iSonic
Tuning Tips by Tiesda You

Footstrap tuning

The position of the back straps is the first item to tune - an iSonic board will typically have either two or three hole inserts to allow the strap to be adjusted forward or backward. If three holes are present, the middle hole is the one we recommend - this is the position we've been using when we test the boards and it's the position the majority of our team riders use. If you select the hole in front, the board would give you more control and planing is easier. If you select the hole behind the centre hole, you will get more power from the fin but control will be more difficult. In many iSonic models, we have chosen to only have two holes to help save weight - in this case the back hole tends to be the option we use and therefore the one we would recommend. The front one would be used if you need more control and easier planing.

Each strap is fixed via one screw at either end of the strap. If you are going to use the middle hole for example, always make sure you use the middle hole for both ends of the strap - it'll give you a strap width of 15.5cm - a common width that works for many people. Of course, if you have very small feet, very large feet or wear boots while sailing, you can select a different hole that would increase or decrease the strap width by 2.5cm.

Remember to place the K9 insert in between the board and strap - it will greatly reduce the chances of the strap twisting - of course, also ensure that you fix the strap with as much screw tension as your arms can apply. Many people under estimate how much screw tension is needed, which means that the strap will sit loose, twist and over time, also undo itself. In the worst case, a screw can shear out and leave you with a damaged hole.

Some iSonics will also have an inboard or an outboard setting for the back strap. If you have large feet or if your riding style is more 'on-top' of the board, go for the inboard setting. If you like to curl your feet around the rail and ride 'off-the-rail', go for the outboard setting. Note that the spacing between the inboard and outboard setting is 2.5cm. This allows a strap to be fixed in between these two options by using two screws at either ends of the strap. This of course also makes the strap position more secure - it will be impossible for the strap to twist since two screws are fixing it at both ends.

So now your back strap is set.

For the front strap, we also recommend the middle hole. If there are only two holes, we would recommend the hole that matches the one you selected for the back foot, whether it's the front or back hole. If you are particularly tall or short, or if your riding style requires a shorter or longer stance, then you can select a different hole that would increase or decrease your stance in 2.5cm increments.

Some of the iSonic boards also have an inboard or outboard setting for the front strap. The right setting for you follows the same guideline as for the back strap. And just like the back strap, the double row of inserts also allow you to choose a position that is in between. With two screws fixing both ends of the strap, the strap will be very secure and simple cannot twist.

What is also interesting about the double-row front strap inserts on some of our iSonic boards is that this configuration also allows the front strap's angle to be changed: you can adjust the front strap to be more parallel to the rail, or more perpendicular.

So your straps are set, now it's time to fit the fin.

Fin tuning

Because our iSonic are fitted with the Tuttle fin box system, you don't have to worry about the position of your fin - it's fixed. However, do consider carefully what size fin you will fit. It's importance is often underestimated, and by a lot. See it this way: in different wind conditions, we tend to change sail size. Well in different wind conditions, you should also be changing fin size. Yes, it's that critical, and the wider the board, the more critical.

If we take our iSonic 122 for example, we supply you the board with two fins straight from the box - just to make sure that you get to enjoy the board's vast wind range. As a basic guideline, we tend to use the larger fin when matching the board to sails above 8.5m2, and the smaller fin when matching the board to sails below 7.5m2.


In our largest and smallest iSonics, we only supply one fin because most users tend to have these slalom boards exclusively for lightwinds or highwinds. But if you want to extend its wind range, consider a second fin before you consider a second board!

Mast-track tuning

For mast track positioning, we simply recommend the middle position. This middle position is clearly marked on the board and just to make it as clear as we could, we even printed recommended position' next to that mark. When we test the board and when our riders use the boards in competitions, we all tend to place the mast track on that mark. Our board design evolution has lead to that exact position and not surprisingly, that is why it's the centre of the track.

Some adjustment is of course possible. This will allow the board to adapt to your personal preference or the prevailing conditions on any given day. If you need a bit more control in overpowered conditions, moving the mast track forward a little will help. If you want more power on the fin, moving the mast track backwards a little will help.