The BeckerTime ‘Firsts’ Series: The Rolex Caliber 3135

There have been a number of movements created by Rolex over the years which have become almost as legendary as the watches they drive.

In previous articles we have looked at the likes of the Cal. 4130, the brand’s first ever in-house chronograph caliber which elevated the Daytona to never before dreamt of heights, as well as its predecessor, the Cal. 4030 based on Zenith’s El Primero, which set the Cosmograph on its path in the first place. Elsewhere, we detailed the Cal. 1030, Rolex’s debut domestic automatic movement, along with the Cal. 3035, their short-lived initial high beat mechanism.

For this post, we are going to explore that caliber’s successor—not only the manufacture’s longest-serving and most widely used engine, but a genuine benchmark moment in horology in general; the Cal. 3135. We’ll give a quick breakdown of just what made it so important, and list which year it was installed into the various Rolex models.

The Cal. 3135

Only a little over 10-years after the Cal. 3035 came into service, Rolex set about replacing it with a whole new generation of movements. The incoming Cal. 31XX series of calibers, headed by the time-and-date base engine, the Cal. 3135, addressed a number of issues which Rolex felt they could optimize. 

Firstly, the new movement was thinner than the Cal. 3035, shrinking from 6.3mm to 6mm, leading to correspondingly slimmer watches. In addition, the improved winding system of the Cal. 3035 was improved again on the Cal. 3135 with the introduction of a larger and better balanced rotor, which was also quieter—some people reported that the winding on their Cal. 3035 watches was relatively loud compared to other high end watches.

In addition, refinements were made to the gear train and escapement for better performance, and the balance wheel became more supported, and so more stable, through the use of a balance bridge supported at both ends rather than the Cal. 3035’s balance cock. And finally, a redesigned mainspring barrel upped the power reserve again, going from 42-hours to 50. 

All in all, the string of seemingly minor developments all added up to a major advance, an overall more streamlined modular design loved by watchmakers and technicians and the Cal. 3135 stayed in use across much of the Rolex portfolio right up until 2022, having served with distinction for an incredible 34-years. 

During that protracted run, the movement and its various offshoots were continuously tweaked and refined. The Parachrom hairspring was added in 2000, a next gen component cast in a patented alloy which shrugged off temperature changes and magnetic fields. In 2005, the old Kif shock absorbers were swapped for Rolex’s own Paraflex ones, and all throughout the caliber’s term improvements were made to the lubrication oils the brand used. 

And, surprisingly, right at the very end of the Cal. 3135’s service, the Chronergy escapement was added, an element more associated with the contemporary Cal. 323X series. 

Although sometimes disparagingly described as a workhorse caliber, there’s no doubt that the Cal. 3135 remains one of, if not the, best mass-produced watch movements ever made; the end result of more than 80-years of Rolex’s obsessive quest for perfection in creating the ultimate timekeeping device in terms of both accuracy and resilience. 

Below, we list the models, references and years in which the Cal. 3135 was put to work, along with its derivatives; variations on the caliber with added or subtracted complications which were fitted into the rest of the collection. 

Cal. 3135

Cal. 3136 (Slightly Larger Version to Fit Inside the Datejust II)

Cal. 3130 (No Date Version)

Cal. 3132 (Slightly Larger No-Date Version)

Cal. 3131 (Antimagnetic Version)

Cal. 3155 (Double Calendar Version)

Cal. 3156 (Slightly Larger Double Calendar Version to Fit Inside the Day-Date II)

Cal. 3185 (GMT Version)

Cal. 3186 (Upgraded Version of the Cal. 3185 w/Parachrom Hairspring)