Although we rarely feature them in the Japanese edition of Chronos, the Chronos editorial team is a big fan of Rolex. They are robust, highly accurate, and highly legible, with striking exterior finishes and affordable prices. While we have many favorite models, my personal picks would be the Oyster Perpetual Cosmograph Daytona and the Oyster Perpetual Explorer, commonly known as the "Explorer I." Both retain the fine qualities of Rolex and are especially comfortable on the wrist. I've always considered the Explorer (114270) featuring the legendary 31 series movement to be the best. The new Explorer (124270), released in 2021, is reminiscent of the 114270. While some have criticized it as too safe and uninteresting, it's refreshing to see the return to a 36mm diameter and the return to a desirable package.
Text by Masayuki Hirota (Chronos-Japan)
Article published on June 2021, 4
The history of modern Rolex, beginning with the 3000 series
In my opinion, the modern Rolex era began in the late 1970s with the release of the 3000 series (such as the 3035 and 3000). This movement, in addition to featuring a robust and highly efficient automatic winding mechanism adapted from the 1500 series (1570), was the first Rolex movement to feature a center fourth wheel rather than a leading wheel, allowing for a center seconds hand. The 3000 series also featured a "modern" structure, integrating the automatic winding and base movement rather than stacking the automatic winding module on top of the base movement. Furthermore, the frequency increased from 19,800 vph to 28,800 vph, significantly improving watch accuracy.
The Explorer (14270) was equipped with this caliber 3000. Perhaps to keep costs down, the balance spring was a flat one rather than a wound one. However, to differentiate it from the Air-King, it was equipped with a movement that had been certified as a chronometer.
The 3100 series was a version of this movement with modifications, mainly to the calendar. It was released around 1988. At the same time, the case material was changed to what Rolex calls Oystersteel, or 904L, further enhancing the watch's perfection. This movement was installed in the Explorer (114270), released in 2001. While it looks almost identical to the 14270, the bracelet was heavier, improving balance with the head, and the hairspring was changed to a winding hairspring, resulting in outstanding portable accuracy. Until the new 124270 was released, this was the best Rolex I had ever owned.
The head is now heavier, and so is the bracelet.
When it comes to cases and bracelets, Rolex has been playing a game of cat and mouse for the past 40 years. The original 3000 series models, like the 1500 series models, were characterized by their light and comfortable feel. This was partly due to the lightweight plastic crystal. However, the later change to a heavier sapphire crystal made the head of the Professional model heavy. To balance the heavy "head," a sturdy bracelet or a flush fit was required.
This was made possible by Rolex's move to manufacture exterior components since 2000. By manufacturing bracelets in-house, in particular, Rolex models were finally able to restore the proper weight balance between the head and tail. While this in-house manufacturing significantly improved the quality of the exterior, it's undeniable that the watches have become heavier as a result.
One-piece case construction leads to increased weight
The unique case structure was also a factor in the weight of the head. In ordinary watches, the movement is fixed to a middle frame (movement holder) built into the case. In contrast, Rolex watches from the 1500 series onwards integrated the case with a spacer, and the movement was mounted there. This is what Rolex calls a "monobloc middle case." The reason for omitting the spacer was probably to make the case more robust. Shocks would be transmitted directly to the movement, but the free-sprung balance adopted from the 1500 series onwards reduces the negative impact on accuracy.
This was a very logical design, but the construction meant that the head tended to be heavy. This wasn't a problem in the past, but since the 2000s, when Rolex began increasing the size of its cases, the weight of the head has become noticeable. However, by making the bracelet heavier, Rolex has been able to maintain the balance of the watch. This skill in finding the right balance is truly Rolex.
A bit of a digression: As the overall weight of the watch increases, it becomes more difficult to keep the bracelet loosely wound. As a result, some Oyster Perpetuals now have extensions built into the clasp. In my opinion, the lighter the watch, the less necessary the extension.
