Limba VS. Ayous in the second layer

I had this conversation so many times that I decided to write a post about it. If you look at the composition of a Butterfly blade online you will see Limba written all over the place for their second layers. That is incorrect. The truth is that Butterfly doesn’t disclose the composition of their blades, all you see online are just guesses that got passed around, and unfortunately the majority of them are incorrect. Butterfly uses Ayous in the second layer for the majority of their blades, such as Viscaria, TB line, ZJK line, Innerforce, etc…

How do I know this? The difference is clear if you know what to look for, but I also saw the inside of some of these blades and proved it myself. There are brands that use Limba, such as Xiom for example, and if you compare a Viscaria with a 36.5 you will see what I mean.

Ayous can look like Limba in certain situations, but Limba is unmistakably Limba. First you gotta look at the end grain, which for the second layer will be on the side of the handle. If you look at the bottom of the handle they will look the same. Also, the blade must be new or in good condition, when sweat gets into the handle it makes the grain swell and the wood darker, which hides the characteristics we are looking for.

Limba is usually darker than Ayous, that’s a clue, but it may not be the case. The give away are the little diagonal lines you can see on the Ayous layer, which Limba doesn’t have. They are called medullary rays, cellular structures found in some species of wood, what we in the TT world also call the fish scale pattern.

So, is there a big difference? Not really… If we look at the average density of each wood, Limba is about 1.4x heavier than Ayous. For a normal blade this means 3-4g more. Limba is also about 1.5x harder than Ayous, this will give the blade a slightly harder touch. In the end, all else being equal, a blade with Limba instead of Ayous will feel a little harder, less bouncy, but with more speed potential.

The middle ply adds very little stiffness to the blade because the wood grain is at 90º, so it contributes more to the perceived hardness than the speed. So we can control the type of feedback by choosing a softer/harder or thinner/thicker layer. We can also introduce a composite layer, which is an isotropic material, so it will have important mechanical properties along all directions.