Among
the watches in Rolex’s current production, the Oyster Perpetual Explorer
(Ref. 14270, but known popularly as “The Explorer 1″) stands in the
lower-middle segment of the stainless steel line: a COSC certified center-seconds
caliber 3000, without date, retailing for approximately $2,500. The
Explorer is also, perhaps, the most historically connected model in
the line, deriving from a long line of very similar Explorer designs.
The watch is supplied in a 36 millimeter steel “Oyster” case, with an
attached steel “Flip Lock” Oyster bracelet. The case is approximately
11.5 millimeters thick.

THE DIAL AND CASE

The relatively simple three piece case (bezel, band,
and back) is clearly strong and rigid. (Rigidity is an important issue
in maintaining water-resistance in use that involves impact that
can distort the alignment of the case.) While the bezel and band sides
(which are integral with the strap lugs) are polished, the upper horizontal
surface of band and lugs is brushed. The brushing shows a slight unevenness
on the case band, especially between the lugs and should be more consistent
in a watch of this cost. The polished sides of the case, however, are
an unusual, peculiarly appealing double-horn shape characteristic of
many Rolexes, and are
sumptuously polished so that the metal has almost the luster of white
gold (right). The uncoated sapphire crystal, as can be seen,
is set largely outside the bezel. The internal surfaces and backs of
the lugs are not as well finished as the top and side surfaces, and
even with the bracelet in place, the inside lower lug edges and tips
are uncomfortably sharp (below left). They should be slightly
radiused to eliminate this unpleasant feel. The completely unadorned
back is nicely brushed,
and shows the familiar Rolex serrated wrench ring (yellow arrow,
left).

This back design requires a special bit that matches
the serrations on the back. The Bergeon bit for the Rolex (#5, 29.5
millimeters) is shown below right. The Rolex system is perhaps
the finest screwed back design in production. Used properly, it allows
removal–and reattachment–of even the tightest backs without the slightest
visible mark left on the watch. Most designs–with holes,
slots, or hexagonal protrusions–are nearly impossible to use without
some visible evidence left behind. To be properly used, however, the
Rolex wrench and back must be perfectly parallel and stable, and this
generally requires a true case opener, rather than a hand wrench. The
Bergeon 5700 opener, as shown below left, clamps the watch firmly
in a horizontal position between two rigid nylon blocks
and allows the bit to be lowered onto the watch in perfect alignment.
It is a shame that other manufacturers do not use similar designs. The
design does not, however, lend itself to the use of hand wrenches with
the watch improperly supported. The many scratched Rolex backs that
watchmakers report are undoubtedly due to the use of unstable and poorly-aligned
hand wrenches.

THE DIAL

The black enameled dial of the Explorer is elaborated
with a painted white minute track, white gold bar markets filled with
tritium, and white gold Arabic numerals at three, six, and nine. The
tritium-filled hands are also made in white gold.
To my tastes, the markers and hands are oversized and give the dial
a cramped and busy appearance. The flat, uncoated sapphire also causes
strong reflections that add to the difficulty in easily reading the
time. Taste aside, the dial and hands are detailed, extremely well made,
and immaculately finished. I would imagine that, together, they represent
a significant portion of the manufacturing costs of this watch.

THE BRACELET

For
a watch that it is in some ways about its steel bracelet, it
is remarkable that this bracelet looks so much like an after-thought.
The beautiful case shape and lugs–which were clearly originally designed
for use with a strap–are visually almost completely destroyed by the
bracelet. Furthermore, the bracelet is not only unintegrated with the
watch aesthetically, but physically as well. It is attached to the lugs
with standard springs bars (as if it were a strap), and an “insert”
is placed between bracelet and case to fill
the space between the two. The insert hangs on the spring bar; two awkward
(and exposed) tabs behind the lugs stabilize it. Despite the insert
having a single purpose–to fill the space between the lugs–it does
so very crudely, following neither the contour of the case, nor the
lugs. The design and fit is as awkward and unattractive as anything
I recall seeing on a production watch. The clasp for the bracelet is
comprised of stamped steel pieces that feel cheap, and seem obviously
inappropriate in a watch of this cost.

THE MOVEMENT

The
Explorer houses a Rolex caliber 3000, a 12.5 ligne (28.5 millimeter)
5.8 millimeter thick, 27 jewel, 28,8000 BPH automatic. Although the
movement is largely conventional in design, there are a few unusual
design features.

The bidirectional automatic winding system is similar
to the ETA/Eterna system in using a pair of double-click wheels for
winding reverse. (For an explanation of how this system works, see the
Horologium article “Anatomy of an $85 Watch: The Swatch Automatic.”)
The two “red” wheels appear to be fabricated of a light alloy, and are
coated with PTFE (“Teflon”) for lubrication of the outer teeth and inner
clicks . Shown right, the
upper PTFE-coated wheel can be seen inverted at the blue arrow,
the inner-lower wheel at the yellow arrow. (The red arrow
indicates the transmission wheel for hand winding.) Because both upper
wheels rotate continuously during movement of the winding rotor in such
a double click wheel system, the large size of the wheels may have dictated
the light alloy to reduce their mass and thus improve winding efficiency.
The alloy is probably also quieter in operation that steel parts would
be. I do not know whether the PTFE coating provides the durability that
conventionally lubricated steel parts would offer. The automatic winding
system is the single best-finished part of the movement.

