Most extensions are designed with the idea that the downhaul tension is the biggest force. Thus the holes are placed sideways. However, in wave sailing, the far bigger force on the extension is from a wave crashing in the sail. This load is sideways. Strength analyses show that by turning the holes 90°, the highest force in the tube (where it will break) is reduced by 46% (1494 MPa against 797 MPa). So turning the holes 90° alone makes it 87% stronger, without increasing weight. See pictures of the analyses using finite elements below. These analyses were done with 6,5mm holes, comparing this with extensions with bigger holes, the difference is even bigger.
On top of that, we increased the outside diameter to 32.5mm over the standard 31.5 to 32mm to reduce play inside the mast creating point loads. By increasing the diameter. we also increased the wall thickness and the carbon content to 90%. All this is creates an unbreakable extension that still only weighs 492gr.
All the important parts are made from stainless steel which show practically no wear for over 10 years now.

Probably the strongest extension ever.
Not one breakage since 2013 and counting.

Weight: 492 gr

249 €

2 years guarantee

The extensions have an outside diameter of 32.5 +/-0.1mm to fit in the standard internal diameter for RDM masts of 32.8 to 33.2mm. If in doubt about your mast, please check your masts diameter before ordering that it has at least 32.8mm inner diameter and it has the same diameter over at least 45cm from the bottom. A mast should have the same diameter over this length as, if it is tapered, the extension would get more play in the mast, the more you extend it, which is what you definately do not want. Clean the inside of your mast well before not to scratch the extension so if it does not fit you can return it and get a full refund. Mast brands that we know to fit: Ezzy, Goya (if made by No Limitz), No Limitz, MaverX, Reptile (not the reverse), Simmer. Please inform us if you know other brands that fit or do not fit.