The Promised Land – Part 5

At a certain point, visiting the Barber Motorsport Museum becomes an embarrassment of riches.

The human/biker brain can only absorb so much before it simply begins to overheat.

So, understanding that this brain may need to stop from time to time … like a truck climbing the Hakone Pass … to get the cerebral needle out of the red overheat zone, let me continue walking the floors of the museum and sharing some of the things that caught and held my eyes.

I’ll also apologise in advance for my obsession with anything with a boxer engine. When you’ve had at least one motorcycle with a boxer available to ride in one’s garage since 1983, it tends to color one’s perceptions of all things motorcyclic.

I’ll also cop to being a big fan of Edgar Allan Poe. Poe’s story, The Imp of the Perverse, describes perfectly that impulse within the human being of being unable to resist being drawn to anything somehow quirky, weird, nonstandard or self-destructive. Given a choice between anything good and anything somehow not good, Poe’s protagonist chooses perversely every single time, even despite knowing better.

If you’ve been reading Rolling Physics Problem regularly, you now fall into the category of a horse that does not need to be shown to this particular water.

The perverse, then, is the perfectly natural segue to the subject of one Alfred Angas Scott, and his motorcycle, the Scott Squirrel.

As an engineer brought up on steam power, Scott had no problem ‘seeing’ 2-stroke internal combustion power.

And designers and engineers that are unfettered — that are thinking out of the box, because no ever told them about the box in the first place — make the things that they, in the minds eye, can see.

So while some guys in Milwaukee were making stone-ax simple 4 stroke air cooled engines – driving things via variable tensioning of leather drive belts and wondering if a cam-driven intake valve might be a good idea, Alfred was some other where entirely.

Aflfred was thinking about big – by the standards of the day – 2 stroke power, water cooled, no less. Instead of dropping that engine into a bicycle – which was more or less what everybody else was doing – Al designed a chassis that optimized the location and roll moment of that engine, placing it as low and forward as could be managed. Drive was via a clutched, two speed transmission and chain. In keeping with studiously avoiding what everybody else was doing, Scott located his fuel tank underneath the rider instead of ahead of him. That location, again one that would provide mass centralization, is one that one still see used on modern street and race motorcycles.

If you squint real hard, and are willing to overlook details like the difference between rotary and reed valve intakes, you can almost merge the thing with the last production Yamaha 2 stroke streetbike the RZ350, as well as all of the 2 stroke twin racebikes that preceeded it.

Except that those motorcycles were built in 1985, and Scott was working in 1905.

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Did the Scott work as a sports motorcycle?

Did the RZ?

Scott Motorcycles set lap records on the Isle of Man in 1911, 1912, 1913 and 1914, and won the TT in 1912 and 1913.

So yeah. It worked.

I talk a lot about the shared basic vocabulary of motorcycle design — two wheels and tank and a motor — think international symbol sign for motorcycle or Norton Manx.

Alfred Angas Scott managed to build motorcycles that went like stink without making use of any of that standard vocabulary.

***

I stop to look at this 1926 ABC, because, well, its a boxer.

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Upon reflection, its more than that, though.

The Sopwith All Brittish Engine company worked through the details of this familiar looking motorcycle in the early 19-teens, and was selling the bike in volume as soon as the First World War ended.

And in 1926, when they had seen more than a few R32s, they took BMW to court to enforce ABC’s Patent for this engine design. And lost.

What if?

***

Have you noticed its always about doing better?

A young Englishman named George Brough — the son of a motorcycle maker and a racer of more than a little skill — came by a little money when he came of age. George decided that if he was going to have a bike that was as good as bike as he was a rider he’d just have to make it himself.

Like every ripping good British bike story — and more than a few American ones too — the meat of the action moved to a few pints at the pub.

George and his dad Bill, along with the George’s mates, were raising the wrist in an attempt to conjure some inspiration. After enough rounds of inspiration had been consumed, and more than a few suggestions had been ridiculed and discarded, one of George’s mates had an idea.

“Hows ’bout we call it the ‘Brough Superior’?”

Bill Brough was heard to snort.

“I supposed that would make my bikes the ‘Brough Inferior’.”

Laughter ensued, but George was not deterred. The name stuck.

