Pterosail — the sailing trike

I think we were on a bicycle tour to Montreal when my friend Bruce had the idea of attaching sails to our bikes to make them go faster. Always the practical one, I chalked it up as another of his hare-brained schemes, like his vacuum-cleaner shoes.

All I can say now is Bruce was ahead of his time.

A retired attorney has developed a sail system that attaches to a trike and propels it along the highway. The rig is called the Pterosail, because it looks kind of like a pterodactyl. If you biked at RAGBRAI, you might have seen it. 

Not only does the jib-like sail propel a trike cyclist down the road, but the brakes convert wind energy into electricity that can be stored in a battery that powers a small assist motor. It's the same technology employed by hybrid cars.

Oh yeah. It has pedals too in case you're interested in pedaling, or if you strike headwinds.

The Pterosail website calls it the “next evolution in cross-country cycling.”

Stability of trikes

Retired attorney Phil MacTaggert of Illinois got the idea when he was checking out three-wheeled recumbents — trikes — in a Northern California bike shop. He was impressed by their stability and had the idea of attaching a sail.

The system he finally developed uses a mast and boom to support a jib that catches the wind out in front of the cyclist, who steers with one hand and tightens or loosens a line to the jib with the other.

MacTaggart was joined by his son, John, and friend, Chris Renders, both engineers, to fine-tune the Pterosail in the deserts of southern California and western Arizona in May. They've also ridden the Pterosails in Colorado, Illinois and Iowa.

Top speed

They learned that a single-seat Pterosail requires winds of about 8 to 10 mph to go without pedaling. In a stiff wind it can sail along at 40 mph.

The trike — two wheels in front — is stable and doesn't tip or leave the ground. Depending on wind direction, a passing vehicle can momentarily luff the sail.

The Quad City (Iowa) Business Journal says the mast is 12-foot-9 and boom is 6 feet long, making it legal for use on highways.

The Pterosail website has two videos of the rig in action and plenty of pictures. The design team is developing a third generation Pterosail which might be the one they bring to market. Look for them at this year's Interbike in Las Vegas.