This 1925 Seal three-wheeler is “the first of its kind”—and 1 of only 2 survivors

There’s a lot to be said for Mustangs, Corvettes, and muscle machines, including this: They’re everywhere. If you’re looking for something that isn’t, how ’bout a quirky three-wheeled vehicle that’s more motorcycle than car?

Offered at Bonhams’ Summer Sale, scheduled for July 2–4 in Stafford, U.K, is this rare 1925 SEAL 980cc Family Motorcycle. The name alone—a family motorcycle?—is a dead giveaway that this is unlike anything you’ve ever seen. Bonus: It comes directly from the U.K.’s National Motorcycle Museum Collection, which is made up of 1000 well-cared-for machines from 170 manufacturers.

The Bonhams auction is being held in conjunction with the International Classic Motorcycle Show.

The Seal, an acronym for Sociable Economical And Light, was produced by Seal Motors Ltd. in Hulme, Manchester, and was an early attempt to create an economic vehicle that could cheaply get the fam from A to B. Seal Motors called it “The first of its kind and still miles ahead. The comforts of a car at the cost of a motorcycle combination.”

“Comfort” is probably stretching it a bit, but Seal took the idea of a sidecar and turned it on its head. Rather than a bolted-on affair, the driver and passenger compartment was the main focus. The motorcycle itself didn’t even have a seat; it was just used for power—and to provide two of the vehicle’s three wheels. Plus, the detachable sheet-steel fairing kept the engine and gearbox free of dirt.

Although early models had tiller steering and were powered by a 770cc JAP V-twin engine with belt drive and Sturmey Archer hub gear, later models (like this one) had a steering wheel and more power. This right-hand drive Seal has a 980cc JAP engine, three-speed countershaft gearbox, and chain final drive. According to Bonhams, Seal made two-, three- and four-seat versions; this one is can accommodate two adults and two small children.

Weighing only 5cwt (that’s 560 pounds), the lightweight vehicle offered 50–60 miles per gallon of petrol, and the road tax was a meager £4 per year. Seal was so confident of its product that advertising asked, “Who would ride on a saddle exposed to all weather and road mud? No one, only those who do not know the Seal.”

It seems that not enough buyers found the Seal to their liking, however. Bonhams says although there is no record of how many were built, this is one of only two still known to survive.

The motorcycle hybrid comes with an old-style logbook, issued in 1946, along with assorted correspondence and some photocopied in-period literature. The logbook shows that the vehicle was previously fitted with a different JAP engine; the current engine dates from 1922.

Presale estimate is £16,000–£20,000 ($22,000–$28,000).

Bonhams does not indicate if the Seal (frame 780 / engine KTC/E 2859) is in running condition, but its registration (MB 9768) has lapsed. The three-wheeler looks to be in decent shape overall, so let’s hope it doesn’t take much to put it back on the road. Folks really need to see this thing—whether it remains in the U.K. or finds a new home in the U.S.