Bands for speargun

Bands for spearguns in natural latex and high-performance compounds, designed to deliver power, progressive loading, and shooting accuracy. Discover diameters, stretch factors, and ideal configurations for band guns and rollers.

Speargun Bands

Bands intended for spearfishing are all made from Latex, "natural latex" or "natural rubber". Natural latex is extracted from rubber latex, the milky sap obtained from the rubber tree (Hevea brasiliensis).

In this guide, we will examine the different manufacturing processes and the characteristics of the various products available on the market. We will look at stretch factors and how to calculate the cut length of rubber sold "by the meter" for rigging your speargun. We will also provide practical tips on maintenance to optimize durability and performance.

Latex compound (variability)

The latex used to produce bands for band-powered spearguns can come from different geographic sources, such as Asia, Africa, or South America, and is a natural material subject to variability depending on its origin. This variability is not only linked to the geographic region, but also extends to plants within the same area. This means latex is never a completely identical product, much like wine.

Once extracted, the latex is distributed to processing companies in different parts of the world, including America, Europe, and Asia. Each company uses customized formulas; although the term "natural latex" is common, each company develops a compound that includes various additives designed to give the latex the specific properties required for different applications, including spearfishing.

Manufacturing processes (extrusion – dipping)

There are two industrial processes for producing rubber bands intended for rigging band-powered spearguns: extrusion and dipping.

Extrusion

In the extrusion process, the compound prepared by the company, with a viscous consistency, is extruded through a die of the desired diameter and conveyed to the first drying oven. Immediately afterward it is cut into sections and then placed in vulcanization ovens, where the process ends with the consolidation of the finished product. The band produced with this process is formulated from a single compound and is therefore uniform, with a single color.

Dipping process

In the dipping process, the compound prepared by the company sits in dipping tanks, called baths, which can contain different compounds or colors as needed.

In this process, a wire support is repeatedly dipped into the tanks, with drying phases in dedicated ovens between dips. Each dip adds a layer of latex, increasing the Band diameter. Once the desired diameter is reached, the Band is cut into coils and goes through an oven vulcanization process, from which the finished product emerges.

In the production of speargun Bands, it is common for the final dips to be carried out in a compound of a different color; this way, the finished rubber will have an outer layer in a different color from the main body of the rubber.

The Band produced with this process can be made from different compounds and can therefore feature layers with different characteristics or colors.

Band compounds

The composition of the latex compound is usually a trade secret of the manufacturer. There are more reactive compounds and more progressive compounds.

Compounds defined as reactive usually have higher Shore hardness and greater elastic return, while progressive compounds are characterized by lower Shore hardness and lower elastic return.

It is important to specify, however, that the elastic return of the rubber is not always directly proportional to Shore hardness; it also depends on the intrinsic characteristics of the compound.

Reactive Bands

Higher Shore hardness of the rubber results in a higher load at the same percentage elongation, and therefore a more aggressive shot. These compounds are defined as reactive.

Progressive Bands

Lower Shore hardness of the rubber results in a lower load at the same percentage elongation, and therefore a “softer,” less powerful shot. These compounds are defined as progressive.

Today, in 90% of cases, medium compounds are preferred: high-quality compounds that combine progressive power delivery and reactivity, with excellent elastic return. When these Bands are properly matched to the mass of the shaft and speargun, they deliver the highest shaft speed while ensuring a stable, accurate shot. Very reactive compounds are avoided because they often produce harsh, less accurate shots, as are very progressive compounds, which apply less thrust to the shaft and require the use of more Bands or larger-diameter Bands, unnecessarily increasing bulk.

Band setup

Band spearguns use two possible rubber configurations. A speargun may be set up for use with “inline” bands or “circular” bands.

In some cases, a band speargun muzzle may allow the use of both types of bands, meaning it will have a seat for the inline band and a seat for the circular band. Let’s look in detail at the differences between circular and inline bands.

Inline band

The inline band consists of two pieces of band rubber of identical length, which are secured at one end to the speargun muzzle and at the other end to the wishbone.

This setup is more common on entry- to mid-level band spearguns equipped with a threaded-ring muzzle, in a single screw-in band version.

Circular Band

The circular band consists of a single piece of rubber that closes in a loop on the wishbone. This circular band is passed through a dedicated hole in the speargun muzzle.

This setup is increasingly common on band spearguns across all price ranges and in multi-band configurations, thanks to its versatility and ease of use/replacement. Circular bands are now increasingly rare in the screw-in version, while they are very common in the by-the-meter version with ties.

Screw-in Bands vs bands by the meter

There are basically two types of bands for band spearguns: Screw-in Bands and bands “by the meter.” Let’s look at the differences.

Screw-in Bands

These bands are pre-cut and fitted with threaded bushings (M16) at the ends. They are intended for use on band spearguns equipped with a threaded-ring muzzle. The band screws onto the speargun muzzle at one end and onto a threaded-ring wishbone at the other.

These bands must be purchased already sized for your speargun and are available in different diameters.

Today’s trend is to rig bands by the meter because they are more versatile and hydrodynamic, so fewer and fewer companies are investing in this product and, as a result, we have a smaller selection of rubber compounds. However, we do have one company in particular that offers a very high-quality band in the bushing version. We will look at it later.

