I switched from carbon to aluminum about 10 years ago after breaking a carbon extension (Streamlined).
The advantage of aluminum is I can still sail back to the beach after bending them. But I have yet to find a brand that lasts longer than 12 months before I bend it. So far I've bent 2xSimmer, Gaastra, 2xNeil Pryde, 2xAeron, Goya and one other that I can't remember the brand of (I bought it in Europe pre covid). What's more resistant to bending than those brands
Streamlined carbon is what i use. Yes, I have broken one -but that is still better than the pile of aluminum ones I have bent.
Select to expand quotejdfoils said..
Streamlined carbon is what i use. Yes, I have broken one -but that is still better than the pile of aluminum ones I have bent.
Thanks. Does anyone in the USA still sell them? I see they are based in Europe now. Are Streamlined carbon extensions stronger than say Goya carbon?
My Chinook Ali has endured many seasons of punishment and is still straight as a die. Also their euro pin base plate is equally tough. I believe it is the only one on the market with the pin moulded onto the the top piece, so there is no risk of the pin breaking. I think they are still made in the US too.
Sailworks had streamlined but i think they are closed now.
I think Kevin at sunset sailboards sells them in the bay area.
I've bent many chinook extensions...
Severne grenade. Much thicker ally than all of those IMO
dunno what you guys are doing to bend quality extensions though, as a fat guy wavesailing using a 120L board and bigger sails than everyone else and crashing lots in 30kn I replaced my Severne ally one only as the fittings were wearing out from use after many seasons. Tube is fine.
I won't use carbon since snapping one and it's impossible to dodge it up to self rescue .. And splinters everywhere 4" from your foot trying to bog back in to the beach . but I think if the holes are moulded in rather than drilled it would be worth it.
Select to expand quoteMark _australia said..
Severne grenade. Much thicker ally than all of those IMO
dunno what you guys are doing to bend quality extensions though, as a fat guy wavesailing using a 120L board and bigger sails than everyone else and crashing lots in 30kn I replaced my Severne ally one only as the fittings were wearing out from use after many seasons. Tube is fine.
I won't use carbon since snapping one and it's impossible to dodge it up to self rescue .. And splinters everywhere 4" from your foot trying to bog back in to the beach . but I think if the holes are moulded in rather than drilled it would be worth it.
Would it be fair to assume that the more extension that you are using (ie max setting), the more likely it is to bend?
I don't think being fat would affect it, unless you sat on it 
Oh indeed more extension is worse
but I'm thinking when u crash the load a wave puts on a 120L board and 6m sail, vs the less manly sized folk wavesailing on 70L and 5m in the same conditions
i preferred my 5.7 set on a 400 mast with 34cm ext instead of the recommended 430 +4 and still Severne prevailed.
Be aware that Alu sometimes just snaps clean, without bending/deformation (Chinook as above) in not too crazy situations.
I prefer carbon altogether.
Select to expand quoteMark _australia said..
Oh indeed more extension is worse
but I'm thinking when u crash the load a wave puts on a 120L board and 6m sail, vs the less manly sized folk wavesailing on 70L and 5m in the same conditions
i preferred my 5.7 set on a 400 mast with 34cm ext instead of the recommended 430 +4 and still Severne prevailed.
Are you suggesting that the likes of Jaeger Stone and Thomas Traversa on their 70L equipment are 'less manly' and also placing less stress on their mast extensions, than yourself?
Select to expand quoteDoggerland said..
Be aware that Alu sometimes just snaps clean, without bending/deformation (Chinook as above) in not too crazy situations.
I prefer carbon altogether.
I have never heard of or seen this before.
Any photos?
Happened twice on low range (15-20cm)
Same motivation for switching to Ti bicycle frames...sometimes alu does give you warning/saves you by bending...but usually just a clean -fatigue- break despite the myth.
Select to expand quoteMuppet said..Mark _australia said..
Oh indeed more extension is worse
but I'm thinking when u crash the load a wave puts on a 120L board and 6m sail, vs the less manly sized folk wavesailing on 70L and 5m in the same conditions
i preferred my 5.7 set on a 400 mast with 34cm ext instead of the recommended 430 +4 and still Severne prevailed.
Are you suggesting that the likes of Jaeger Stone and Thomas Traversa on their 70L equipment are 'less manly' and also placing less stress on their mast extensions, than yourself?
You know what I meant. 
I'm comparing mere mortal crashes not theirs. Plus they don't care quite so much about breakages and have quite a supply of new gear huh
Select to expand quoteMuppet said..
My Chinook Ali has endured many seasons of punishment and is still straight as a die. Also their euro pin base plate is equally tough. I believe it is the only one on the market with the pin moulded onto the the top piece, so there is no risk of the pin breaking. I think they are still made in the US too.
Bent several of these.
Not a big fan of sails that call for lots of extension say a 4.7 that needs 30cm to rig on a 370 flat water no problem,waves probably going to bend or break.
^^ thus why I love SV
years and years of 26-34cm ext on my most used sails. Crashed lots. Broke everything I can think of except the ext. Got a new one as the cleat was wearing but the tube is still good. Its thick, and has no gimmicky superfluous crap.
Select to expand quoteMark _australia said..
^^ thus why I love SV
years and years of 26-34cm ext on my most used sails.
Snapped a Severne 36cm carbon wave extended at 26cm up in Gnaraloo getting munched by a mast high roller while standing in the impact zone. Nothing else broken. I guess extension was cheaper than a sail, mast or board. Severne sold me a replacement extension at cost so not complaining... now using the broken one as a 0-10cm extension.
Bent 4 Neil Pryde alu extensions and snapped two Chinook alu back in the day. Seen Chinook carbon, North Carbon, Goya carbon extension break. I think especially if you get roller in a shortbread or shallow reef / sandbar break something will eventually break.
