Tired of hearing how stiff brand so & so is.
No cut & paste or link to an advertisement here
Here's the challenge:
Manufacturers, retailers or punters.
Grab your so called stiff boom (carbon, fibreglass or alloy) & measure the flex at a max extension across the widest point.
Just stand on one arm & pull up on the other, not high tech but should give enough for a comparison.
Name the brand, diameter, model, size and amount of flex in mm.
If you are really brave add the price for comparison to stiffness
I'm guessing the silence will be deafening
Paul,
Great idea although to make it a little more scientific why not nominate a certain weight (say 30kgs) hung at widest point and measure the amount of flex.
That's exactly how I used to do it but figured I would be struggling to a response without making it complicated
I beleive it should be marked on a boom similar to IMCS on a mast.
Imagine that, a manufacturing standard
Easy to find the stiffest with this test. It'll probably be the heaviest and have the fastest grip..
A downwards pull on a clamped boom would test the flex in the arms and the flex in the head too.
Of course you'd have to specify lengths. No point measuring a wave on zero extension against a formula on full extension.
Tested (very unscientifically) an older Chinook 195-255? non monocoque carbon (not at full extension cause I couldn't be bothered pfaffing around with the adjustable outhaul). Flex at widest point was about 2.5cm.
Never felt that this boom was incredibly stiff.
German magazine SURF tested the mayority of booms currently available on the market. The results below come directly from this test.
Stifness in N/mm measured at 10 and 44 cm extension. The higher the values, the stiffer the oom is. All booms tested are in the 180-240 cm range.
Brand, model, price / stifness + 10 cm / stifness + 44
ALU
Aeron OS Slalom € 229/ 32 / 25
Aeron V-Grip € 249/ 31 / 19
AL360 Ergal € 299/ 26 / 22
Gun Expert € 239/ 24 / 19
NP X3 € 230/ 27 / 22
NP X6 hybrid € 449/ 28 / 23
North Sails Gold € 479/ 26 / 21
North Sails Silver € 289/ 22 / 21
Prolimit Assault V-grip € 249/ 31 / 25
Severne Race € 189/ 30 / 24
Unifiber Universal € 109/ 19 / 17
Unifiber RDG € 159/ 18 / 15
CARBON
Gun Select € 489/ 35 / 29
Prolimit RDG Team € 779/ 39 / 27
Gaastra Blue € 749/ 44 / 34
NP X9 € 999/ 46 / 39
AL 360 € 790/ 60 / 49
North Sails Platinum € 1239/ 65 / 60
Severne Enigma € 799/ 71 / 56
As you can see a proper alu boom is nearly as stiff as a cheap carbon boom. The magazine also noted that a hybrid boom with carbon back end doesn't add any stiffness or added value to the boom except the higher price.
C'mon snags, get the weights out and do the test on the MS Carbon.... Should do it myself but relying on your pursuit of a decent stiffy could save me the effort!
Steve,
I'll try and take some definitive measurements this w/e. Maybe at min, max and mid extension - this should hopefully provide some useful feedback.
I know before even doing it the MS carbon will be quite heavy but for peace of mind where I sail I'm more than happy to give up weight for durability.
The boom was clamped at both ends and they measured:
- the deflection in (mm)
- under a constant load 40kg at a fixed position from boom head
You get that magic number, stiffness N/mm!
Also of interest looks like the typical north marketting speak has some substance to it. The North Platinum is less stiff than the Severne Enigma at +10cm extension, but overtakes it once extended out to +44cm. That oversized tail must work!
Windless day here today so results are in. Just need to calculate figures based on Swoosh's and Remi's parameters. Watch this space................
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...