ROBERT S FAMILY WORLD CHAMPIONSHIP BIKES
R I D E R E V I E W
P64
Vital Ingredient
The chance to test the actual reverse-
cylinder OW48R Yamaha which Roberts
Sr. rode to win the last of his trifecta
of 500cc world titles came at Assen,
the circuit at which this piece of lateral
thinking hardware made its debut back
in June 1980. Thanks to the enthusiasm
and commitment of British collector Chris
Wilson, and the inspired restoration skills
of former factory race mechanic Nigel
Everett, the yellow and black Roberts
Yamaha represents yet another vital ingre-
dient of the early days of 500 GP two-
stroke history saved from the scrapheap
and returned to the racetrack as part of
the Wilson collection.
40 Years On
"The OW48R is basically a set of TZ500
cassette-gearbox crankcases with a
special factory top-end on them, with
guillotine power-valves, a quite different
stud pattern for the separate cylinders,
and special porting," says Nigel Everett
of the OW48R motor, whose only weak
point seems to have been the extract-
able gearbox—a fact confirmed by former
works Yamaha TT-winner Charlie Williams,
who also rode the Roberts bike at Assen
KENNY ROBERTS
1980 YAMAHA YZR500 OW48R
Is there a Yamaha more
legendary than that of King
Kenny? This is the steed
from his final championship
year of 1980.
