HULL SUPPORT

“Should I use rollers on my trailer or is a combination of bunks and slides better?”

The question above is one of the most frequent issues we try to address for clients seeking to replace or upgrade their boat trailer. Most have used roller trailers in the past and most have also seen the more recent emergence of trailers fitted with bunks and slides, or a combination of these with rollers. Understandably, many are curious.

The best solution considers how the boat will be used, and the choice of rollers or slides is then defined to provide the best performance. At Spitfire SA Boat Trailers, we strive to provide ‘happy boating’ outcomes where performance is the key driver of satisfaction.

Trailers we are replacing today were fitted with ‘best practice’ options 15-20 years ago. And while trailers have undergone change, the needs of the owners have changed in that time, too. Older clients are finding their boating to be more physically demanding and their trailers too easily cause frustration and become high maintenance or costly. More often, many of them are using the boat on their own. Younger clients now have families who want to be more adventurous, towing and exploring more widely. A new trailer for an older boat must therefore cover the changes in performance expectations too.

Bunks/slides and rollers are two distinct options for keel and hull support and have their respective advantages and disadvantages. Trailers are somewhat defined by the keel and hull support. Flat, concave, or VEE rollers under the keel and wobbly rollers under the hull define a ‘roller’ trailer, while keel slides using nylon, Teflon, or HDPE coupled with the same, plus carpet, under the hull define a bunk/slide trailer.

In the past 15-20 years slide materials have changed more than rollers. This has allowed favourable alliances of wear materials and alloy or fibreglass hull surfaces. The design of some trailers too, focuses on more convenience, longevity, and enjoyment – and less maintenance.

Rollers have not changed much over the years and still combine galvanised shafts and sliding surfaces that rust and seize. Sliding materials, however, have improved considerably. The best available, such as HDPE or equivalent, provide fantastic sliding and hull-friendly properties. Together with lower trailer profiles, bunks and slides now offer excellent reasons to simplify trailers and reduce unnecessary costs and maintenance. Why complicate your boating experience? Bunks and slides in materials such as HDPE have emerged as big winners for fibreglass boats, having been the domain of alloy boats in the past.

There are fundamental differences between rollers and bunk/slides on trailer performance. Provided they are working, rollers adapt easily to the contours of hulls and offer smooth loading and unloading experiences, particularly in shallow water, and off beaches. However, without considerable extra hardware around them to stop inadvertent damage to keels and hulls, they can often cause costly damage in windy or challenging retrieval situations. Rollers are also a point of load against a hull surface, which can cause longer term cracking or denting when too few rollers are deployed. Rollers are also beneficial for boats with pronounced keels or unique hull designs.

Bunk/slide combinations, on the other hand, distribute the boat’s weight evenly across a wider area, providing a much more even and hull or keel-friendly support. When using HDPE, the friction coefficient is lower and more friendly to a hull surface than other materials. During challenging retrieval, side bunks can usefully deflect boats back towards the centre of the trailer. Maintenance of a modern slide is negligible, and they are a cost effective, simple, and durable solution. Carpets should not be used due to filtering and trapping sand and grit, and risking osmosis when in wet contact with fibreglass hulls.

Any trailer configuration that increases the surface area of contact against the boat hull is much better for your boat because it spreads the load. This is easier to achieve with bunk and keel slides than rollers.

At Spitfire Trailers we believe that best performance and boating enjoyment through your trailer is assured by keeping the trailer configuration simple, relevant, low maintenance, and hull friendly. Our recommendations 99 per cent of the time are to use bunk and slide combinations with just a few select rollers to contour with the forward hull. Happy Boating!

Spitfire SA Boat Trailers, Adelaide