Old Bike Australasia — Issue 68 2017

OLD BIKE AUSTRALASIA: 33

Compression ratio was a healthy 8.75:1 and the
exhaust ports were splayed out, as on the bigger
Dominator engines. Ignition was twin coils and
battery, with twin contact breakers mounted on a
backing plate under a cover on the timing chest. The
familiar Norton oil pump operated in similar fashion
to the bigger twins. A duplex primary chain
connected the engine to the gearbox, running in a
left-side casing that also contained the alternator
which was fixed outside the engine sprocket with
an adjustable block chain tensioner.
Chassis-wise, the navigator broke with established

Norton practice by using a frame made up of several

sections. The frame itself was based on a Francis

Barnett design (Francis Barnett being by that stage

part of the AMC group which also owned AJS,

Matchless and James, as well as Norton. A pressed

steel section formed the front down tube, with the

steering head welded to it. A separate tubular steel

cradle bolted to the steering head and ran over the

top of the engine, down the rear and under the

crankcases to connect to the bottom of the front

down tube. In place of a conventional seat tube, a

steel pressing provided attachment points for the rear

engine mounts, with extra tubes to brace the pivot

for the swinging arm. Most of this was invisible,

being enclosed by a pressed metal shroud. Instead

of the famed Roadholder forks, the front suspension

was sourced from the James/Francis Barnett range,

as were the 6-inch hubs which carried 18-inch rims.

The new Navigator was hurridly completed in

time to make its public bow at the 1958 Earl’s Court

Show, where it graced the Norton stand along side

its big road burning brothers. The reaction to the

new model, with its prissy two-toned colour

scheme, was rather subdued to say the least. Soon

after the show, the first road test reports began to

flow in, and testers were similarly unimpressed with

many aspects of the ‘little twin’. For a start, it tipped

the scales at 330 pounds (150 kg) which was hardly

svelte. Most reckoned the extra weight taxed the

frame, which had thus forth only had to cope with

small (and lighter) two stroke powerplants. The

engine was also a bit on the asthmatic side,

needing a decent handful of revs to coax it into its

comfort zone. However the all-important fuel

economy received a universal thumbs up, with a

figure of 85 miles per gallon being quoted.

The Jubilee plodded along with slight changes

NORTON ELECTRA

Joe Moore Junior, from NSW

Norton agents Hazell & Moore,

goes for a helmetless spin in

Sydney on an Electra in 1965.

ABOVESpeedway star: Dean Hogarth at the wheel.

Left side of the engine is dominated
by the case for starter motor chain.

The Electra engine grew

from the 250cc Jubilee

and the 350cc Navigator.