Norton
Commando 850 Road Test
,Motorcycle
Mechanics June 1973
There's no substitute for cubic inches! The
750 Commando has been the Machine of the Year
for five years running and the 850 is the first
real development of the basic Commando since
it was introduced!
The 850 is very much the same as the standard
Commando with its cycle parts, but it's the
motor which is most interesting. The new iron
barrel has a bore of 77 mm while the standard
750 is only 73 mm. It is simply this increase
in size which gives the extra power.
One of the most important points about the
new motor is the effort Mortons have made to
make it more reliable and easier to ride.
The compression ratio is lower than the 750:
8.5 against 8.9:1 and the carburettor size is
the same at 32 mm. This helps produce not only
more power than the 750 but, very important,
more usable power.
Other firms have produced big-bore kits for
the Commando, but they have never made any attempt
to beef up the bottom end. The 850 is strengthened
considerably where it matters. The four outside
cylinder-head bolts pass through the barrel
and screw into the crankcase. This should reduce
the possibility of the barrel trying to lift
off the cases and also cuts the loading on the
cylinder-barrel base.
The main bearings are what Nortons describe
as "high-capacity, super-blended, large-diameter,
roller main bearings", which apart from
sounding like an advert for margarine means
that the bearings are normal roller bearings
with a slight taper on the ends. This will give
the advantages of the roller bearing for load
capacity and the advantage of taper rollers
for isolating the crankshaft from too much endfloat.
These modifications to the motor should result
in a longer life. But it is not only in this
department that Nortons have been busy. The
crankcase breathing system has been revised.
The breathing is now done from the back of the
timing cover It was found with the old system,
that when the engine was being held at high
revs for any length of time, that a lot of oil
came up the breather and this resulted in a
build-up in pressure in the cases, which caused
oil leaks.
The new breathing system will be more efficient,
and with legislation becoming more strict
about emission control, the new 850 Norton should
have no trouble complying. The silencers, too,
have come in for some development. They are
really quiet and certainly won't give the Noise
Abatement Society anything to complain about.
What's it like on the road? Really good. The
motor is smooth and flexible and there is so
much usable power, I never had any trouble when
overtaking.
The really impressive feature of the motor
is the way it doesn't seem to matter what gear
you're in when you want acceleration. More than
once I managed to get into second gear instead
of first at traffic lights because the gearbox
works the opposite way round to that which I
am used to, but even in second gear there was
no need to slip the clutch to get really good
acceleration.
To find out the standing-start quarter-mile
times, we took the 850 to the Santa Pod Drag
Strip.
We entered the Norton at the season opener
meeting on April 1 and the results were very
impressive. On the day there was a headwind
of between 30 and 40 miles an hour, which was
slowing the times of all the bikes and causing
some of them real handling problems. Fully road
equipped, that means including the baffles
in the silencers, a full tank of petrol and
full toolkit.
The Norton was running in the 13.9-second bracket
all day long, and. there is no doubt, that without
the headwind the Norton would have no trouble
in getting down to about 12.8 or 12.9 seconds.
In a straight race against a 750 Commando,
the 850 was a lot quicker over the first eighth
mile and was still pulling away slightly on
the last part of the strip. I apologise to my
pit crew of Colin Sanders and Denis Gawler and
the Motor Cycle Mechanics fan club for pulling
a red-light in the first round, but I think
the Norton did prove that in standard trim it
has a lot of acceleration, especially as it
was racing against machines, most of which have
been set up especially for Drag Racing.
Although the drag racing session was interesting,
I don't expect the majority of owners are really
interested in a split second difference in standing
quarter-mile times, but I did use the Norton
as much as possible under very varied road conditions—London
rush-hour traffic to deserted twisting country
lanes—and the motor was always perfect.
However, there were one or two minor complaints
about the handling.
On the rare occasion I had to shut the throttle
halfway round a corner, the frame felt like
it was hinged in the middle. And when I checked,
I found that the swinging arm had enough play
in it to fail the MoT test.
When Charles Deane rode the bike, he thought
the front end was too light and, if the power
was put on hard going round a corner, the front
wheel became light enough for the bike to want
to go straight on. Charles and I are about the
same size and weight and yet I had no problem
with a light front end, which either means that
we ride a bike differently or, more likely,
that "the Ed" goes a lot faster than
me!
I used the bike quite a bit for night riding,
and fortunately our model was fitted with a
quartz halogen headlight. This light was so
good that I would not consider buying a Commando
without one.
Although I really enjoyed riding the Norton,
both the editor and I have two identical complaints.
The first is that the seat is far too high,
and although it only measures 32 in. off the
ground, it's so wide it feels more like 36 in./
It would be no problem for Mortons to lower
the seat on this bike as there is enough room
for it to be dropped at least 2 in. All that
needs to be done is to make a new seat base.
