The forces applied by large front wings make any 13.5mm aluminium mast unsuitable.
Smaller kite wings, as these masts were originally designed for. Ok I guess.
But they are way too flexible / wobbly. We all adjust and try to make the most out of what we have.
But when you ride a stiff mast, nothing else really compares and the difference is dramatic.
2 Likes
Would you say that the 16mm would be a decent choice for an efoil or the 19mm is the only way to go despite the added drag/weight?
Stiffness of mast and connection points is critical imo so I’d go with 19mm any day. Weight difference is less than 8% between the 2 masts, so I am not that worried.
Stiffness difference between the 16mm and the 19mm is more noticeable on larger wings, and when carving and turning hard. For straight lining, either would be manageable I’d think.
The extra space though of the 19mm mast is nice to work with though.
There are a number of things that play a role with perceived stiffness:
- mast base connection
- mast fuselage connection
- fuselage twist
- fuselage wing connections
- lastly the actual mast
Once you are 100% sure the first 4 have zero impact you can start looking at the mast itself. I have ridden wings up to 1600 with the going mast and felt no flex.
For a speed record, go for the thinner mast. It’s going to have less drag.
You can also try the thinner mast on bigger wings and see if you notice any flex.
I have an axis setup I bought for wakefoiling. The only reason I went with it was my brother is 6’7" and 115kg so I figured if anyone needs a strong mast it’s gonna be him. The axis construction and finishing is stunning and worth every cent. I honestly can’t remember if it was the 16mm or 19mm one though.
I have a new motor coming soon, so I need to decide on a mast and may very well get the 16mm axis just for something different. Just wish they made it in black.
I tested my mast yesterday, very easy to spot a contributor to flex when looking for it. The upper mast mount allows play in side-side direction. I’ll glue it solid.
…but still very easy to flex mast sideways when the play in mount has bottomed out.
No noticeable play in bottom connection
Best way to check mast flex is to use it like a bridge and slowly weight it until you see some flex. That way you know how much force it can handle before the flex starts.
It’s very low forces, some kilos at the most for the assembly. mast alone naturally less flexible. Using it as a bridge is not relevant load case, should be fixed one side, free the other to load as on the board. unfortunately my cables and connectors stop disassembly, otherwise i’d try it tonight.
Then clamp one end of the mast horizontally and start loading the other end with weight.
“I have a new motor coming soon, so I need to decide on a mast and may very well get the 16mm axis just for something different. Just wish they made it in black.”
It took AXIS 17 different anodization factories to find the perfect red for their masts
I’d say go with it - it will look stunning under your board 
Thats a good idea to see how much flex it has. To be honest, I wouldn’t be surprised if it shows some flex just from the weight of the motor.
Hi guys.
I’m a bit confused about all this mast flex concern. Can someone explain the problem here? Are we talking about trying to minimize flex because we are concerned about failure, or is it because the flex is an undesirable feeling?
As long as it’s tight and there is no wobble (I hate a loose / wobbling feeling) the flex doesn’t matter. It is consistent, and predictable. It’s just a matter of learning the feel of the total setup, flex included, and then you can just forget about it. How many hours of ride time have you put in on the mast with flex that you’re unhappy about? I don’t see the problem.
Look at the wings on a wide body aircraft. They all flex. The flex is part of the strength. Things that flex can absorb shock, build up load smoothly.
I like my mast flex. It’s a very smooth, fluid, carving feeling. Idk. Never bothers me. Maybe I’m crazy… actually, I’m pretty sure I’m crazy. 
I get a snaking feeling when riding, just like a 30 000 km old car with dead steering. It comes mainly from the slop in the upper mount i’m sure.
Not sure though if you’re a lean surfer type that you’d notice the same as me.
Difference in weight might be similar to the difference in stiffness between 13 and 16mm wide mast without knowing your size (or like if a thin guy would ride a 10mm mast)
My riding weight is 132kg, board included.
I’m looking for an Mast Clamp STL for my Liquid Force Foil. It looks like the same profile as yours (thinner than most) 131mm by 13.5mm. Do you have an STL file for an LF Mast Clamp to fit a Flipsky 65161 Motor that you could share ?
1 Like
Did you ever get a reply to this?