Kevlar has no advantage over spectra, polyester(dacron) or nylon straps that I observed when testing a few prototypes (none of the clew straps are all velcro, they use either spectra, dacron or nylon as the load bearing section and velcro just keeps it from loosening) .
Kevlar does have some disadvantages though. It's doesn't slide as easily as spectra. It degrades in UV exposure (if it's covered with the velcro, that will protect it) It's more expensive then the other materials.
The argument that Kevlar stretches less then the other materials does not apply in the case of the clew strap, as the load applied to the strap is such a small % of the breaking strength of the strap. I've yet to observe any stretch in the clew straps I have used (all using 1" webbing) and I've tried Kevlar, poly, nylon and spectra. The spectra was the best as far as sliding along the boom, with or without McLube sprayed on.
All the straps slid better then any of the lines I have used for tie downs. All the straps were easier and faster to rig/unrig then the lines.
Hi,
please remember the Laserclassrules:
By-Laws Part 2 Rule 3.(b):
"Control lines shall be natural or synthetic rope, EXCEPT that aramid fibre (f.e. KEVLAR) is not permitted for the BOOM VANG or CUNNIGHAM control-systems."
Ciao
LooserLu
Greg, then why are the related basic rules for the Clew Tie Down are under the headline "3. Control Systems, Control lines and Fittings" in the By-Laws Part 2??? So, is the Clew Tie Down a Fitting if it is not a Control-line? (For the JC-Clew-Tie-Down I can imagine, that it is a special fitting.)
Ciao
LooserLu