Okay, kids fed and bathed and watching the idiot box.

Firstly I didn't have the exact parameters of the german test i.e. where the weight was hung from and where the deflection dimension was taken so I made it up on the fly.

Also I only used 32kg weight which was hung just aft of the harness line position. I don't believe the results between different size booms can be compared objectively although the MS Carbon (even though the biggest) is the stiffest if using the deflection difference at harness line position. Unfortunately I didn't take the mid deflection of the old Autima boom and its widest point is quite close to the head so the readings here are somewhat skewed (in its favour).

Details of each boom as follows:/Dead Weight / deflection at harness line 44cm ext / deflect at mid point 44cm ext / deflection at harness line 10cm ext / deflect at mid point 10cm ext
Autima Carbon 162 - 222cm /3.2kg (incl lines and uphaul) / 9mm (34.9N/mm) / no measurement / 6mm (52.3N/mm)
MS Carbon 190 - 240 cm /4.0kg (incl lines and uphaul) / 7mm (44.8N/mm) / 12mm (26.1N/mm) / 6mm (52.3N/mm) / 8mm (39.2 N/mm)
Unifiber 160 - 220cm Carbon 2.9kg (lines only) / 8mm (39.2N/mm) / 15mm (20.9N/mm) / 6mm (52.3N/mm) / 9mm (34.9N/mm)

What does all this mean?............................probably that I am a procrastinator and did this in lieu of jobs around the house

Select to expand quote

sausage said...
Okay, kids fed and bathed and watching the idiot box.

Firstly I didn't have the exact parameters of the german test i.e. where the weight was hung from and where the deflection dimension was taken so I made it up on the fly.

Also I only used 32kg weight which was hung just aft of the harness line position. I don't believe the results between different size booms can be compared objectively although the MS Carbon (even though the biggest) is the stiffest if using the deflection difference at harness line position. Unfortunately I didn't take the mid deflection of the old Autima boom and its widest point is quite close to the head so the readings here are somewhat skewed (in its favour).

Details of each boom as follows:/Dead Weight / deflection at harness line 44cm ext / deflect at mid point 44cm ext / deflection at harness line 10cm ext / deflect at mid point 10cm ext
Autima Carbon 162 - 222cm /3.2kg (incl lines and uphaul) / 9mm (34.9N/mm) / no measurement / 6mm (52.3N/mm)
MS Carbon 190 - 240 cm /4.0kg (incl lines and uphaul) / 7mm (44.8N/mm) / 12mm (26.1N/mm) / 6mm (52.3N/mm) / 8mm (39.2 N/mm)
Unifiber 160 - 220cm Carbon 2.9kg (lines only) / 8mm (39.2N/mm) / 15mm (20.9N/mm) / 6mm (52.3N/mm) / 9mm (34.9N/mm)

What does all this mean?............................probably that I am a procrastinator and did this in lieu of jobs around the house

you forgot to add the deflection of the mast under load in unison with the boom and the tightning of the arse hole in extreme conditions

^
I think you really need to have at least a handful of booms all the same size to make doing this test worthwhile. So manufacturers send those booms up to Yeppoon and I'll post some comparative results.

Wonder if there is a way to measure the carbon content of booms. I know they tell you with masts, but you never see anything on booms. I'm off to take a bath.

Select to expand quote

shear tip said...
Hi paul,

I'm not sure what your point is. Are you selling booms? Your avatar is flying the flag for Hydrodynamix, but you're not a site sponsor. Have you measured a hydrodynamix boom? How does it compare to the other booms listed by German Surf Magazine? Why not post some numbers - you seem pretty confident that other's "so called stiff" booms aren't...

My point is, I would like to see actual gear reveiws not advertisements.
Yes we manufacture & sell alloy booms made in Australia.
We are not a current sponsor on Seabreeze but were one of the first, actually the very first in the eastern sates many years ago, back when there was a limit of 4 sponsors for WA.
I haven't measured our booms for a few years but intended to do it on the weekend, didn't get around to it as we had wind, I will post results when I figure out the calculation.
I am not claiming our booms are better but I am prepared to post results which I would expect any manufacturer to do.
I have checked out a few brands & they are not stiff.
I compared a Chinook carbon against my old skinny alloy on Saturday & they were comparable, so as far as I'm concerned the Chinook is not stiff!

my GF says I'm stiff, and she weighs 40 kgs..... does it compare to chinook ?

So is the point that at the end of all this someone can stand on top of their castle and go mines the stiffest of them all

Select to expand quote

russh said...
So is the point that at the end of all this someone can stand on top of their castle and go mines the stiffest of them all

No, it's about being informed & buying a quality boom!

All that aside, recent enquiries would suggest that new carbon booms are very difficult to find. It is more a matter of buy what you can get!