The Search for Fuel Economy

Pages from a Designers' Notebook

This page updated June 29, 2008

Chap. 11: Finishing the tail
We know a tail is important for streamlining. We know that weight at the rear is very bad. Weight needs to be at the front for good handling. How will we make the tail light weight? It would be nice to make it removable. How will we attach it? Time to find out.
First some good news...
Carol took the Streamlined Helix to the grocery store and easily stowed away four bags of groceries.

64 mpg... parking up close... four bags of groceries...

Can it get much better?

Four bags full
Making a foam board tail
I have been riding without a complete tail for a week. Two tanks of fuel both gave me 69 mpg. I am anxious to finish the tail. It seems incomplete without it. This is still not made of final material... this is to figure out how to mount it and to do some more test riding.
A proper streamlined shape
I have devised a way to put the tail on and off with bungee cords. It weighs less than a pound, complete. Around town, I can leave it off for easy parking. On the road, it goes on for max fuel economy and high speed stability.

Perfect.

My son, Zak rode down the coast on the stock, red Helix. I rode the streamlined one. As usual, a 50 mph wind blew us down the 25 miles to River Inn and we had to fight our way back home to Carmel into the same wind. Hurricane Point is one of two local areas of terrifying and unpredictible winds, making this route a great place to test streamlining. I don't think there are any places so scarey. Compared to the previous foamboard tail, which was fine, this tail seemed to be a little better yet. I suspect that it is because this tail is lower, rounder and better streamlined.

We could see smoke and the road was closed ahead but did not realize that the devastating Big Sur fires had just begun. As I write, the fires are burning out of control, about 25 miles from our home.

That is fog, but Big Sur is burning (June 22, 2008) in the background
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Time to strip off the rest of the plastic

I always wondered what was under all that Helix plastic. It only took about 50 screws. I think I will leave the front fender liner in place if I can figure out how to hold it securely.

Now we can make the front bulkhead.
Hot melt and cardboard grabs the shape
Tracing it onto foamboard
You have seen all this before.
Cutting full size in plywood
Forming aluminum bulkhead
This makes my heart beat a little faster
I just had to prop the new bulkhead up to see how it fits. This is exciting stuff. Even better, it looks like mounting this forward bulkhead will be pretty easy. Stay tuned...

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This page updated June 29, 2008
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