Anyone regularly use their reduced diameter carbon boom at maximum extension? Bad idea or not?

I did until I snapped by boom extension. Bad idea for duck gybes.

I'd say using any boom on max extension is a bad idea - carbon or otherwise.

Every boom gets more flexible when set at full length and then they just feel so soft when you pump the sail. That excessive give then affects outhaul tension.

With aluminium, pumping and excessive flex will slowly work-harden the aluminium until it eventually breaks. The equivalent carbon booms shouldn't actually break, but what you feel in your hands should tell you if it seems strong or not.

Wave booms tend to work up to 5.2m rigs for me, but then feel too soft for a 5.5 or 5.7 - so it's best to have a longer boom for those bigger size sails.

I heard years ago to only extend them 1/3, but I have taken a standard diameter 160-220 carbon boom out to 200 regularly with no problems

I suppose the question is, "Why do manufacturers print on a boom that it is 170-220, if it won't work at 220?" Surely they believe it is structurally suitable for the stated maximum length if they state it is?
(That said, I always use 10cm less as the maximum I would extend to. )

I use my Duotone Carbon EPX 175 - 225 regularly at 219 extension on my Warp 7.7 without any discernable reduction in stiffness.

YOU SAY RDM .boom .I always thought RDM mast where stronger ,
any way ,i have a naish carbon boom and use my 180-240 at 237 quite a lot .

it does feel a little more flexy at the end ,but still has a fair bit of length in the guts of the boom ,so i'm with mickey 100 ,they must have tested it ,and would say it should not be a issue ,unless jumping a a lot .

I have often thought of getting a 220 -260 ,love the stiffness the carbon booms give .

you could always find a carbon insert ,and glass that in the ends ,then re-drill a few holes

I loved my 170 to 220 carbon boom. One boom for nearly all my sails. That was until one day with normal use on 210 extension it simply snapped behind my back hand. Warranty claim but I will probably use a bigger boom for the larger sail from here on.

Select to expand quote

Tardy said..
YOU SAY RDM .boom .I always thought RDM mast where stronger ,

That's because SDM carbon masts have to have thin walls so they aren't too stiff, so they crush easily. Not so with booms, you want them as stiff as possible.

Everything has it's limits, it's going to fail sometime. Using a boom at full extension will just make that fail time shorter. By how much, depends on too many variables, to even have a remote idea.

I extended an extra tailpiece on my wave boom as it was long enough for a 6.4 but was a bit scary.
Just got a spare tail, made it 10cm longer (so it won't go to minimum now). But, stiff as hell at "full" extension. Still on 190cm, but stiffer.
And alI have to do is carry that extra tail and only if the forecast is crap so I'm taking that one large sail

So why don't they make an extra tail at a reasonable price to include with new boom? Like an extra $200 or so for a long tail?

Is the flex in the tailpiece or the boom arms?

Select to expand quote

Mark _australia said..
I extended an extra tailpiece on my wave boom as it was long enough for a 6.4 but was a bit scary.
Just got a spare tail, made it 10cm longer (so it won't go to minimum now). But, stiff as hell at "full" extension. Still on 190cm, but stiffer.
And alI have to do is carry that extra tail and only if the forecast is crap so I'm taking that one large sail

So why don't they make an extra tail at a reasonable price to include with new boom? Like an extra $200 or so for a long tail?

Mark, Hydodynamix did this 15 years ago.
We had arm extensions of about 300mm or 350mm from memory with another tail piece that simply attached with the normal clip arrangement.
Sold quite a few at the time as it was cheaper than buying an extra boom.
It always amazed me that people wanted their one boom to fit all their sails from 4.0M to 8.0M but they had 3 masts, 3 boards & numerous sails.

Just found this on the Duotone website...

^^^ They only care if it lasts a year though......... we would rather get more

What type of use? There's a lot of pressure landing backloops or sailing overpowered.
You will get increased flex and lose the benefit of carbon vs alu.
So I would get a less-expensive strong alu boom just for that sail.
It'll be a touch heavier but more responsive with less extension and lengthen the life of your carbon boom.