Wednesday, November 21, 2018

Barber Museum brings a 1924 Sunbeam to light

Motorcycle of the 1920s on display in museum.
The 1924 Sunbeam Model 9 was a fast and desirable British motorcycle of its era.
I've made an effort to learn the rich (and complicated) history of Royal Enfield motorcycles but, while I admire other vintage motorcycles and their fascinating quirks, I don't know much about individual brands.

Yet another reason that my visit to the Barber Vintage Motorsports Museum in Birmingham, Ala. was so special.

You know what it's like. You see something interesting, do a little research, and end up falling down the rabbit hole. In this case, the object of my admiration was a 1924 Sunbeam Model 9 motorcycle.

Why? To tell you the truth, what caught my eye was the little tool case tucked, of all places, between the chain runs.

Tool box mounted very low on motorcycle.
Here's an interesting place to put the tool box.
What inspired that, I wondered? Did Sunbeam figure you'd be kneeling beside the bike trying to fix it? Was it an effort to get the weight down low for balance? Whatever the reason, it appeals to me.

The other feature I love is the tiny (really tiny!) pad on the rear fender, which would have made no passenger happy. Undoubtedly it was there so the rider could slide his bum back and lean across the tank in pursuit of those extra few miles per hour.

Tiny seat pad on rear fender of motorcycle.
Pad was for speed, not for a pillion rider. No rear foot pegs are fitted.
While these aspects were visually intriguing, the 1924 Sunbeam Model 9 was much more significant in motorcycle history.

The bare specifications are simple enough.

British, single-cylinder, 499cc, overhead-valve pushrod motor. Three-speed hand shift, front girder forks, rigid rear. Top speed 75 mph. The museum's Sunbeam "is believed to be the earliest surviving example of this model." But there is much more.

Motorcycle Trader magazine wrote in 2013:

"Of all the British motorcycle manufacturers during the 1920s, Sunbeam reigned supreme as the purveyor of quality, single-cylinder motorcycles. Built by craftsmen dedicated to attention to detail, Sunbeams exhibited the finest workmanship and finish of all singles built in England. When the Model 9 Sunbeam was released in 1924, motorcycles of its class were still priced in guineas (one pound, one shilling), not pounds, reflecting their role as a gentleman’s conveyance.

Flat tank of motorcycle is labelled "The Sunbeam."
"The Sunbeam" expresses the bespoke quality intended for this motorcycle.
"The Model 9 soon earned a reputation as a very fast and reliable sports tourer... engine layout was state of the art for 1924.

"The two overhead valves were operated by pushrods and rockers and inclined in a hemispherical cylinder head at a steep angle. Each valve had three external coil springs and the rockers were supplied with greasers and equipped with return springs.

"The cylinder head included dual exhaust ports and the lubrication was dry sump with a mechanical double gear pump. The conrod ran on roller bearings and the crank in three ball bearings and, unlike most British singles of the time, the primary drive chain was totally enclosed in an oil-bath, cast alloy case....

Streamlined housing filled with oil encloses chain drive.
The Sunbeam Little Oil Bath Chaincase.
"Sunbeam designed an entirely new frame for the Model 8 and 9, providing... a detachable, sloping top rail to facilitate access to the cylinder head."

The Marston-Sunbeam Club & Register notes that the 1924 Model 9 was called "the Parallel" because of this top frame tube and the one above the flat tank.

Photo illustration showing lower of two two rails removed.
Detachable frame rail is shown in 1924 article in The Motorcycle.
And here's something I should have noticed: "There was no kick start so being fairly adept at a running start was a necessity." A kick start was added for 1926 and the old-fashioned flat tank was replaced with a saddle tank for 1929.

Why had I never known more about The Sunbeam? An old story. Sunbeam fell into the hands of a conglomerate that sought to cut costs. Parts were outsourced, quality declined. The Great Depression forced prices down.

"The Model 9 cost 105 guineas in 1924 when it was released but, 12 years later, the list price was £66," Motorcycle Trader wrote.

Motorcycle on display in museum.
The Sunbeam Model 9 didn't pamper its owner. There was no kick start until 1926.
BSA acquired the Sunbeam name in 1943, moving production to Redditch. Motorcycle Trader again: "BSA Sunbeams bore no relation to the pre-war machines. The final Sunbeam motorcycle was built in 1956 but scooter production continued until 1964."

A sad history, perhaps, but one I was glad to learn.


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