March 2021 – sailrepair.co.uk

Posted on March 19, 2021October 7, 2022 by John Blackwell — 2 Comments

Severne Turbo for windfoiling

Severne Turbo Sails for foiling

Introduction – The Turbo GT is Severne’s 2 cam freerace range and is a popular sail for powering fast freeride boards. It lacks the down force to pin down a dedicated slalom board but more than makes up for this by it’s easy nature. The Turbos sit between the no cam ncx which despite not having any camber inducers actually feels more slalom like than the turbo and the NCX can provide the necessary mast foot pressure to make sure a slalom board behaves itself. On the other side of the Turbo is the Overdrive which is a dedicated blasting sail. It has a wider sleeve, more battens and more cams than the turbo but most importantly it has a much more open leech. To compare the sails the size up in the Overdrive has a similar wind range to that of the Turbo for example a 7.8 Overdrive you can use in the same wind as a 7.0 Turbo.

I can’t really start with “first impressions” like I normally do with other bits of kit since I have been using Turbos for a number of years now. So I will simply describe the sails. The Turbos are a bit different compared with most other twin cam sails in that both cams are below the boom. Other sails such as the NP V8 and simmer all have a cam above and below the boom. The result is that the Turbos are probably one of the easiest rotating sails on the market, What is more is that the rotation remains constant across a wide range of downhaul settings this allows you to rig the sails with less downhaul allowing for a tighter leech but maintaining good rotation. This is one of the key factors that makes the Turbos such nice sails to foil with. Up until 2021 the sails from 6.5 downwards had only one cam and 5 battens but the new sails maintain the 6 batten 2 cam layout across all sizes. Other notable points about the sails is that the sails can be rigged on rdm or sdm masts. The 7.0 upwards are supplied with SDM cams and the small sails are supplied with rdm cams. Either type of cam can be purchased as an optional extra and they are easy to change. The cams sit on spacers so fine tuning is straight forward. The sails come with additional spacers although I have to say over the ten or so sails I have used I have not once felt the need to alter the settings of the cams despite using the sails on Maverx masts. Talking of masts the 7.0 is about the biggest sail you can rig on a 430 and likewise the 8.6 actually works better on a 460 than the 490 that is recommended. At this stage I should say that the luff dimensions are often stated. I often find myself rigging the sails with 2 to 4cm less extension than it says on the sails. I tend to look at the mast sleeve as I downhaul the sail. I downhaul until the batten above the boom is just starting to flatten at the mast sleeve. The booms are also relatively compact. While it might be tempting to reduce the outhaul to gain more power I think it is best to keep some outhaul on the sail to maintain a slightly more efficient profile.

On the water – Before you get the sails on the water you may well notice that these sails are light for their size. In use the sails respond well to pumping. There is no need to try to do big pumps, smaller higher frequency pumps tend to work better. The head of the sail should have some spring in it and you want to use that to build momentum in the sail. The result is that you should be able to get flying in a bit less wind than you would with a looser leeched sail. In flight the Turbo will provide a steady power source, feeling light in the hands. When flying through holes in the wind the sail holds its shape and maintains drive. This is where camber inducers have an edge over rotational sails by maintaining drive as the wind pressure drops. In over powered situations the sails can spill power quite easily by sheeting out just a few degrees. When gybing the sails rotate easily and normally do not require any additional pumps of the sail to get the battens to rotate and as such the turbos help maintain flight as you exit the gybe.

Conclusion – It is as if the Turbos really were designed for real world foiling. They might not fly quite as early as some of the dedicated freeride foil sails but what you get in return is a sail that will cover a wider wind range. The sails are best suited to freeride/freerace style foils boards and will suit foils with low to high aspect wings.

6.5 turbo in action – https://youtu.be/6uWdSjy1lmU

Posted on March 2, 2021 by John Blackwell — Leave a comment

Witchcraft Karma vs Slayer sails

Witchcraft Karma vs Slayer sails

This is not really a review of the sails, having a hand in designing the sails that would be a bit self serving, but with two ranges of wave sails people can often wonder which one they should buy and in this blog I will attempt to explain the differences.

Which range? Like with the Witchcraft boards you are best to look at the conditions each sail is aimed at. With a brand like Witchcraft this is easier to do this than with some of the big international brands who will design some of their products on Maui but the intended use is on a lake in Germany.

The Slayer is designed for the North Shore of Fuerteventura especially in the winter. That will mean nothing to you unless you have sailed there but it is easy to sum up the average conditions – big waves, rocky launches and moderate winds. So with that in mind, how does the Slayer meet those specific demands. Firstly The Slayer has optimized sizing which means in the small sizes the sails are designed for optimum control while the larger sizes get progressively more powerful. The 5.8 is getting quite specialised as its design brief is to get you onto the waves in the lightest winds. But once on the wave it still has to be able to go neutral at high speeds on big waves – The Slayer has the drive to keep your board secure during the bottom turn and then the short boom to help open the sail up in the top turn. The sails have large tuning ranges so that you can tune the sail to the way you want to ride. But there is no point having all the performance in the world if the sail is only going to last a couple of months so the slayers are made to take high pressure loads associated with large waves landing on them. So in summary the Slayer is optimized towards front side wave riding.

