Bultaco Builds a Trials Bike To Spread Trials Worldwide

Francisco Xavier  Bulto, from his beginnings in the motorcycle industry, was interested in building competition motorcycles.  He had co-founded Montesa and was their chief engine designer, but he left Montesa after a dispute with his partner, Pedro Permanyer, who wanted to withdraw from motorcycle racing.  Paco, as his friends called him, saw competition as a way of spreading his motorcycles' name, and of course, sales.   When he founded his own company in 1958, he immediately began building race bikes.  To his success, he employed well known British riders to compete on his road racers, thereby achieving vital recognition for Bultaco.  Next, he decided to build scrambles bikes, which led him to Don and Derek Rickman.  The Rickman brothers would not only bring Bultaco World Champion motocross success, but by providing Bultacos with a proven British chassis, they helped to vastly increase his market in the United Kingdom.  At that time, in the early sixties, trials was almost exclusively a British sport, and completely dominated by British built bikes.  However, there was a push to bring trials to the European continent, and interest in the sport was also taking place in the U.S.

    In 1960, when his company was only two years old, Senior Bulto introduced his first off-road trail bike, the Sherpa N. He would later have riders make whatever changes they deemed necessary to this bike to compete in trials, the Scottish Six Days and the ISDT.  With these modified Sherpa Ns his riders were able to bring home some second class awards, showing the bike had potential. 

    As an engineer, Paco was looking for "the" person who could take his product and modify it further to make it a winner.  In those days there was really only one person who stood out among all others, to do what he hoped for, and that person was Sammy Miller. 

    Though Sammy had been competing on an outdated Ariel 500cc single, he was virtually unbeatable in trials.  Much of the reason for this was Sammy's drive to constantly upgrade and modify his bike, making it lighter and better handling all the time.  Senior Bulto was keenly aware of Sammy's abilities; his engineering skills, as well as his riding ability, so he arranged for a secret meeting with Sammy Miller to see if he could be persuaded to help with the development of a Bultaco world class trials bike

    Bulto's timing was perfect, for Sammy's contract with Ariel was about to run out.  Ariel had recently been purchased by BSA, and he was not happy at BSA, nor even well know by management despite his numerous wins in all types of racing, but especially trials.

    It was during the ISDT in Germany in September of 1964 that this meeting with Sammy took place. At that time, Sammy had the opportunity to try one of the modified Sherpa Ns.  It's straight down forks, a Groble works style tank, short wheel base and lower center of gravity all appealed to Sammy's riding style.

     With his contract soon ending with Ariel, Sammy went to Barcelona, Spain, first without, and then with his Ariel Gov 132 and proceeded  to work on development of what we now know as the Bultaco Sherpa T Model 10.

    In just twelve days Sammy was able to modify a stock Sherpa N with a 196cc motor (the rarest production Bultaco at only 28 produced), and aboard it clean a section specially set up that he had been unable to clean with the Ariel.  The bike was then further modified by using Bultaco's newly developed 244cc engine.  Sammy selected the gearing for the four speed box, and had an extra flywheel added to the primary side of the motor.  This was the first Sherpa T.  As the prototype of the Model 10 production bike it utilized the Model 4 Sherpa N frame.  In November of 1964 Sammy Miller signed on with Bultaco and immediately started competing on his new Sherpa T, licence plate 669 NHO.  His last day of contract with Ariel was in November on the Saturday of the British Experts Trial.  This he won aboard the Ariel.  The next day he competed on the Sherpa T and won the King's Norton Club Trial in the Cotswolds.  However, world wide recognition of the Sherpa T would not come until May 8, 1965 when Sammy won his sixth Scottish Six Days Trial aboard 669 NHO.  This victory was taken for the first time by a two-stroke motorcycle, and a non-British bike since the race's beginning in 1902.  The Sherpa T was now on its way to being the most famous of all trials bikes.  A revolution had begun that was to bring Sammy Miller 58 victories in 80 events the first two years riding the Model 10, and more than 1000 first place trophies over his career.  With the Bultaco Sherpa T leading the way, trials would soon spread by leaps and bounds throughout the world.

Published sources of information:

Spanish Trials Bikes    By Don Morley  1988   Publisher: Osprey Publising Limited

Historia De La Sherpa T    By Albert Boet  2001  Publisher: Francois Stauffacher

Sammy Miller on Trials    By Sammy Miller  1969  Publisher:  Parkhurst Publishing Company

I would like to give special thanks to Cody Tellis of Bultaco West. His beautiful restorations of Model 10 Sherpa Ts and his knowledge of these bikes was inspiring and led to the publishing of this article.

I would also like to thank Allen Gracey for the photos of his 1967 Model 10 which he has recently done an excellent job restoring.

Bultaco Sherpa T Model 10 Photos 

Above are the American and English Versions of the Sherpa T Model 10.  Click the thumbnails to see a full sized photo.

Above are photos of MAVT member Allen Gracey's later Model 10 (1967).  This is the final form of the Model 10

Above is a photo of the three styles or forms of the Bultaco Model 10:  English, Works "Grenoble", And American.

The tanks are mostly what differentiated the three styles of Model 10.  On the left, the American tank was also used by British and European riders later on.  The "Flat Bottom" tank was stronger and held more fuel (2 gallons as opposed to 1.5 in the English "Round" tank).  The rarest tank, and one used early on, exclusively by Sammy Miller and perhaps by one or more of Bulto's nephews, was the works "Grenoble" tank, named for the Trial in Grenoble, France where it was first used.  It provided it's rider with a tighter turning radius with the front "indentations".

Last, but certainly not least is a close up of the Model 10 Motor with it's radial head and IRZ carburettor.  With it's extra flywheel on the primary side, it delivered smooth power with good torque at low rpms.   This photo also shows the skid pan used on the later models, and the very slippery solid mounted foot pegs.  In later models these were changed to folding pegs.  Sammy Miller had much to do with the developement of the early Sherpa Ts as he constantly made upgrades on his own machines, later adopted by Bultaco.

Sammy Miller in 1964 posing with his prototype Sherpa T

Additional Photos Below