Originally,
all Borrani wire wheels, no matter the size of the hub,
used two-eared knock-offs. Curiously, despite the name
change in the late 1930's, the earliest Ferraris came
with knock-ofs that bore the famous Borrani “hand”
logo surrounded by the words “Rudge-Whitworth Milano.”
Later this was changed to "Carlo Borrani Milano”
and about 1961 to "Route Borrani Milano.” Still
later the knockoffs supplied for the Borranis going onto
Ferraris had the prancing horse emblem.
The three-eared knock-off was actually an
American innovation. When Ferrari came to Indianapolis
in 1952 the Ferrari mechanics and specifically engineer
Aurelio Lampredi were impressed with the three-eared knockoffs
being used on the American Indianapolis race cars. Unlike
with a two-eared knockoff, when a car with a three-eared
knockoff came to a halt during a pit stop one of the ears
would be well positioned to receive a blow from a hammer.
Unfortunately, the safety czars in Washington,
D.C., decided that eared knockoffs were probably a danger
and so on USA-specification cars they were replaced by
octagonal nuts, requiring a special wrench in the took
kit to provide the means of loosening or tightening. Again
a point to keep in mind if you want to be a stickler of
originality.
There there is the question of straight versus
bent ears on the three-eared knockoffs There is considerable
evidence, including some of the Ferrari spare parts catalog
and the testimony of Silvano Borsari, who heads up the
Borrani department at Costruzioni Meccaniche Rho, that
insists that Borrani wire wheels should always be fitted
with the bent-eared version. The straight-eared version
was for the alloy wheels supplied to Ferrari by other
manufacturers. It is certainly true that from an aesthetic
standpoint the bent-eared knockoffs go better with the
Borrani wire wheels.
Perhaps this should have been mentioned when
discussing wheel sizes, but there is a common misnomer
used when stating knockoff (i.e. hub) size. It is common
to refer to these as “32mm,”“42mm,”
or “52mm,” but actually they are simply “type
32, ” “type 42,” or type 52.” Going
back to Mr. Pugh of the Rudge-Whitworth company, he originally
came up with these three standard sizes to accommodate
cars with different size wheel bearings—up to 32
mm, up to 42 mm and up to 53mm.
End of an Era
Ferrari quit using Borrani wire wheels on racing cars
in the mid-1960's, and stopped fitting them to production
cars by the mid-1970's, although on certain models they
had ceased being recommended even earlier. Advances in
technology had resulted in alloy wheels that were not
only stronger but lighter. Finally, the last production
Ferrari to feature the Rudge-type splined hub and single
fixing nut was the Testarossa, which changed over to a
normal five-bolt system in the late 1980's.
