As motorcycle riders age, many trade the sportiness of two wheels for the stability of three.
That's producing a boom in sales of motorized trikes, and naturally one of the most popular is a Harley-Davidson.
Harley's Tri Glide Ultra, starting at just under $33,000, is large, luxurious and loaded with the comforts of a big-bore bagger.
Powered by Harley's fuel-injected 103-cubic-inch twin-cam engine, the Trike produces 106 foot-pounds of torque, sucks fuel at the rate of 38 mpg, and roars like a road warrior.
The lengthy list of standard equipment includes a rider-to-passenger intercom; an information screen with readouts for air temperature, engine temperature and oil pressure; full audio and navigation systems; self-cancelling turn signals; and plug-ins for everything from iPods to iPhones to cold weather clothing.
It even has keyless ignition and almost 7 cubic feet of storage space in the locking trunk and top box.
Like most big Harleys, it comes standard with cruise control. Also helpful for long-haul riding are the passenger backrest, wide footboards and sturdy hand-rails.
And like most big Harleys, it's big – almost 9 feet long, and over 1,200 pounds – but rides low, with a 28-inch seat height.
People of a certain age may dismiss three-wheelers, remembering them as the vehicles of choice for the meter maid or the ice cream man.
The Tri Glide (joined now by the low-slung, less-expensive Freewheeler) is the fourth top-selling model in the Harley 36-model family, behind the two Street Glides and the Ultra Limited.
It is particularly popular among older riders who want the big Harley feel without the heft and weight – and with the added stability of the triangle wheelbase.
That's an important fact for Harley's future. As the baby boomers who make up Harley's principal buyers age, more of them may start thinking three wheels instead of two.
On the road, the Tri Glide Ultra is strong and steady – a little balky around town, but smooth on the highway. The "dual" rear foot brake also engages the front brake, when applied, which makes slowing this big boy pretty easy.
It even has its own reverse gear, which helps with parking. A foot-operated parking brake keeps it steady when it's docked at the curb.
But this is one wide ride. That means no lane splitting, and forget sneaking into that slender parking space that's too small for a car. This is a car. There's also none of the leaning into the curves that makes motorcycling feel so much like flying.
Turning the Tri Glide involves more muscle than body English – a steering damper helps – and in tight turns can be more like work than play.
Despite that, this is a real Harley, and comes loaded with the company's traditional heavy chrome and richly hued bodywork.
As Abraham Lincoln is reported to have said: "People who like this sort of thing will find this the sort of thing they like."