A
clever, efficient and cost-saving design solution is also seen in the
mounting of the winding rotor shaft, illustrated at left. The
top of third wheel jewel has an oddly shaped recess that supports the
bottom pivot of the rotor shaft. Thus, a single jewel supports the third
wheel from above and the rotor from below. A possible shortcoming in
this arrangement might be that a significant shock to the watch would
cause the considerable mass of the rotor to displace the friction-fit
jewel and disturb the third wheel pinion end-play. The rotor shaft is
secured to its mounting in the automatic winding bridge only by a circlip,
and shows considerable side-play in operating position. I am told by
naturalsizeflag=”3″ alt=”Rotor and automatic winding bridge”>Rolex
service people that this is a not uncommon source of trouble in the
otherwise sturdy winding system. The simplicity and over-sized design
of the automatic winding system characterizes the entire caliber 3000.
The well-finished rotor, inverted and attached to the winding bridge,
is shown at right.

The only other unusual design feature of the caliber
3000 is the use of a flat (i.e. without overcoil) hairspring
without a regulator and an extremely simple version of an adjustable-mass
balance, illustrated below left. The green arrow indicates
one of the four screws used to provide adjustment of the center of mass
of the balance and thus control the rate of the watch. What at first
appears to be a regulator (yellow arrow) is, in fact, simply
a movable balance spring stud to allow easy adjustment of beat. The
Glucydur balance with four screws–called a Microstella balance by Rolex–
provides an extremely
simple solution to rate regulation that is also, undoubtedly, less expensive
than a conventional regulator. By contrast, the conceptually similar
Gyromax balance of Patek Philippe is a refined and expensive system
with eight top-mounted rotating, slotted weights. Both systems offer
the advantage of not introducing the adjustment complications of a regulator;
but both also make simple rate adjustments a more complex and time-consuming
task. The Patek system, however, makes screwdriver access (to rotate
the weights) from above an easy matter. The Rolex system relies on rotation
of the serrated screw heads from the side, presumably with a screwdriver
blade, unless the balance is removed from the watch (in which case a
special “star” wrench could be used). Judging by the significant damage
on all four screws (due to adjustment at the factory), this is not an
easy task, at least if it is to be accomplished without damage. (Enough
metal had been gouged from the screw heads in this movement that balance
poise may well have been affected, damage that would not necessarily
appear in the timing figures, but might make future timing adjustments
more difficult.) This photograph also illustrates the KIF shock protection
for the escape wheel (blue arrow).

PERFORMANCE

On the electronic timer the Explorer showed excellent
performance, in a class with many top-notch watches. In the adjusted
five positions it showed a daily variation of three seconds per day
between the fastest and slowest positions (plus one second crown left
and crown up; minus two seconds dial up and dial down). A five second
variation on this parameter is a widely accepted standard for high quality,
fully adjusted watches. Dial up and dial down readings were virtually
identical in terms of rate, beat, and amplitude (a good measure of the
condition of balance pivots and vertical centering, or flatness, of
the balance spring). The unadjusted position, crown right, was well
within the parameters of the adjusted positions at minus two seconds.
In daily use, the watch turned in a good, if not outstanding, performance,
losing about three to five seconds in various measured 24-hour periods.

Assuming
a lift angle of 52 degrees (Rolex Service in New York would not supply
me with this figure which cannot be readily determined from the watch
itself), the amplitude was more than adequate, though not exceptional:
294 degrees in horizontal positions, and 244 to 259 in the various vertical
positions. Very fine, well-serviced watches usually provide 310 degrees
or better in horizontal positions, 260 or better in vertical positions.
Amplitude is a measure of the total efficiency of the movement, and
good amplitude is essential to positional adjustments and rating.

Beat error fell between zero and 0.3 milliseconds
in the various positions, a good performance. Unfortunately, the lowest
beat errors were adjusted into the least critical positions, crown up
and crown right (both zero). This put the dial up position at 0.2 and
the crown down position at 0.3 milliseconds error, positions in which
one would normally seek the least error. My only other concern about
timer performance is in the intermittent beat error indicated at the
blue arrows and inset in the tape illustrated above. While
slight variations in beat (in any given position) are almost always
apparent in most watches, the error in this watch was an almost perfectly
regular, rhythmic error that suggests an irregularity in the escape
wheel–possibly an out-of-round condition or a damaged or malformed
tooth. Without counting escape wheel teeth (there are more than the
usual 15) and timer ticks, I could not be sure of this relationship.