While Rolex calls it an Oysterflex bracelet, this is in reality a high-performance elastomer strap with flexible metal blades in its core. The Rolex Yacht-Master’s Oysterflex bracelet was developed and patented by Rolex using a high-performance elastomer over-molded over a flexible titanium and nickel alloy metal blade. To provide higher resistance, the metal blades are located within the areas where the strap connects to the case and to the clasp.
The Rolex Oysterflex bracelet/strap is equipped with an Oysterlock safety clasp that prevents accidental opening. Opposed to what Rolex states on its website, the clasp doesn't feature the Easylink system link that allows the wearer to extend the last link. However, micro-adjustments are still feasible by moving the solid link throughout the three small holes on the interior of the clasp.
Without a doubt, the biggest design flaw of this bracelet/strap is the fact that, unlike the strap on the Patek Philippe Aquanaut, the Rolex Oysterflex bracelet cannot be sized to an exact fit. While on the Aquanaut, one would cut the strap to the exact length as necessary, for the Rolex Oysterflex bracelet/strap, one needs to get fitted for the right strap size while purchasing the watch at an authorized dealer. Of course, some grey dealers might also offer the possibility.
The way the Oysterflex is properly sized prevents the owner from making additional adjustments after the purchase, but it is also impossible for anyone else with a bigger or smaller wrist, to borrow the watch or try it on. Also, this is a big problem and one thing to keep in mind for those wanting to purchase this watch in pre-owned condition in the secondary market.
For enhanced comfort, the inside of the Oysterflex bracelet is equipped with a patented longitudinal cushion system that stabilizes the watch on the wrist to prevent it from turning around and remaining centered on the wrist. The cushion system membrane is extremely smooth to the touch and very comfortable, it also allows for the watch to feel more comfortable in case the wrist swells up during those hot summer days.
Now I will explain how one can properly size the Oysterflex bracelet/strap. There are six different sizes in total for the Oysterflex strap segments —one is missing in my picture. Regardless of the case size of the watch fitted with an Oysterflex bracelet/strap —all case sizes have different lug sizes— all Oysterflex strap segments are identical in length. To avoid multiple trips to an AD, just make sure you get the right width if you are trying to replace the strap on a pre-owned watch you just purchased.
The codes for the strap segments are the following: 350557 for the Yacht-Master 37 and 350501 for the Yacht-Master 40. Underneath these codes, you will find a set of two letters that start with the letter 'E'. The second letter on that code dictates the length of the strap segment —from 'C' to 'H'. Since there is no 12 or 6 o'clock side on the Oysterflex, the strap segments can be used on either side of the case and two different sizes of segments are usually combined —shorter at 6 and longer at 12— to get the best fit and to keep the clasp centered on the bottom of your wrist.
For those of you interested in buying pre-owned Rolex watches equipped with Oysterflex bracelet/strap, think about it twice. Now, if you end up doing it, always make sure to ask the seller what the double-letter code is on each segment of the Oysterflex bracelet. Otherwise, you'll have to spend $320+ USD for each segment/side you have to replace —$640 USD for a full new strap.
To make things easier on you, we are including the size of each segment per the measurements we took at an AD. We measured from the hole where the spring bar connects to the case to the hole where the screw connects to the Oysterflex solid link that goes into the clasp. The measurements are approximate at best, as unfortunately the information on the exact length is not available on the Rolex parts database.
The codes are EC-4cm/1.57", ED-4.5cm/1.77", EE-5.5cm/2.16", EF-6.5cm/2.56", EG-7.75cm/3.05" and EH-9.0cm/3.54". i.e. A typical combination on a Yacht-Master 37 on an average lady's wrist would be an ED at 6 and an EE at 12 o'clock. For a Yacht-Master 40 on a 7.5" wrist, it would be an EE at 6 and an EF at 12 o'clock.
Best of luck getting the right fit on your Oysterflex straps.
