Best rubber for a watch strap
The number of rubber watch straps on the market today is quite extraordinary. Rubber watch straps originated in the 1960s, but they’ve since become far more popular than those early originals. As we’ll discuss below, the combination of lightweight, replaceability, and practicality adds tremendously to their appeal.
Of course, not all rubbers are the same. While old rubber straps used natural rubber, later iterations used different chemical formulations to achieve specific ends. Here are some of the most common rubber-strap materials you’re likely to encounter and their advantages and disadvantages.
Natural Rubber Watch Straps
Natural rubber straps first emerged in the 1960s for use on diving watches. Up until that point, divers had been using bracelet straps. While they did the job, they could sometimes break and were expensive to replace. Divers needed something reliable that would hold their timepieces on their wrists and prevent them from sinking into the briny depths.
Tropic introduced the rubber wrist strap in the 1960s, and soon after, both Tudor and Rolex began using it on their sport models. Since then, natural rubber has been a popular choice for people looking for extra durability.
Natural rubber (sometimes called latex), has several advantages. The first is that it's incredibly affordable. Countries like Indonesia and India grow vast amounts of the stuff and export it all over the world in bulk, bringing the price down. The second is that it has a natural stretchiness that’s intrinsic to the material itself. You can pull, compress and warp it in a variety of directions, and it’ll just bounce back to its original position, unlike bracelet or leather straps.
There are, however, negatives, even if you plan on using it in diving or sporting situations. The first is that natural rubber doesn’t provide any natural sweat-wicking, meaning that things can get a little clammy if you’re using it in the heat. The second is that rubber watch straps aren’t particularly resistant to heat and light. While a regular bracelet watch strap will sit out in the sun all day with no degradation, UV light can cause the polymers in natural rubber to break down. Over time, the quality of the rubber falls.
Silicone Watch Straps
Unlike natural rubber, silicone is a synthetic product. Manufacturers developed it to overcome some of the limitations of traditional rubber and give consumers a more durable product.
Like rubber, silicone is both lightweight and resistant to water. It’s also able to elongate, compress, and withstand the general wear and tear of being worn on the wrist. The downside is that it is not particularly good at resisting oils, which is why you never see it in hydraulic systems. While you might not think this a problem for watch straps, it is an issue if you’re in an oily environment or your skin produces a lot of natural oils.
Furthermore, just like rubber, silicone probably isn’t the best material for dressy watches. While it’s great for outdoor pursuits, it can let you down on the aesthetic front.
FKM Watch Straps
FKM fluoro rubber is a type of fluoroelastomer that you sometimes find on watch straps. Just like silicone, it’s a mostly synthetic product designed to improve on the characteristics of natural rubber.
It differs from silicone in several ways. The first is that FKM isn’t as stretchy as silicone. Chemical industrial companies that work with the material describe its elongation as “poor.” You also can’t compress it as much as silicone without damaging it. Thus, from a physical perspective, it’s a far less resilient material than silicone.
It does, however, have some advantages that silicone doesn’t. First, it’s robust to practically any kind of oil, including synthetic and fuel oils. It’s also surprisingly resistant to alkaline and acid solutions too. Thus, what you lose in terms of physical durability, you gain in terms of chemical durability.
PU Rubber Watch Straps
Polyurethane rubber is a type of rubber mixed with plastic to give it the softness of the former and the rigidity of the latter. The elastomer itself is exceptionally durable and functional, although some people might find it too hard and rough on the skin. Typically, you find PU rubber straps on diving watches, often in a bright color, though not necessarily.
EPDM (Ethylene-Propylene Diene Monomer) Watch Straps
EPDM or ethylene-propylene-diene monomer is a bit of an all-rounder in the world of rubber watch straps. You often find the material used on pads and rings for industrial applications. It is both weather and ozone resistant and has high chemical stability, so it shouldn’t react with anything that you might encounter in the environment. While it’s not as tough as silicone, it is still surprisingly strong and durable, again making it ideal for outdoor applications.