The Karma is designed more for the summer winds of the Canaries which tend to be stronger and often cross on rather than cross off. The Karma was made with spots like Pozo and El Medano in mind. In other words the Karma is designed for sailing when your main power source is the wind whether that is 10 or 50 kts. With the Karma you have an extra batten which adds a bit more structure to the sail with the aim being that the sail at one setting will cope with well powered up conditions when one minute you might be jumping and then a minute later you are riding clew first.

While this blog is about comparing the two sail ranges against each other I should say that compared to most other sail brands the Witchcraft sails are capable of getting you planing earlier. On the witchcraft website on the sail specifications it states what size sails the witchcraft sails are equivalent to. So a 5.2 slayer may well get you going at the same time as a 5.5 for other brands. Due to that optimized sizing the differences are biggest on the larger sails. Many people say “I don’t want a powerful sail for wave riding” but they are looking at it the wrong way. You can generally use a smaller Witchcraft sail than other brand sails.

Which sails to choose? Personal preference has a big influence in which range to go for, so maybe the best way to look at it is to consider the conditions you tend to sail in.

Ground swell home spot – If you are lucky enough to live on a Island stuck in the middle of the Atlantic be it Fuerteventura or Tiree and you have the opportunity to nearly always pick a cross shore break and your preference is riding over jumping then the Slayer is the logical choice but having said that the Karma is more than capable in all wave situations.

If like a lot of people you tend to sail in a wide variety of conditions from “cross off down the line” to “bump and jump” and you are happy to take any air time on offer then the choice of which range to go for is not clear cut. This situation would apply to my own sailing and I go for Karmas in the larger sizes and Slayers in the small sizes. So I have a 4.2 and 4.7 Slayer and then 5.3, 5.9 and 6.5 Karmas. I find this works well for me. I would be equally happy if my middle sail was a 5.2 Salyer. I also have a 3.7 and it is a Karma as I am looking for maximum control and range in that sail size.

If most of your sailing is blasting over chop, taking what air you can then the Karma will suit you the best as it tends to have a bit wider wind range without having to retune the sail.

The Witchcraft sails have also proved popular for wind foiling and both the Karma and Slayer ranges are equally good and indeed offer an easier flying experience than some of the dedicated foil sails!

Posted on March 1, 2021March 19, 2021 by John Blackwell — 5 Comments

JP Freefoil vs Hydrofoil boards

With JP having two ranges of dedicated wind foil boards some people may wonder which to range to go for. The 130 freefoil has a similar width and length to the 120 Hydrofoil and the 115 freefoil has the same length and width as the now discontinued hydrofoil 105. This comparison is drawn on the 105 hydrofoil vs the 115 freefoil.

First impressions- While the boards have similar widths and lengths the outlines are quite different with the hydrofoil boards having much wider tails and the volume placement further aft to match. Like for like the freefoil boards are a bit heavier due to the additional foil tracks. The deck shape on the freefoil is an average domed shape and lacks the concave around the mast foot as seen on the hydrofoil boards. The hydrofoil boards feature bevels on the underside to prevent sticking on touch down while the freefoil utilises rail shape to do the same job. The freefoil has more footstrap positions and includes the option of a single back strap. The mast track is further back on the freefoil boards.

On the water – Straight away you notice the difference in the volume distribution between the two boards. The hydrofoil has all the volume at the back of the board and on the small 105 version it is a brave person who risks putting a foot in front of the mast foot. On the freefoil the volume is much more centered and the board is easier to uphaul and a conventional uphaul stance can be used.

Getting flying – I am used to using dedicated foil boards so I naturally move back on the boards and get my front foot in the strap and then slide my back foot back as I pump. This technique works well on the hydrofoil but if I move back too early on the freefoil it tends to drag its tail a bit. This would be less of an issue for lighter riders (I am 95kg). This is where a lower aspect early lifting foil would also help. Don’t get me wrong the freefoil will fly early but not quite as early as the hydrofoil boards. Both boards are capable performers on the hydrofoil in a given wind you might use a 6.0 and a high aspect foil while in the same wind a 5.5 sail and lower aspect foil would probably be ideal.

In flight – Both boards ranges provide comfortable flights. On the freefoil you are standing closer to the rig than on the hydrofoil. You can therefore distance yourself from the rig a bit easier on the hydrofoil and therefore take more rig power, so on the freefoil you may change down sails a bit earlier. The single back strap option of the freefoil board appealed to me but in the end I preferred the double back straps.

Gybeing – While both ranges gybe well I actually preferred the hydrofoil boards for gybeing for two reasons, firstly the wider tail area gives you more working deck space to stumble about on mid gybe and secondly the additional foil tracks do add extra weight that at times I could feel pulling the board down mid gybe

Overall – There is no better or worse board here, both boards do what they claim. If you want to go fast on a foil then the hydrofoil boards have a definite edge. But for versatility the freefoil boards can take a wider range of foils and also offer the option of using a wing rather than a sail although you would need an additional foil to be able to do both sports.

Which is easier as a first foil board? If you are coming from a wave sailing background then you will feel more at home on the freefoil but if you are used to freerace or slalom boards then the hydrofoil would probably suit you best.