Had a carbon chinook RDM snap on me last week after 16 years of sailing and abuse. I think that's a pretty good innings!
Ditched gear after slogging out and incoming set. chinook euro base still strong as the day I bought it though yeuw
When do you guys decide to ditch your gear? A few times when really big (3m+) I decided to sink and ditch. It worked but I'm not sure it's the best idea. It's when I'm just under a curly one right in the impact zone. Any other case I sink and hang on.
Only used Chinook alloy rdm extensions, taking care not to go so long. I prefer to use a small mast tip extension or one mast half longer instead.
Usually ducking the sail is easy on the extension. The main issue has to be shallow and heavy shore break, not much we can do there besides timing and luck!
Can see some sinking there:
Ditch the gear if you are too late to duck the sail under the wave, and definitely ditch it if it feels too dangerous to hold on.
I decided to try a carbon extension. Since I typically get about 1 year out of an aluminum extension before I have to replace it, as long as the carbon extension lasts more than 1 year and 8 months then I have saved money.
We had this problem for years up to about 14 years ago. Getting fed up with boxes full of bent and broken extensions I had an intern examine if we could not solve this. Examining bent extensions we quickly found the solution: Extensions always bend sideways, where the holes are and they are the weak point. With alu extensions there is always one holes squashed and the other stretched. I presume because they thought the biggest force on an extension is the downhaul. But in use the sideways load of a wave in the sail is much bigger then any down haul. He calculated that just turning the holes 90 degrees made the extension 96% stronger for the side ways load. This is with 6mm holes, with 8 or 9mm holes, the differences will be a lot more. So I turned the tubes on some extensions and for a year none broke so I started looking to get more without having to modify them afterwards. I wasn?t looking to produce extensions myself so I informed the suppliers I had at the time, from which we had loads break, without guarantee. None of them even responded. So I asked my mast manufacturer MaverX Claudio from Reglass, who had been staying with us as we had been helping them to develop their masts. He said they produce the ferrule as longer pieces which are then cut down and he could make them any size and also beef up the diameter to have a tighter fit then with most extensions. I made a set up for my CNC machine to drill the holes and I got the pulley parts and rings from Chinook. A few years later I changed to a chinese supplier which tube runs all the way to the bottom. Still havent had any broken since but one that got driven over by a car on a stony surface. Since a few years also Chinook turned the holes 90 degrees. There is no mention anywhere of this on their website but you can see in the picture. So these should now be a good option as well.
Select to expand quoteBouke-Witchcraft said..
We had this problem for years up to about 14 years ago. Getting fed up with boxes full of bent and broken extensions I had an intern examine if we could not solve this. Examining bent extensions we quickly found the solution: Extensions always bend sideways, where the holes are and they are the weak point. With alu extensions there is always one holes squashed and the other stretched. I presume because they thought the biggest force on an extension is the downhaul. But in use the sideways load of a wave in the sail is much bigger then any down haul. He calculated that just turning the holes 90 degrees made the extension 96% stronger for the side ways load.
you don't need any finite element simulation to know that the holes seriously reduce the thrength of the construction.
But it is good to see in clear daylight.
I am so fed up with the some of the big windsurfing manufacturers.
They produce low quality gear but charge premium prices.
What really pisses me of is 1.) that some of the problems could easily be fixed by them.
2.) that this get you you in life threatening situations. Just because some plastic part of a boom or extension breaks because of some cheapish screw corrodes and cracks the plastic. (e.g. Happend to me with all the duotone parts. The plastic is to brittle)
3) They are so ignorant to react to these problems.
Select to expand quotestehsegler said..
Snapped a Severne 36cm carbon wave extended at 26cm up in Gnaraloo getting munched by a mast high roller while standing in the impact zone. Nothing else broken. I guess extension was cheaper than a sail, mast or board. Severne sold me a replacement extension at cost so not complaining... now using the broken one as a 0-10cm extension.
Bent 4 Neil Pryde alu extensions and snapped two Chinook alu back in the day. Seen Chinook carbon, North Carbon, Goya carbon extension break. I think especially if you get roller in a shortbread or shallow reef / sandbar break something will eventually break.
Imagine the energy of these impacts. I am always astonished to see that most of the times the gear survives. It cleary makes sense to a a weak spot which breaks so that rest stays intact. Who prefers to buy a mast instead of an extension.
Select to expand quoteSchobiHH said..
some cheapish screw corrodes and cracks the plastic.
indeed the hidden flaw in many diabolo types. Corrosion = minute but very powerful expansion, destroying the plastic assembly.
Preventable.
Select to expand quoteSchobiHH said..stehsegler said..
Snapped a Severne 36cm carbon wave extended at 26cm up in Gnaraloo getting munched by a mast high roller while standing in the impact zone. Nothing else broken. I guess extension was cheaper than a sail, mast or board. Severne sold me a replacement extension at cost so not complaining... now using the broken one as a 0-10cm extension.
Bent 4 Neil Pryde alu extensions and snapped two Chinook alu back in the day. Seen Chinook carbon, North Carbon, Goya carbon extension break. I think especially if you get roller in a shortbread or shallow reef / sandbar break something will eventually break.
Imagine the energy of these impacts. I am always astonished to see that most of the times the gear survives. It cleary makes sense to a a weak spot which breaks so that rest stays intact. Who prefers to buy a mast instead of an extension.
We still do not see an increase in breaking masts. Probably because it matters where the wave hits. If it hits close to the extension, the extension was the weak spot. If it hits the middle, the mast is the weak spot and also regular extensions hold up. But we do have a big reduction in colateral damage from breaking extensions.This survived all fine:
