This year a new class is introduced
for the world championship races: 50 cc, and Honda decides to participate.
Furthermore they participate in the 350 cc class. In the 50 cc they
are not successful, the two-strokes are simply faster, but the other
three classes yield three individual world titles and three constructor's
world titles. The works riders for 1962 are Redman, Phillis, McIntyre,
Tanaka, Takahashi and Tommy Robb. Phillis crashes fatally during the
350 cc race on Man while in pursuit of the MVs of Hocking and Hailwood.
This causes Hocking, a personal close friend of Phillis, to stop motorcycle
racing. He returns to Rhodesia, and is killed when practising for
a car race. Later in the season Bob McIntyre is killed in a crash
during a national race in England on a Norton. The 50 cc world title
is won by Ernst Degner on Suzuki, Hans Georg Anscheidt is second with
Kreidler, and Taveri comes in third. The 125 cc title goes to Taveri,
with Redman and Robb in second and third place. The 250 cc world title
is for Redman, with McIntyre second, and the 350 cc crown is also
for Redman, with Hailwood (MV) second, and Robb third.
cc RC110, 111 and 112
The RC110 is a single cylinder with a
bore and stroke of 40 x 39, dimensions which are nearly the same as
those of most of its competitors. The two over head camshafts are
driven by a gear train on the right hand side of the engine. The cylinder
is inclined 35 degrees. The valve angle is the same as for the 125
and 250 cc Hondas, i.e. 36 degrees on the inlet and 40 degrees on
the exhaust side. Ignition is by crankshaft mounted generator and
HT coil, with the contact breaker points mounted on the inlet camshaft.
Compression ratio is the by now well known 10.5 : 1 and output is
9.5 bhp at 14,000 rpm. Wet sump lubrication. The bike was developed
together with a street version, which explains the five speed gear
box and a plugged kickstarter shaft opening.
This five speed gearbox is already replaced
with a six speed cluster when the first GP of the season is held.
For the French GP, the bore is increased to 40.4 mm, which brings
the capacity to 49.9 cc. The machines used on Man are designated RC111.
They have redesigned crankcases, an eight speed gearbox and the inlet
length is greater, with a long intake rubber
1962 50cc RC110 Honda
For Assen the bike is provided with a ten speed
gearbox, but for the race Taveri prefers the eight speed version
- in Finland he uses a nine speed cluster. The last race of the
season is held at Suzuka, and here the RC112 makes its debut and
also runs its last race.
1962 50cc RC112 Honda
1962 50cc RC111 Honda
The RC112 is a twin, with bore and stroke of 33
x 29 mm, giving a total capacity of 49.6 cc.
There are 2 valves per cylinder. Ignition is
by magneto and still works with contact breaker points (!), lubrication
is with wet sump system, and the gearbox is nine speed.
Power is given as over 10 bhp at 17,500 rpm, torque is 0.45 kgm
at 15,000 rpm. Dry weight is 62.5 kg.
Tommy Robb wins the race, giving Honda its only 50 cc win of the
The RC145 is directly derived from the four cylinder RC162,
with the drive to the camshafts now by a gear train, taken from
the centre of the crankshaft. In principle it's a four without the
two outer cylinders. Bore and stroke are still 44 x 41 mm.
The only difference with the four apart from the number of cylinders
is the lubrication system, which is wet sump. Power is 24 bhp at
14,000 rpm. Dry weight is 103 kg, and as top speed over 180 km/h
This shows a bike being restored in Honda's restoration workshop
in the Honda Collection Hall.
The RC163 has some small changes, the most obvious
one being larger cooling fins for the cylinders.
Internally the engine is the same. Power output
is now 46 bhp at 14,000 rpm.
cc RC170 and 171
The 1962 350cc RC171 Honda
Honda first competes in the 350 cc class
on Man, with a 250 four cylinder bored out to 47 mm, giving 285 cc.
The bike delivers 50 bhp at 13,500 rpm. Later, a new bike,
designated RC171, with bore and stroke of 49 x 45 mm, giving a total
capacity of 339.4 cc, is developed, used for the first time at the
Ulster GP. Power output is 56 bhp at 12,500 rpm. Since there are some cooling problems, the bike gets an oil cooler
behind the exhaust down pipes. Later, after some small changes, the engine is thermically OK,
and the oil coolers are taken off again.
1962 was the year that saw the introduction
of the Honda production racers, the 50 cc CR110, the 125 cc CR93,
the 250 cc CR72 and the 305 cc CR77.
