reclaimer said:

I always assumed reducing the rear wheel rpms to a suitable level would make it horribly slow. ... Is the goal to get the jack shaft to turn near the same rpms a correct sized wheel would?

Suitable wheel RPM for a small wheel (pocket bike or scooter) is MUCH higher than suitable RPM for a 26 inch diameter tire. Think if it this way. When a 10 inch diameter tire makes one complete rotation, the wheel moves forward 31.4 inches (by the circumference.) When a 26 inch tire makes one complete revolution, it will move forward by

* it's* circumference, which is 81.6 inches! Both tires have made one revolution, but, the 26 inch tire has gone 2.6 times further... This means that a 10 inch (outer) diameter tire must spin 2.6 times

*faster* than a 26 inch tire, just to travel at the same speed.

for a 26 inch wheel to be traveling at 40 mph, it needs to be spinning at approximately 517 RPM. If an engine is running at 7000 RPM, then, between the engine and the wheel, you need to reduce the RPM by a factor of about 13.5.

Since the Comet CVT actually INCREASES the output RPM at the high end, (by apx. 11 percent,) the output shaft is actually turning at about 7780 RPM at the high end.

So, to get the final wheel RPM, the total reduction between the Comet and the wheel, you need a total additional reduction of a bit over 15 (15.04)

Adding a jackshaft with an input sprocket with 48 teeth, (assuming an 11 tooth sprocket on the Comet,) an output sprocket with 14 teeth, and a 48 tooth sprocket on the wheel would result in a 14.96

__additional__ reduction. That 14.96 reduction, coupled with the .9 reduction of the comet at high rpms, results in a total reduction, engine to rear wheel of about 13.46, which, at 7000 RPM, would put your speed at a bit over 40 MPH.

Let me reiterate, though. On a bike, 40+ MPH is fast, but manageable. On a three-wheel bike, it verges on the dangerous. You can lean into a turn on a bicycle. You can't lean a trike into a turn. It is much more susceptible to flipping when you turn, especially an emergency turn.