Bands by the meter

Bands sold by the meter have undoubtedly been the most appreciated and best-selling option in recent years, thanks to the flexibility, versatility, and hydrodynamics of tied band rubber.

Bulk rubber bands, unlike screw-in bridled bands, must be tied onto the wishbone (and in some cases also at the muzzle) in order to create the band that will be mounted on the speargun muzzle. This type of band is also the most suitable for setting up roller spearguns.

The advantages of bulk rubber bands are:

Lower cost for the same length.
Wide selection of compounds and quality levels.
High hydrodynamics thanks to the smaller footprint of the tie-offs.
Stretch percentage determined by the user.
Higher performance.

The disadvantages of bulk rubber bands are:

They are not ready to use.
They must be tied by the user or the manufacturer.
If you lack the necessary manual skills, the tie-offs must be done by a specialized center, at an additional cost.

Further on, we will look at some of the best bulk rubber bands on the market.

Band diameter

The most commonly used diameters for speargun rubber bands are: 14, 15, 16, 17, 18, and 19 mm. In this case, this refers to the outside diameter.

The internal bore diameter of rubber bands can be standard (about 3.2 mm) or “small,” also known as “Small ID” (about 1.6 mm).

The outside diameter, together with the type of compound, determines the band load at a given stretch factor. At the same stretch percentage, as the diameter increases, the band load increases.

For the same length, it will therefore be more difficult to hook a 19 mm band onto the shaft fin than a 14 mm band.

Compared with a standard bore, the small bore provides a greater amount of rubber for the same outside diameter, which means higher load and performance. However, this greater amount of rubber is only a matter of a few percentage points, and is therefore more noticeable in smaller-diameter bands, between 14 and 16 mm.

Small-ID bands do have one drawback: the reduced hole size makes inserting wishbones more complex and time-consuming. They are therefore not very suitable for beginners who do not have much experience tying rubber bands.

Stretch factors and calculation

To optimize the power and accuracy of your speargun, it is important to use the correct rubber band stretch percentage. In this section we will provide only basic information; further details can be requested from our customer care team.

Bands, regardless of diameter, are generally used with stretch ratios between 300% and 400%. The higher the stretch factor and the larger the rubber diameter, the greater the load (kilograms of thrust) produced by the bands.

The ideal stretch percentage depends on many factors, such as shaft mass, the number and diameter of the bands used, their compound, speargun mass, etc. We will not cover this topic in this section because it involves too many variables, but you can always contact our customer care team for a free consultation.

Once you have chosen the rubber diameter, type, and stretch percentage you want to use, calculating the cut length of the band is very simple. There are many mathematical formulas online, but we prefer to explain the concept first.

Imagine your speargun is loaded with a circular band: measure the length of the band under tension, starting from one wishbone tie and ending at the other. The length you get corresponds to the portion of band that is actually working. Now simply divide this length by your chosen stretch factor (example: if your chosen stretch factor is 350%, then divide by 3.5). The result will be the resting length of the band, to which you only need to add a few centimeters for tying the knots (example: add 3 cm, 1.5 cm per tie). This is the length at which you should cut the rubber to make your circular band.

Band Maintenance

It is important to note that natural latex can deteriorate over time due to exposure to the elements, sunlight, and stress from use. It is therefore advisable to replace the bands whenever they show obvious signs of wear, to ensure optimal performance and safety during use.

Below are a few tips on how to care for your bands:

Regular cleaning

After each shooting session, it is important to rinse the bands with fresh water to remove any salt or dirt residue. Avoid using harsh detergents or chemicals that could damage the material.

UV protection

Bands are sensitive to UV rays and prolonged sun exposure. To prevent them from deteriorating prematurely, be sure to store your rubber in a cool, dry place, away from direct sunlight. When you are at sea, if possible, use a case or bag to protect the bands mounted on your spearguns.

Lubrication

This is a step that few people know about, but it is vital for extending the life of the bands. After every session at sea, in addition to rinsing with fresh water, use a specific silicone lubricant. You can apply this Silicon Pump product to maintain and preserve your speargun rubber. Regular application of silicone latex "replenishes" the rubber and creates a protective film that effectively extends the life of the bands.

These simple precautions will help you keep your speargun bands in excellent condition and extend their service life over time.

What are the best bands for a band-powered speargun?

The best-performing bands currently are those made from American latex with medium reactivity and progression, and featuring extremely high elastic return. In recent years, two companies have particularly stood out for the quality of their bands.

First and foremost, Rob Allen introduced Blue Rubber, a rubber recognized as the best internationally, used in multiple configurations, including spearguns intended for hunting large prey. Later, Rob Allen launched Green Rubber, optimized for the Snapper line spearguns, with characteristics similar to Blue Rubber but better suited to spearguns with maximum lengths of 120 cm.

Another company that has stood out for the quality of its bands is SigalSub. For years it has offered Reactive rubber, featuring medium reactivity and high elastic return, widely appreciated and also available with bushings. In addition, SigalSub offers Extreme rubber, distinguished by its black compound and higher reactivity than the bands mentioned above.

In conclusion

The bands are the engine of a band-powered speargun. A quality product, properly sized for your speargun and shaft, will ensure powerful and accurate shots.

If possible, test products from different manufacturers and try to understand what best suits your application. If you are unsure, rely on the models listed above: they are an excellent starting point and are considered the best by thousands of enthusiasts and industry professionals.