We use cookies for analytics, advertising and to improve our site. To find out more see our privacy policy.
Removing the Corbin Speedo

Removing the Corbin Speedo

Starting the way to Cannonball 2025:

„A good speedometer is not merely an accessory, it is a positive necessity for every motor vehicle"

We’d definitely confirm this from today's perspective - in 1925 this sentence was apparently a newsworthy insight. And it is no coincidence that the quote comes from a technical manual published by the Corbin Screws Inc, New Britain, Connecticut, USA.

The Corbin company emerged from the American Hardware Corporation, founded in 1878, and manufactured not only screws and bolts of all kinds and for all purposes - from ovens to dog leashes - but also vehicle accessories. In addition to complete brake systems, from around 1910 these were primarily speedometers for cars, trucks and motorcycles, at times also under the brand name Corbin-Brown.

In 1928, the year our J model was built, Harley-Davidson

motorcycles rolled off the factory line without speedometers. If you wanted to know how fast you were barreling down the roads on your murdersickle, you had to dig deep into your pockets: in 1918, a speedometer without drive cost 12 dollars, with angle drive cable, road gear sprocket, brackets and all the trimmings it quickly came to 25 dollars - that would be around 500 of today’s dollars. Back then this was quite steep - today a Corbin speedometer is a "hard to find" object, a better word for very expensive: if it's a working Corbin speedometer you want, you can expect to pay well into four figures. If you can find someone to sell it, that is.

Technically speaking, the Corbin speedometer is a

"governor type speedometer" that works on the principle of centrifugal force: a flexible cable transmits the speed via a pinion on the rear wheel into the speedometer, where it moves the pointer against the resistance of a spring. Or in the words of Corbin sales literature:"The Corbin-Brown Speedometer is built on the centrifugal principle of physics. Its centrifugal governor has four balance weights so sensitive that they respond to the slightest variation in speed. This centrifugal principle of the Corbin-Brown Speedometer is the same as that applied to the regulation of engines. It insures absolute regularity of revolution."

In a 1918 catalog, Corbin praised his own speedometers

as particularly reliable and insensitive to temperature changes, electrical fields or shocks caused by uneven roads or railroad sleepers - not least because they consisted of "few, large and strong parts". The speedometers were offered in different versions: with a maximum indicator to document the maximum speed reached; with an odometer that went up to 100,000 miles and with all accessories to connect the speedometers to the rear or front wheel. They were also available with mph and km/h dials - the latter is the case with our Model J. It is therefore conceivable that it was intended for export to Europe.

As already mentioned, Corbin speedometers

are extremely sought-after items today. For owners of historic Harleys such as our Model J, however, it is usually also important that these measuring instruments work reliably. We’re happy to say that we have put together a selection of spare parts that are essential for the operation of a Corbin speedometer and which we are presenting here.

We can’t rule out that we will have to use some or all of these parts on the way to rebuild our Flying Turtle. But that's still a little way off.

Click here for our YouTube channel (don’t forget to subscribe to get a notification when a new video is up.)

The road to Cannonball 2025
With the start of the new year the Wrecking Crew is embarking on a new project: The Cannonball 2025. A motorcycle endurance race across the continental USA, coast to coast, 3.500 miles in length. On vintage motorcycles, some of them up to a hundred years old.
Our Harley-Davidson J model, named "The Flying Turtle", which we will be racing in 2025 hasn’t cracked the 100 years yet, but it isn’t far off either with its 1928 vintage.
The history of this particular J model is hidden in the murky depths of the last century, but we know that it entered the W&W fleet of V-twins by way of a couple of trade ins from Switzerland. It has been in use on and off ever since, and without giving any trouble. Which is all the more surprising ’cos none of us ever bothered to have a look see inside her innards.
But, with the extreme long distance on the horizon, comprising mountain ranges, desert roads and miles of solitude that will have to be conquered in the three weeks and 3.500 miles to come we decided to tear down "The Flying Turtle" down to her last period correct washer, inspect everything and rebuild her just like Milwaukee intended her to be.
An epic quest, you could say, but our Wrecking Crew team are just the guys to handle it:
Paul "The Cyclery" Jung has done it before, riding the "Cannonball of the Century" in 2016. He’ll be chief mechanic this time, in the headquarters' workshop during the 2024 run up and on the track in 2025, driving the support truck (help is only legal before the start and after the finish line of each stage). His experience as a senior AMCA judge might come in handy here.
Chris Sapper will be riding "The Flying Turtle". He has plenty of Harley miles under his belt, and loads of wrenching know how in his muscle memory. So that he has the complete picture of what is going on inside his ride, and to know what to do if anything goes awry, he will be wrenching on the restoration project under Paul’s supervision from day one.
It’s still a few days until the starter’s flag drops. We’re now busy dismantling, evaluating and measuring all the parts – and we’re filming whenever the Wrecking Crew is working on "The Flying Turtle". Every Wednesday there’ll be a short video update under the motto ’Wednesday is Wrenching Day’!

more …