I recently got a new Dakine Fusion kiteboarding seat harness. An interesting label was attached to the black painted aluminum spreader bar included with the harness:
"THIS SPREADER BAR IS NOT INTENDED FOR KITESURFING."
ALUMINUM SPREADER BAR
http://www.dakine.com/frontend/catalog. ... 050-511-22
I was sufficiently intrigued by the possible explaination for this message that I gave the Dakine folks a call to ask about it. They indicated that Dakine now had purpose designed and build spreader bars for kiteboarding of STAINLESS STEEL, shown below. I hadn't heard specific stories about many spreader bar failures but wondered if this had something to do with it. Dakine indicated that yes, given the substantial loads that can occur in kiteboarding that there had been spreader bar failures or breakage during kiteboarding sessions with aluminum spreader bars.
STAINLESS STEEL SPREADER BAR
PIVOT SPREADER BAR
Stainless steel can have an ultimate or breaking strength per unit area of about 4 times greater than aluminum. Also aluminum can suffer a fatigue or cyclical failure sooner than stainless steel. Kiteboarding can introduce some dramatic short term and periodic stresses. Enough to cause metal to fail and not just aluminum either.
Remember the recent threads about using kiteboarding gear in unusual high altitude applications and concerns about ready failures or breakage of materials? This is just one more example. Kiteboarding is definitely not as easy as it looks. Paragliding occurs in a much more demanding environment in terms of required strength of materials, pilot training and selection of appropriate equipment.
Look over your gear periodically and if you are in doubt about the strength of a component consider replacing it, soon. Stainless steel spreader bars have also broken it seems once in a while. It might be good to move up to a good stainless one if you are currently using aluminum as they should have a longer service life than aluminum, ideally.
SZ is right, swimming can suck. Stranger and potentially more damaging things can happen with sudden gear failures than just swimming too. So, checkout your stuff, it can change sometimes.
<font size=-1>[ This Message was edited by: RickI on 2003-01-26 15:19 ]</font>