendler 05-12-2014 06:30 AM

Here are a couple great posts comparing a pure aero tail fairing to various straight sided and truncated shapes.

elhigh 05-12-2014 08:26 AM

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.

Grant-53 05-12-2014 10:08 AM

The time tested methods of making airframes is rib and skin. Bulkheads are of plywood or aluminum. Skins are doped cloth, sheet metal, or thin plastic.

Burton 05-12-2014 11:16 AM


Originally Posted by sendler (Post 424076)
Here are a couple great posts comparing a pure aero tail fairing to various straight sided and truncated shapes.

Ok now my head is spinning. So basically to do a straight tail of say 17 degrees I need to make the curved section before the tail, in this case at the seating cowl, for it to attach properly and even then it will have double the drag of a nicely arched 'ideal shape' tail of same length.

The good news is Kamm tail id ok if that curve is there.

The issue then is the gap. Do you recondition the air flow by lipping it up and out before the gap, do you use air curtains, or just leave it be to ensure reattachment at the seat/rear. Also what about the head rest, currently where the license plat goes on Vetter's design. It seems it would be better to extend it out into the tail and go with a proper Kamm tail.

The issue then for me is fabrication. Vetter uses sheets of milk carton paper to skin his bike since it is cheap and easy to repair which is why the bikes profile has a straight tail of 11 degrees. To do a proper tail I would need to bring back my model airplane skills and skin it up that way or go with full composite materials.

There is a good chance I might end up making two tails, one with the ideal shape and Kamm and the other to Vetter's spect with a little modification to shorten the tail. But it am having a hard time thinking they would produce radically different results given the open cockpit.

This bike was previously used for racing so everything not essential has been removed. This is a 2013 S 11.4 but I have been told it is lighter than the 2014 SR and faster, much faster. that stated I will likely be adding chargers to this equation and those add a lot of weight, but without then I cannot tour on the bike.

The chargers will be easy to remove for my weekly commuting via highway at 65 to 75 mph 26 miles one way. Ultimately though I want to be able to ride this bike much farther.

I assume then the best course of action for the proper tail would be to find out the shape of the seat pan and recreate it in a graphing program decrementing it to figure out bulkheads first. This likely will not happen till June at the earliest as vetter only just finished the seat pan last week.

sendler 05-12-2014 02:09 PM


Originally Posted by Burton (Post 424097)
make the curved section before the tail,

The round section is the nose of the bike. Regarding flat versus complex curves, "Don't make it more trouble than it is worth". A true airfoil can have half the drag of an ice cream cone but with all of the other trade offs to practicality such as the rider gap, the difference will be much less in the end. Choose what you can easily build or you will get hung up on perfection and never finish anything.

Burton 05-12-2014 03:14 PM

For some reason I thought the seat pan would also need to be rounded off as the wind from the nose cone crosses the gap to contact it next, or your body.

Since I don't have the cowl installed yet I don't know what else I can do to this airflow to make it follow the tail better.

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?
What if air was better controlled over the gap with something like an air curtain or something to throw the air out wider before the gap?

Grant-53 05-12-2014 05:07 PM

Start with the bulkhead at your back. The side profile top angle is 4 degrees down and the bottom is 7-8 degrees up. The rear following ribs are usually elliptical and you can adjust the widths a bit to get a slight side curve. The head fairing could be a half cone roughly 10" dia. and 30" long. The gap between the front nose and the rear bulkhead could be filled with a panel or something stretchy such as Lycra. It has more to do with riding style than anything else. If you prefer the open cockpit you might try a small lip around the back end to the nose piece and put a radius on the forward edge of the main bulkhead.

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