Why a Helix?

It has the right power

I have come to the conclusion that it takes somewhere between 10 and 20 horsepower to propel a person down the road at posted speeds, in real highway conditions.

Further, it appears that if streamlined, fantastic gains in mileage come from using 20 hp or less.

View the work of MV8 Steve in streamlining a Helix

Look around: What vehicles have around 10 to 20 horsepower and are freeway legal?

Among those is Yamaha's 220cc Serow with 22 hp. My Serow gets between 57 and 66 mpg, ridden at real city-freeway conditions. Obviously, it has the enough power to take a person over Independence Pass. Pretty good.

My Helix gets 58 to 69 mpg, ridden the same way. I can find no official horsepower listing for the Helix but the Chinese copy of it has 18 hp, so it is probably safe to use this number.

Both these bikes will take us anywhere we want to go.

I choose the scooter because it is easier to get on and off when it is streamlined.

Son, Zak Vetter on Independence Pass on a Serow
The Helix has the right power... not too much... not too little

The Helix will respond to streamlining

The Helix will be easy to get on and off when streamlined

It is my observation that streamlining on vehicles with more horsepower will only allow them to go faster. Big horsepower engines do not run efficiently at the 10 hp range. Look at dyno charts.

It looks like a 95 cu in Harley - in the 10 hp range - is less than idle.

Chart from American Rider Dec 2007

Big engines do not operate usefully in the 10 hp range.
This informal explanation to visiting instructors from the University of South Australia, Rich and Jan Coker, as to why a scooter offers the best starting point for streamlining and fuel economy
This page updated June 17, 2008

updated April 13, 09