Clement Salvadori tells us about the beginnings of motorcycle trials and one of the best trials bikes ever built, the 500T.


by Clement Salvadori

Owner Steve Eorio of Paso Robles, California, and his 1951 Norton 500T.

Motorcycle trials is a peculiar sport, having nothing to do with power and speed, just the dexterity of the person at the handlebars and the quality of the machine being ridden.

It was popular in Great Britain over a 100 years ago, when people set up courses over terrain that motorcycles were not built to go over, like a field of broken rocks or a steep muddy incline. Requirements for success were an excellent sense of balance, and a rapport between man and machine — apologies for the sexist approach, but it is pleasantly alliterative, and I doubt that any woman signed up for the 1909 Scottish Six-Days Trials. Many women are competing in this sport today.

Move forward 40 years, and in the aftermath of World War II Norton came up with one of the best rigid-framed trials bikes ever built, not to mince words. But it took a while to get there. Back in 1902 James Lansdowne Norton produced and sold his first motorcycle, using a bought-in V-twin engine. A few years later he developed his own sidevalve 490cc single-cylinder engine, with a bore and stroke of 79mm x 100mm, calling that the Model 16. In 1922 he built a companion machine, keeping the cylinder while placing the valves on top. That version was called the Model 18, with a slightly sportier ES2 (Extra cost, Sporty, 2nd version of OHV engine — aka Easy 2) introduced in 1932, and the engine in that model being the predecessor to the engine in the 500T — considerably improved, of course, but entirely reliable.


And what about the chassis? The ES2 had a cradle frame early on, while in the 1930s the company’s lowest-price 500, the Model 16, used an open frame, meaning the engine was bolted in between the front down-tube and rear seat tube. This came in two versions, the 16H for Home service, and the 17C for sale in the Colonies, which generally gave it a few changes to cope with the bad roads out there in Africa and Asia. Norton had a good reputation in the motorcycling world, but wasn’t very clever about coming up with catchy names.

Moving on

A little bit more history is required. In the 1930s the Great Depression was doing great harm to the world, but Brits were determined to entertain themselves with trials competitions, as well as having a beer at the local pub, as in public house. Norton had a dozen bikes in the 1935 catalog, and for an extra five pounds the buyer could get the trials kit installed on several of these, which included extra ground clearance, trials ratios in the transmission, and knobby tires. The British government had also put out a bid for a suitable motorcycle for the military, reliability being the major concern, and the Model 16, with the side-valve 500 single, got high points. Almost 100,000 WD16H models were built through the World War II years, and many survived, most to be sold off to civilians.

motorcycle wheels

Image by Clement Salvadori

The 500T has 7-inch drum brakes, both at the rear (left) and at the front (right).

The war ends, Norton wants to get back to civilian business, and in 1946 the company came out with the ES2, which had a plunger frame. The trials version was hooked to a sidecar (yes, trials had a sidecar class) and it worked well, but it was not a good solo ride. Light weight and agility are the keys to a successful trials bike, so the trials department decided to try using the open-frame 16H chassis, with a serious crankcase shield to protect the engine. Critical modifications were made in order to shorten the wheelbase from 56 to 53 inches, this being done by making new rear frame stays and modifying the yoke for the Roadholder forks. This made it a tight fit for the 500cc OHV engine, but it did go in, bringing the weight of the 500T down to a couple of pounds under 300 — as long as the heavy rear-axle stand and toolbox were removed. A side-stand was stock.


Image by Clement Salvadori

The 500T uses a 500cc OHV engine (left) and wears Roadholder front forks.

A chain-driven BTH magneto supplied the spark, and an Amal “Standard” 276 carb, with a 1-1/16-inch internal bore, fed the fuel from the 2.5 gallon tank to the alloy cylinder head, where the compression ratio had been reduced a bit, from 6.6:1 to 6.1:1. The barrel was also alloy, with a steel liner. Some 26 horsepower were put out at the crankshaft, passed on to a 20-tooth left-side primary drive, with an oil-cooled chain running down to a 16-tooth transmission sprocket, and a 4-spring multi-plate clutch leading to a wide-ratio 4-speed gearbox, 5.5, 8.1, 13.15, and 18.1, giving it lots of low-speed grunt and a top end a shade over 70mph.


A Lucas lighting system was an option for those who wanted to ride to the races. A well-sprung solo saddle kept the rider comfortable on the road, though he would mostly be standing on the pegs during a competition. The oil tank seen under the saddle of the photo bike was chrome-plated by some previous owner, and a very visible change from original is the American SuperTrapp exhaust, with an adjustable turn-out end cap.

The front wheel had a quarter-circle aluminum fender, the rear a half. The front wheel carried a 2.75 x 21-inch tire, the rear, 4.0 x 19-inch, with 7-inch drum brakes on both. Steering lock with the Roadholder front forks was a full 100 degrees. Some of the factory riders were bringing home blue ribbons before any official announcement of the existence of the 500T, with the bike being first shown to the public at the 1948 November show at London’s Earls Court … along with the new 500cc twin, the Model 7 Dominator. The 500T soon found a market among the trialsters, and won the 1950 ISDT.


Change was coming, but not for the rigid-frame 500T. In 1952 Norton was bought by AMC (Associated Motor Cycles) which also made the AJS and Matchless machines, including trials models. AMC was not inclined to spend the money to build a good rear suspension for the 500T, and about the only change made was a larger front brake for the 1954 model. Very few were made that year as the trials world was changing drastically. Lightweight little 2-strokes with full suspension like Greeves and Bultaco were winning!

But the 500T left behind great memories. “The finest rigid trials bike to be produced by any factory,” wrote Don Morley, famed trials rider and writer. Not bad praise.

The 500T in the photos is a 1951 model, owned by Steve Eorio of Paso Robles, California. MC

Updated on Feb 13, 2022  |  Originally Published on Feb 4, 2022

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