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jueves, 18 de julio de 2013

Rolex Explorer Ref. 14270 - by replica de relojes


REF. 14270

Explorer, medium close dial
Explorer 14270

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 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 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.



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 fillthe 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 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).


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.