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►To the person who spends most of his riding
hours tooling about on the lightweight machines that currently dominate the
market, a ride around the block on the new Royal Enfield 750 Interceptor can be
something of a shock. The sheer brute power of the thing might actually be
scary, were it not for the excellent handling qualities and sure-footedness
which the machine also possesses.
Even experienced riders of motorcycles of 650cc displacement and up are
surprised by the length of the power range. It is entirely possible, for
instance, to putt-putt along at (say) 5 mph in second gear, then suddenly turn
on the steam and arrive at the 70 mph mark about nine seconds later without
having shifted a gear. In this sense, it's a kind of Bugatti of the motorcycle
field.
The acceleration curve of the
Enfield powerplant that some tend to call old fashioned is practically flat from
0 to 70 mph. Only after 70 does the eye discern any appreciable arc on the
graph, and even then, with prudent shifting at 40, 67 and 85, one reaches 100
mph in just over 21 seconds. Top speed of 115 mph, under optimum conditions,
would require nearly a full minute elapsed time.
What places Enfield's offering
into the "old fashioned" category is the long stroke (93mm) and individually
cast cylinder barrels. Today's cycle buyer has become accustomed to unit engine
construction and thinks the design must be nearly oversquare to be any good.
In point of fact, oversquare,
under-square and perfectly square layouts all have their benefits, depending on
your point of view; but generally speaking, the longer the stroke, the more low
end torque you get, especially when you are dealing with only one or two
cylinders. Big automobile engines can overcome a tendency toward poor torque at
low speed (engendered by short stroke) by having many cylinders in operation at
once. When you are dealing with only two cylinders, you can go only one way or
the other.
When it is considered that the
Interceptor's acceleration curve is practically a straight line to the legal
speed limit, that despite reduced torque above this speed it will cruise easily
at over 100 mph, and that the engine can be operated at any rpm without
vibration, one must conclude that the Enfield engineers did well.
As for unit construction,
everyone knows this is purely an economy measure. Casting the two barrels
together and capping them with a single head is clearly less expensive than the
older system. But it has disadvantages.
For one thing, cooling between
the cylinders is reduced. A flow, of fresh air between the barrels assures even
cooling and reduces the likelihood of warping under intense heat. And for
another, down time is reduced in the event a repair is needed on one cylinder
but not the other. It can be somewhat aggravating to have to dismantle the
entire upper engine, for instance, to replace one broken piston ring.
The R-E engine, in short, is a
very impressive piece of machinery. There were no shortcuts taken in its design
and manufacture, and as a result, the factory foresees no significant changes in
the next few years. Unlike some of the more competitive models on the market, it
was built from bottom to top as a 750, complete with the necessary strength at
the bottom end.
A slightly modified model,
available now for the first time, indicates a possible new market emphasis for
the Enfield Company. This is the Custom Police Interceptor, identical to the TT
Interceptor, except that it sports a larger gas tank (4 gal.) and lower
compression ratio (7.5:1). The lower compression does much damage to the top
speed, but facilitates smoother low speed running.
While Harley-Davidson gets
nearly all the police business in this country, apparently the Enfield Company
feels they can present serious enough corn-petition to bite out a chunk of the
market, and they may be right.
For long-time riders who have
noticed the Enfield marque appear, disappear and reappear on the American market
since the end of World War II, we recently obtained the straight scoop from the
factory.
Enfield began sending bikes
over here under their own nameplate in 1946 and continued through 1954. For the
next five years the Indian Company, which was owned by Brockhouse of England,
bought Royal Enfield motorcycles with the Indian name on the tank and sold them
as Indians in the U. S.
In 1959 the Indian name was
bought out by Matchless, ending the association of Enfield and Indian, except
for a few Indian Chief 700s sold in late 1959 and early 1960. At no time did
Enfield own Indian, or vice versa, and indications are that there will be no
more Enfield Indians. For the past five years the Royal Enfield has been
imported directly by four major regional distributors■ |
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