The other complaint is also caused by the seat
height. The only way I could get a good swing
on the kickstarter was with the bike on the
centre stand. When I tried to start it off the
stand, it turned into a Sammy Miller balancing
act, with the likelihood of me and the bike
toppling into the gutter!
Once underway, the height doesn't matter, in
fact the riding position is really good. The
footrests are high and the tank is wide enough
to grip comfortably between the knees. Also,
the seat is well shaped to stop even weak-armed
riders like me from falling off the back.
With its fantastic, performance, the Norton
would be dangerous if it didn't have the brakes
to match. The front was deceptive, because it
had a very wooden feel. However, it never locked
the wheel and I never felt that there was any
chance of the bike not stopping in time.
The lack of feel could probably be overcome
by giving the brake slightly more leverage,
at the same time providing a method of adjusting
the gap between the lever blade and the handlebar.
The back brake is superb. The design is the
same as that used on Mortons since the days
of the Featherbed Dominators. Odd to say, but
in those days it never used to work particularly
well and, although there are no obvious improvements,
the brake is very smooth and does not suffer
from fade no matter how hard it is used.
Neither the clutch nor gearbox could be
faulted. No matter how much the clutch was slipped
it always took up the drive cleanly. Gear selection
was always positive and never once did
I miss a gear, even when I did clutchless changes.
This is one bike that does not need the complication
and expense of a five-speed box.
Nortons are the only firm still making a gearbox
with a one up three down pattern and this can
cause confusion. Perhaps it is time they changed
the pattern to be the same as other manufacturers.
This new Commando would be my choice for the
"Machine of the Year" if it wasn't
for so many points of criticism over quality
control. Maybe our model had been badly treated
by whoever had tested it before, but we
had considerable trouble during the first week
we had the bike.
One of the bolts which holds the inner chaincase
to the crank-case had come undone because its
tabwasher had not been properly done up.
The bolt had smashed its way through the inner
chaincase When we took the outer cover off,
there was an even bigger horror inside. Somehow
the triplex primary chain had only been fitted
to two runs of the engine and clutch sprocket.
I would have thought it impossible for
the chain to have jumped a complete row of teeth,
which means the chain must have been put on
wrongly.
We are never sure if the bikes supplied to
us for road test are the best of the range or
if the manufacturer cleans up a development
model just enough for "mad" journalists
to wreck. But if the Commando was supposed to
be a good example of this model, then Mortons
have some rethinking to do on their quality
control.
Within 1 500 miles our Norton was starting
to look very second hand. We had rust on the
cylinder-head bolts, rust on the barrel and
on the centre of the front disc.
The exhaust pipes had turned a very attractive
shade of blue and the motor was running slightly
rich. In places, the frame appeared to have
no paint on it. The cross tube under the motor
and the front engine mounting had started to
rust.
Would I buy one? Yes, if someone will buy my
Drag bike off me at the right price. The idea
of having a bike which is quick enough to be
competitive on the strip and the occasional
clubman's road race and still be able to use
it for touring and about-town transport, makes
the Norton my sort of motorcycle . The rear
chain oiler had lubricated everything from the
pillion footrest back, except the rear chain.
There was no possibility of the nearside front
fork leg rusting, there was too much oil leaking
for that to ever happen and the white lining
and top layer of paint on the back of the fuel
tank had been worn away by the riders' knees.
All this on a very expensive motorcycle
which should be an advert for the quality of
British engineering. It's not good enough!
I like the Norton, but if they are hoping to
sell this new model to anyone apart from founder-members
of the Norton Owners' Club, they are going to
have to crack down on the standard of workmanship.
The design is very good, it combines the best
of the traditional; separate gearbox, a reliable
fuss-free motor that is easy to work on, with
enough new features to make it an attractive
bike. But who wants to buy a new bike and have
to spend time working on it instead of riding
it?
Specifications;
Engine: Twin-cylinder pushrod-operated
four-stroke. Bore 77 mm, stroke 89 mm, giving
a capacity of 830 cc. Compression ratio
8.5:1. Power output 60 bhp at 5800 rpm. Maximum
safe revs 5900 rpm for continuous cruising.
Transmission: Four-speed constant-mesh
gearbox with ratios 11.20, 7.45, 5.30, 4.38.
Primary-drive ratio 2.19:1. Multi-plate
diaphragm clutch with triplex chain drive. Carburation:
Twin AmalCon-I centric 32-mm-borecarburettors.
Wheels: Front: 4.10 X 19 with
10.7 in. hydraulic disc brake. Rear: 4.10 X
19 with single-leading-shoe 7 in. drum brake.
Suspension: Front telescopic forks. Swinging-arm
rear suspension with adjustable rear dampers.
Dimensions: Fuel tank 5 gallons
with f-gallon reserve. Oil tank 5 pints. Weight
430 Ib. Seat height 32 in. Length 88 in. Price:
£726 inc. VAT. Manufacturer: Norton Villiers
Ltd, Andover, Hants.
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