This is a
short blog on an innovative and influential motorcycle race frame.
Eric
Shepherd was a motor mechanic by trade and had a garage in Perth. He was also a
keen motorcycle road-race competitor, who raced at both the Scottish mainland
circuits and IOM TT. In the early 1960’s Eric
built a couple of highly unusual frames for the period, in which were fitted
Triumph twin engines. The senior class bike used a 500cc unit construction engine
and the junior class a 350cc unit T21. This pair of bikes was raced by Eric
throughout the 60’s and into the early 1970’s and every year he was to be found
at the Beveridge Park race meeting in the summer. He also raced both machines
at Gask and Crimmond in 1967.
Shepherd 350cc Special - Crimmond 1967 |
Eric also
raced in both the Senior and Junior TT races for the first time that year and his frame caused
considerable interest in the paddock. Unfortunately he finished in neither
event, but his radical frame design had not gone un-noticed and would be seen
again.
In 1980 the complete rolling chassis from the 500cc bike was purchased minus the Triumph engine. Hugh Ward fitted a 350cc BSA Goldstar engine, canting the tall engine forward in order that it would fit below the main frame tubes. He also used the BSA gearbox and clutch. This bike was subsequently raced by Dick Irwin from Haddington in the Manx Classic Grand Prix.
In 1980 the complete rolling chassis from the 500cc bike was purchased minus the Triumph engine. Hugh Ward fitted a 350cc BSA Goldstar engine, canting the tall engine forward in order that it would fit below the main frame tubes. He also used the BSA gearbox and clutch. This bike was subsequently raced by Dick Irwin from Haddington in the Manx Classic Grand Prix.
Shepherd 500cc Special with Goldstar engine fitted |
So, what was
innovative and influential about Eric Shepherd’s frames?
Well firstly
they were very low and sleek and had a continuous tube running from the bottom
of the steering head to the swinging-arm pivot on both sides of the frame.
There were also no front down-tubes to the frame, the engine and gearbox being
suspended in their engine plates from a cross-member between the main frame
tubes. A steady tied the cylinder head to a second cross-member between the
main tubes, which was positioned just back from the steering head and provided
additional support to the engine unit.
You have to
remember this was 1964 and nothing like this had been seen before. If you
accept that the most radical improvement in frame design since the 1950’s came
in the form of the McIntyre Matchless, which had been fabricated at Bellshill
by Bob & Alex Crummie in 1962, then one has to acknowledge that the
Shepherd Special was also very innovative.
To confirm
this point, let us look at the then current ‘state of the art’ racing frame
produced by a well-respected and most able fame manufacturer.
Seeley Catalogue 1968 |
Undoubtedly
a light and good handling machine, when judged against the hot-bed of ideas
that are found in a racing paddock, it is fair to say the basic frame concept
was somewhat conservative in approach. To put it in perspective, the above was
the design offered in the 1968 edition of the company catalogue, a full 4 years
after Eric had produced his pair of radical machines.
So was the
Shepherd frame influential?
You will
have to be the judge of that, but let us look at the MK4 Seeley frame. As in
the Shepherd frame, the main tubes run continuously from the bottom of the
steering head to the swinging-arm pivots on both sides of the frame. The cross
and additional frame-bracing tubes are very similar in disposition and the
overall concept remarkably akin.
Seeley Mk4 Commando |
Shepherd Special |
Casting our
minds back, let us remember that the MK2 frame that followed on from the one
shown in the 1968 catalogue was also a full duplex affair. In the MK3 frame the
main frame tubes ran from the swinging-arm pivot to the top of the steering head,
crossing inside the seat-rail tubes below the petrol tank. This was also the
first Seeley frame that dispensed with the front down-tubes, but suffered from
premature failure due to a lack of section at the point where the tubes
crossed.
So it was
not until the 1970’s that a very similar frame to the Shepherd Special was
produced in any numbers by a major specialist frame manufacturer. Judged on
that fact alone, Eric Shepherd’s frame was indeed influential.
Eric was my friend at secondary school and throughout our teens working on bikes at the lockup in Letham..I helped at the racing too..I rode the unique framed 21 handling was amazing. His TT bike was a featherbed frame bought from me and he used a dominator engine. I was best man at his wedding..I moved north in 1971and was away for 43 years.now in Perth..Sadly Eric passed a few years ago
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