1962 50cc CR110 Honda
The CR110 was, except for the colour
scheme, virtually identical to the first RC110, complete with five
speed gear box and blinded kickstarter shaft hole. Here, too, the
five speed gearbox proved inadequate, and was changed to the eight
speed version. Contact breaker points are now mounted on the right
hand crankcase cover, forward of the clutch. The claimed power was
8.5 bhp at 13,500 rpm, maximum torque 0.46 kgm at 11,500 rpm. Dry
weight was 61 kg.
The CR 93 was also derived from a street bike, hence the blinded
kickstarter shaft hole. The twin had a bore and stroke of 43 x 43
mm for a total capacity of 124.8 cc. Drive to the camshafts was
by gear train on the left hand side of the engine.
Compression ratio 10.2 : 1. Ignition was by crankshaft mounted
generator with external HT coils; the contact breaker points were
mounted on the inlet camshaft.
Wet sump lubrication, with, as an inheritance from the street
bikes, had a rotating oil filter. The gearbox had five speeds.
Claimed power was 16.5 bhp at 11,500 rpm, but it was a well
known fact, that most of these little gems were much more powerful
Many times Dutch champion Cees van Dongen's CR93 had approximately
22 bhp. The early types had a double sided, single leading shoe
front brake, the later types a single sided 2ls brake.
The CR93 was a very popular bike, not only for its speed and
handling, but also for its legendary reliability and longevity.
The CR72 was a twin with a bore and stroke of 54 x 54 mm, for
a total capacity of 247.3 cc. Compression ratio 10.5 : 1. Ignition
by crankshaft mounted generator with external HT coils and contact
breakers on the left hand crankcase cover. Wet sump lubrication.
Six speed gearbox. Power output 41 bhp at 12,000 rpm. See pic. CR72.
The CR77 was identical to
the CR72, but with a bore of 60 mm. Power was 47 bhp at 12,000 rpm
These two types, the CR72 and CR77, remain something of an enigma
Contrary to the CR110 and CR93, they were not developed from
or in parallel with similar street bikes. Furthermore they came
in a bewildering variety.
First the engines, which were identical, except for the bore.
But, there were at least two types of engine.
One was rather smooth, with light alloy covers the other type
more cluttered, with magnesium covers. Some engines of type 2 have
external oil return lines from the exhaust camshaft housing, which
is clearly visible in the pictures, and mounting lugs for frame
front down tubes.
1962 305cc CR72 'smooth'type
1962 305cc CR77 'cluttered'type
Furthermore, there has been a prototype with chain drive to
the camshafts, but this model obviously never went into production.
< ..... See pics at right
1962 305cc twin front down tubed frame
1962 305cc open double loop type frame
The frames came in four types:
305cc twin front down tubes frame
1) the spine types akin to the ones used by the CR93, as already
2) some types with twin front down tubes this bike has no external
3)the open, double loop type as used on the works racers
4)and a kind of combination, with a central tube under the tank,
twin down tubes to the swingarm bearings, and twin front down tubes
Roy Bacon, in his book "HONDA - the early classic motorcycles",
states that the CR72 and CR77 were derived from the factory twins
- CR250 and CR305, which are the ones with the type 2 engines. However,
I've never been able to find any reference anywhere else to those
CR250 and CR305 types, and even the chief Honda restorer in the
Honda collection hall knew nothing about them.
My own type 2 engine was stamped CR77.
CR72's and 77's were, contrary to the CR110 and 93, never sold
to the public. They were used by the works riders during 1963 (about
which of course more later), and from them were gradually dispersed.
My own CR77 was left behind in parts at Schiphol airport by
the Japanese team upon return to Japan, and never picked-up - Dutch
customs sold it afterwards.
For some uncomprehensible reason, Honda now state in their documentation,
contrary to their claims of 1962, that the CR72 had 25 bhp. That
is of course ridiculous, it would mean less power than the NSU Sportmax
of 1955, a pepped-up standard bike, a single with SOHC and two valves,
had. So, why did Honda make these twins in the first place? Not
to sell them to the public. As a cheap alternative to the fours
for the works riders? Hardly. The cycle parts were nearly identical
to those of the fours, so that would give no difference in price
- and to design, build and develop completely new twin engines with
all its necessary new dies, moulds and tooling would probably just
as expensive as making a couple of four cylinder engines, or at
least make a lot of spares. So, again, why?