Why You Might Want A Rubber-Style Watch Strap
Bracelet-style and leather straps are currently trendy among consumers and for obvious reasons: they help to show off watches at their best. Rubber, however, has its roles too. Check out these reasons why you might want a rubber watch strap.
You Want Something That Doesn’t Conduct Electricity
Most people don’t spend all day wiring sockets and rooting through fuse boxes, so the electrical conductivity of a watch strap doesn’t matter that much. If you’re an electrician, however, it suddenly becomes very important indeed. Electricians need straps that protect them from current passing through wires. Fortunately, all kinds of rubber are natural insulators, stopping hazardous jolts in their tracks
You Need It To Be Waterproof
Unless you have a costly gold or platinum bracelet, bracelet wrists straps aren’t entirely waterproof. Over time, there’s a risk of corrosion, especially if you’re wearing them in the open ocean. Rubber wrist straps, however, never corrode.
You Want UV Resistance For Outdoor Use
While natural rubber isn’t the best at resisting UV light from the sun, other rubber-style straps, like silicone, are much better at it.
You Need It To Be Non-Allergenic
Some people can have adverse reactions to metal bracelet straps, but very few, if any, have a rubber allergy.
You Want Something That Is Easy To Clean
Scrubbing all of the links in a bracelet or cleaning leather isn’t easy. With rubber, however, it’s far easy to remove all the gunk and grime.
You Want Something That You Can Replace Cheaply
If you wear your watch while exploring, traveling the world, or adventuring, there’s a good chance that you’ll damage the strap. Rubber, however, makes for cheap replacements.
The History Of Rubber Watch Straps
Rubber watch straps made their first appearance in the 1960s and were marketed to divers. Rubber was not only water-resistant but also robust, making it an obvious choice for those venturing below the waves.
Not all manufacturers, however, made straps that consumers liked. Many people complained that they weren’t durable and that they were uncomfortable. Others just didn’t like the look.
The utility of rubber straps, however, wouldn’t go away, and companies like Tropic ultimately created products without the downsides of their competitors. Before long, both Rolex and Tudor began including the Tropic rubber straps on their diving watch ranges.
Soon after that, a whole host of companies tried to develop rubber straps of their own. Dive and sports manufacturers, in particular, were keen on the idea and saw how it could help their customers deal with the problems that they often had with their metal and leather straps.
Rubber straps have features on several well-known watch models throughout history. Blancpain, for instance, introduced its Fifty Fathoms watches in 1953. Over a decade later, the company began using Tropic’s straps on the dive watch.
Tropic straps also found their way onto the Super Compressors of Ervin Piquerex S.A. (EPSA) - a particular kind of watch designed with a patent case-sealing method.
IWC’s Aquatimer - a watch that used EPSA cases - used the Tropic strap when it came to the market at the end of 1966.
The Difference Between Fitted And Generic Rubber Straps
The majority of rubber style watch straps are generic - straps designed to fit almost any watch. By making them at the most common sizes (usually 18, 20 and 22mm lug width) and giving them a straight end, they can fit any watch of the appropriate dimensions.
Some brands, however, make special straps designed to fit their watches perfectly. These tend to have curved ends and solid nylon pieces designed to keep the strap flush against the case, even when under pressure.
Fitted straps are less common as they are more expensive - a new mould needs to be opened for each model to ensure the perfect fit, and moulding is an expensive process. As a result though, fitted rubber straps tend to look better than their generic counterparts.
How Much Do Rubber Watch Straps Cost?
This is one of those "how long is a piece of string?" questions. There are a lot of factors at play when it comes to pricing anything, and materials are just one of them. So while it may cost anything from $2-$50 to make an individual strap, things such as complexity of design can have a big effect on the final price. So while you can pick up a basic one for just a few dollars on Amazon, Rolex charge around $400 for theirs. It's a great strap with some complex design and cooling features, but that's still a lot of money!