CN
III ARCHIVES
BY LARRY LAWRENCE
P110
The First One Brand National
H-D Racing Manager
Dick O'Brien (left of
Kidd) enjoyed the
all-Harley main at the
Terre Haute Half-Mile.
A
ugust 17, 1975 marked
a milestone AMA Grand
National race. That day on the
Action Track Half-Mile in Terre
Haute, Indiana, for the first time
in history, every motorcycle that
ran in the national was a single
brand. That brand? Harley-
Davidson.
It's amazing to think it took 21
years for the series to have its
first single-brand national.
There was a perfect storm
that day in Indiana, to set up an
all-Harley day at the national.
By 1975 the powerful British
brands of Triumph, Norton and
BSA were basically closing
down and very little support was
given to the AMA Grand National
Championship in '75 with Mark
Williams getting limited back-
ing from Norton. So with the
British bikes pretty much out of
the way, the only serious chal-
lenge to Harley on the flat tracks
was defending national champ
Kenny Roberts on the full factory
Yamaha. Yamaha also supported
Gene Romero to a lesser extent.
Also, that year there were
updates to the Harley-Davidson
XR750, which gave the bike both
more usable power and reliability.
The aluminum XR was in its fourth
season and the Milwaukee-based
brand was benefiting from tons of
development in those years from
numerous factory and factory-
backed riders.
Yamaha was pushing the
XS650-based (750cc) to its ab-
solute limits. Tremendous head
work on the Yamaha had closed
the gap on the Harley, but
Roberts was still getting smoked
coming off the corners by the
grunt of the V-Twins. And with
the Yamaha on a knife's edge of
tuning, it was becoming unreli-
able and Roberts found himself
sidelined numerous times during
the '75 season. It got so frustrat-
ing for Roberts and Yamaha, in
desperation they turned to the
Yamaha road race engine, the
two-stroke TZ750 and Roberts
