Mast choice Carbon or Aluminum

Build, Repair & Mod
#1

I would appreciate feedback from people who have used similar length masts that are constructed in CF or Aluminum. It appears that CF masts are vastly more expensive than their aluminum counterpart.

I’m interested in opinions on if the price/performance ratio is justified.

I’ve posted some info below on the cost associated with the current products from Slingshot where their CF product is 4X the cost of Aluminum. I’m assuming the CF products from other companies are also more $ than their Aluminum products to some degree.

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#2

For most of us the price cannot be justified. If you have too much money, live or race on the foil then maybe, but for the commoners, no way

I think that the carbon masts are extremely overpriced for what they are. I could make a carbon mast with 100% high modulus fibre in some days with 50$

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#3

@Larsb

My logic says CF is lighter and more rigid than aluminum for a given thickness of “plate”.

However once you start creating a structure that becomes less obvious at least to me.

For example is the weight of a mostly hollow extruded aluminum mast with internal structure different than a solid carbon layup??

For the efoil application I don’t think the weight difference means anything.

Stiffness of the mast on the other hand might make a big difference in how the foil works. I haven’t foiled enough to appreciate those finer differences so am curious about what they might be.

#4

Some of the structural stiffness of the CF mast comes from the foam core. You should have the motor wires inside the mast in an eFoil, so the foam core ends up damaged. For this reason, in addition to cost and percentage wise insignificant weight savings, I believe that alu masts are the right choice for eFoils.

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#5

Several mentions on the forum that the carbon masts are only equal or less stiff than the alu ones, i’d guess due to dual reasons, keep costs down for the manufacturers (less carbon cloth which is a big part of the cost) and lower weight and drag.

Carbon is stiffer than alu but there is a huge decrease in stiffness when lowering profile section so it’s hard to win that back.

I agree on the suitability of carbon masts for efoil use: If the core is removed on a carbon composite structure it will remove a lot of the stiffness as it allows the carbon to flex by buckling. If carbon layer is thick enough it won’t need the core, just like the aluminium masts that have enough thickness to avoid buckling - but that’s not how they are built.

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#6

Additionally the alu masts actually typically have an I section in the middle, which does a great job resisting buckling.

#7

Good points on the core removal. Aluminum extrusion doesn’t require that as the “wire channels” are generally built in I believe, at least they are on the Slingshot product I use.

The foam layer is the same logic as the old school fibreglass sailboat boat construction strategy of saving material costs by making the layup of the deck by using a cheap wood core sandwiched in layers of FG. All good until water gets in and rots the core. Then you have a trampoline deck to walk on. Rigidity is gone.

#8

There is a massive increase in performance if it is a well constructed mast with weight savings.
If it’s a cheap carbon mast that flexes, then it’s just terrible! In fact for a heavy rider, the lift efoil mast is actually terrible in comparison to a decent alloy mast. For me (95kg), I find my alloy mast waaaaaay better.

#9

I have to say i doubt the weight diff importance, let’s say you can shed what, 3-400 grams on the mast. Losing that much weight on your gut can be done in a week… then if it’s a massive improvement? Not so sure!

Stiffnesswise and dragwise though, sure. But the axis hm mast costs more than my whole efoil build

#10

Interesting perspective. What manufacturer of carbon mast would you consider well constructed? There seem to be a lot of companies in the game now and I haven’t been at this long enough to know which are the leading players.

#11

A problem with carbon + aluminium is the galvanic reaction created, which could lead to more corrosion on your metal parts compared to just using aluminium alone.

A insulating spacer or duralac/ tefgel and regular rinsing goes along way to minimising this though.

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#12

I didn’t know about this so went looking and came across this article. Mostly above my pay grade but counts as my learn something new each day goal!:grinning:

#13

This is axis masts comparison:

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I would guess the figures are true since the hm mast costs 1400USD :flushed:

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#14

I have carbon and aluminum Axis masts. I like the carbon mast better, since the aluminum one has a slight backlash at the junction of the mast and fuselage. The rigidity of the carbon mast is enough for me, it does not whistle. I also own an aluminum and carbon monoblock Gong mast. The monobloc mast is very lightweight, but it whistles annoyingly in all modes.

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#15

Surprising on the Axis mast connection. I think all connections should be done by grip fit:
pressed in conical adapter in the mast, meeting conical hole in fuse and a grip fit mast plate pressed onto the mast in the other end.

It’s easy, no difficult tolerances and definitely works. If i worked at a company i’d just do it, minimal cost and lots of customer hassle avoided. My Gong V1 mast was unrideable due to the slop in the mast plate.

#16

I’ll clarify. There is a backlash at the junction of the mast adapter and the mast.

#17

Interesting graphic - wonder who defined the “industry standard” value😉

Your post did prompt me to visit the Axis site and their marketing descriptions were very compelling in convincing me that carbon is better but then I recalled the $ factor!

I also wonder about the “stiffer” argument. I can see that possibly becomes a bigger factor when the span of the wing gets longer but I don’t see many build photos with those type of front wings.
As I learn more about CF stiffer is directly related to fragility, personally I wouldn’t want to be riding along and have a mast snap😳

#18

I had not thought about the sound effect factor. Good point.

I have experienced a few moments of foiling in very calm water where there is little or no background noise. I can hear the sound of the motor/prop working and the mast/foil slicing through and I can understand why an annoying sound would negatively impact that experience.

Interesting real life comparison of the two material choices. Thanks!

#19

Carbon is not going to break under normal use. Have a listen to the Generic Foiling podcast with Adrian Roper from axis. It’s a pretty good interview where he talks a lot about ast design and stiffness.

#20

My mast snapping comment was a sorry attempt at humour. I appreciate that normal use isn’t likely to cause a mast to snap unless it was badly compromised beforehand.

I can see a mast snap happening when very skilled riders start taking big jumps and the landing creates tremendous forces on the entire rig.