BIKES YOU’VE NEVER SEEN BEFORE: THE IRISH-BUILT URM 500

On Jul 10, 2023 Last updated Jul 10, 2023

Dr. Gordon Blair standing behind the prototype URM 500. The engine was the good doctor’s baby, while the frame was the handiwork of Colin Seeley.

Dr. Gordon Blair was a Professor of Mechanical Engineering, Dean of Engineering, and Pro-Vice-Chancellor of the Queens University Belfast (QUB). He wrote over 100 technical papers, three text books and had nine patents granted. Most of all Gordon Blair loved motorcycles and, in 1965, embarked on a journey that would would make him the most famous two-stroke engine designer in the world and take the Queen’s University Belfast with him. No, it wasn’t a scientific tome based on engineering research, it was something more practical—a racing motorcycle with an engine of his own design. Blair’s research work on engines had enable him to design the most powerful two-stroke engines on the track and gave him the bravado to prove that against the the biggest factory motorcycle teams. In 1969 these research and design efforts began bearing fruit when QUB’s rider Brian Steenson finished second to the great Giacamo Agostini in the 1969 Ulster GP at Dunrod on a QUB race bike.

With only two bikes ever completed and only raced in Ireland, photos of the URM 500 are very rare, but not as rare as actual URMs.

Gordon Blair felt that the future of racing lay with two-stroke engines and when the 500cc two-stroke engine design was put in the hands of Irish road racing star Ray McCullough it was magic. McCullough gave Blair seven Ulster Grand Prix victories against greats such as Giacamo Agostini, Mike Hailwood and Stanley Woods. Blair’s road racing endeavors aside, he wanted to build a motocross bike to test out his theories in the dirt. The master plan was to take the 500cc, single-cylinder, two-stroke, QUB 500 road race engine and put it in a motocross frame. The goal was to build the first competitive 500cc class motocross bike to ever come out of Northern Ireland.

Colin Seeley holds the QUB 500cc road race engine. when Dr. Blair went road racing, he relied on Seeley frames.

There were three motives driving Gordon Blair’s motocross dream. First, 500cc two-stroke singles, once a powerful force in European road racing, were being forced out by the increasing complexity and performances of Japanese twins. Second, it was possible to make more money selling 500cc two-stroke motocross bikes than road race bikes (in Seeley frames). Third, Blair already had the motocross engine in his hands. He planned to take the QUB 500 road race engine and tame its peaky high rpm powerband by changing the port layout and redesigning the exhaust to improve low-end torque.

Ray McCullough raced the QUB 500 to road race glory—an Irishman on an Irish bike. When he was forced to switch to Yamaha twins, he had Gordon Blair work on the those engines.

The motocross engine got financial support from the Irish government because of its potential to bring motorcycle manufacturing to Northern Ireland. The QUB engine produced 65 horsepower (at 7600 rpm) and was detuned to produce 40 horses at 6000 rpm for the motocross version. It had a 91mm x 76mm bore and stroke, 494cc displacement, 38mm Amal Concentric carb, 7.5:1 compression ratio and a four-speed transmission. The engine weighed 75 pounds with the ignition, carb, shift lever and kickstarter.

Gordon Blair couldn’t fix the Greeve’s quirky design, which was totally British, but he could add 11 extra Irish horsepower.

The motocross bike was called the URM 500. URM stood for Ulster Racing Motorcycles. It was completely designed by Blair and his engineering students at Queens University Belfast (QUB). Sadly, only two URM500s were ever built. The original MK1 used a QUB-designed frame (built by Colin Seeley) and was raced by Robert Wilkinson, while the MK2 version used a Maico frame and was raced by Irish racer Winston Norwood. The MK2 remains on display to this day at Queens University Belfast.

The 1973 Greeves Griffon 380 QUB.

Gordon Blair would go on to greater things outside of Ireland. The famous Greeves brand was suffering under the onslaught of Japanese motocross bikes that were faster, newer and lighter than the European brands, but Greeves was still a force in the Open class. Bert Greeves ask Dr. Gordon Blair to reworked the Greeves 380 engine. Blair upped the horsepower by 11 horses and, in 1973, Greeves introduced the Greeves Griffon 380 Q.U.B. (a nod of thanks to Queens University Belfast). Unfortunately, the QUB would be the last significant Greeves, as the company fell on hard times in 1975. Professor Gordon Blair died in October of 2010 at 73 years old.