***

George’s bikes were handbuilts — stong stable frames and stronger engines. The entire bikes were assembled twice — once for fit and tune and then a second time after being disassembled for paint and plating. The bikes were guaranteed from the factory to achieve what were extremely elevated speeds for the 1920s — 80 mph for the SS 80 and 100 mph for the SS 100. Bikes that could not achieve those speeds on the road could be returned to the factory to be tuned by George and his mates until it could.

Broughs set several world speed records and became the single prized material posessions of TE Laurence, whose first Brough was named Boanerges — which means Sons of Thunder in ancient Arameic — and then six more until the SS100 that he died riding. At the time of his death, Laurence had an eigth Brough on order and being built for him.

Brough Superiors were built in tiny numbers — 3000 bikes over 22 years — by hand by skilled craftsmen. Looking at them is looking at an artwork — all chrome and brass plating, insanely deep black laquer — and a harmony of design that is unique.

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The Brough is the picture of ease and strength. From the saddle, in top gear they felt they could run up top until one ran out of petrol or ran out of road.

***

Mr Edward Turner’s Trumph Speed Twin motorcycle, first sold in 1937, became one of the most iconic motorcycle designs of all time, and formed the core of Triumph’s products until the end of the original triumph Engineering Company in 1980, and still has echos in the modern Heritage Twins sold by the sucessor Triumph Motorcycle Company.

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For a period before the introduction of the Honda CB 750, the Bonnevilles were the sales and racetrack leaders in the USA.

This Motorcycle is not a Triumph, though. Or a BSA, whose twin it more closely resembled.

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And you’d need to read the Tank badge to actually be able to tell.

Signs like the Kawasaki W1 and W2 motorcycles were the writing on the wall for the British Motorcycle Industry, and that writing was writ large. Companies like Kawasaki were completely capable of manufacturing products that literally beat the British at their own game. The W motorcycles were more precisely manufactured, had better tolerances and machining — companies like Kawasaki were able to identify design defects and promptly remedy them where their British counterparts seemed incapable. The resulting products were oil tight, and mechanically and electrically reliable in every way.

Put the British and Japanese motorcycles to functional comparison, and the Japanese bikes won, rolling away.

There would eventually be a rematch, but the original knockout kept the British motorcycle industry down for for decades.

***

I love motorcycles.

I also love electric guitars.

It is very rare that these enthusiasms combine, in my experience, except maybe in the stories of Peter Egan.

In real life, though, its exceedingly rare.

Hell, the case of designer and engineer Paul Bigsby might be unique.

I know Bigsby’s work from perhaps his most famous creation, the Bigsby Vibrato tailpiece.

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Bigsby is actually once of the three or four most significant engineers in the history of the electric guitar, truly able to stand toe to toe with Les Paul and Leo Fender. In addition to the famous ur-whammy bar, Bisgby is also credited with designing the original pedal steel guitar, the first double neck electric, the first through-stringed electrics, and the shape of the headstock eventually used by Leo Fender on his Stratocaster guitars.

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Bigsby was a metalcraftsman, and his products made frequent use of stout chromed steel and aluminum castings, usually with his name cast in using elegant script.

Once when I was attending a motorcycle show, I was presented with an American motorcycle that I hadn’t seen before. What struck me about it were some of the castings and cases, which made use of that same familiar Bigsby script.

“What are the chances?” I thought.

One hundred percent, apparently.

That motorcycle was a Crocker, and Paul Bigsby was their designer and engineer.

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The Crocker was guaranteed by its manufacturer to be able to beat any Harley or Indian in any contest of speed. It was a guarantee that Crocker never had to pay out on.

Crockers were only built in minscule numbers from 1936 to 1942, and are now some of the most valuable and rare American motorcycles ever built.

Just goes to show that if you were an engineer living in California in the late 1930s, and knew how to design things made out of metal, go fast and guitars were likly both living in your neighborhood.

***

And now, a boxer weirdess interlude.

When you’ve laid wrenches on and been underneath more BMW boxers than Doan’s has little back pills, you tend to look at details. So here are some pretty weird and wonderful things that caught my eye.

This is a BMW R12 — a flathead boxer sold between 1935 and 1942.

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I freely admit that my direct BMW experience does not cover bikes built before 1970, so I’m out of my depth with bikes this old. What caught my eye on this single carb model was the chromed steel tube leading from the exhaust pipe nut back to the alloy exhaust manifold.

I’ve seen some modern vehicles that inhect small amounts of combustible mixture on the far side of the exhaust valve to promote ‘afterburn’…not for power but for cleaner exhaust emissions. This likely wasn’t one of those, but its purpose had me stumped and flailing back to the Googling thing.

The answer was a a bit of a surprise. The R12’s Flathead Setup was prequently used for a sidecar tug, and frequently in cold, crappy conditions, ’cause, well, its a sidecar. And in said cold, crappy conditions, the warm up behavior of the R12’s single carb setup, with its lengthly alloy intake plumbing was somewhat less than soul stirring. In short, the bike wouldn’t atomize fuel or keep it atomized worth a polished turd until some heat made its way back there, which, if conditions were cold enough or crappy enough, would happen right about well, never.

The solution was this little chrome pipe, which carried enough heat from the exhaust port/exhaust pipe junction back into the manifold to allow fuel to atomize and stay that way.

Problem solved.

***

With one problem solved. let’s talk about another boxer problem.

One might wonder why we love boxers so much if there are so many problems.

Stop wondering that.

These are not the droids you are looking for.

Anyway, classic BMW boxers have pushrods. Pushrods which ride in tubes. Pushrods that ride in tubes which, if you keep them long enough, are sure to leak.

Just the thought of leaking pushrod tubes has my mind’s eye supplying an image of buddy Paul Mihalka. Paul was working his desk at the BMW dealer one day, when I had made a stop at the parts department for two sets of pushrods seals.

“What have you got?”, asked Paul.

“Some pushrod seals.”

The rest of Paul’s presentation was in pantomime, but its meaning was crystal clear.

With one hand, Paul held the invisible screwdriver — with the other, the invisible hammer. The invisible hammer smacked the invisible screwdriver, driving in, without a doubt, the invisible retainer with its leaking invisible pushrod seal.

“Tink Tink Tink.”

Paul had a huge smile on his face. He knew that any BMW rider older than 5 seconds old knew exactly what those motions meant, having done it more times than anyone could remember — think of it as a boxer lover’s secret handshake.

So that is why this motorcycle, built by Reg Pridmore Motors of Ventura California as a Daytona Racebike, is so interesting.

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Reg, who, it can be assumed, knows a little about boxers, was fairly confident that the top ends of this race motor would need to be removed and replaced fairly often, and would be operated under thermal and mechanically stressful conditions that would routinely cause pushrod sealing to fail.

So, rather than re-comitting to a life filled with hammers, screwdrivers, punches and “Tink Tink Tinks”, Reg or one of Reg’s men resolved that he could do better.

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It took all of the aforementioned 5 seconds of me looking at the motor of the RPM Racebike for a Giant Looney Toon Lightbulb to come on over my head with a giant high amperage relay closing sound — “ZZZZntThunk!”. The RPM Guys had threaded the pushrod tubes and done some fancy close order welding to join a flanged retainer to a threaded collar. The only thing between what they’d done and perfection would have been to add a set of flats for a wrench.

To pull the top end, one only needed to spin the retainers up the tube. Upon reassembly, spin back down. Develop a leak? Take a 1/4 turn on the retainer to place a bit more pressure on the seal.

Brilliant.

Now if you will excuse me, my Slash 5’s pushrods are leaking, and I feel a good “Tink Tink Tink” coming on.

***

This next item is only marginally boxer related, but bears a short mention anyway.

All of my boxers – being aged – have made use of tubed tires. The Metzler natural rubber tubes that I prefer always come with a vavle stem cap that includes a little stem service wrench, which allows one to make sure the valve cores are seated properly to avoid leaks, and to remove the stems when tires are being mounted.

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I had assumed that said freebie, which I always ensure to have on my bikes, was some sort of tire manufacturer good idea.

Looking closely at an R32, I saw this.

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Clearly original, clearly cast bronze, and clearly over a half pound of metal.

Two conclusions. One – Boxer guys like valve stem tools. Two – tire balance is a modern concept.

 

 

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2 thoughts on “The Promised Land – Part 5

  1. Greg, great article as always.

    The racebike pushrod tubes are fascinating.. it does appear they’re threaded, but at first glance it almost looked like metal accordion type piping, quite commonly used in the high-vacuum world. Used correctly they could be designed to exert a constant pressure against the seals, even at varying lengths.

    I’m also puzzled by the rather obviously loose bolt in the same photo – it should be tightened since it has a lockwasher on it. I wonder if this bike has gotten the full Barber museum restoration, or simply a cosmetic one..

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