head foil systems
Moderators: sderby, Tim Bosma, Tom Elsen
Re: head foil systems
We may be old but we're NOT that old We raced from 1979 to 2003 on "RUFFIAN" (O'Day 30) and the 170 really drove her! I think we are in for a HUGE surprise and may need to rethink our plans. What sizes and weights of headsails do you use? And what type? What a learning curve Keep the info coming - it's going to help.
Re: head foil systems
Nobody uses anything larger than a 155% anymore. That's also the largest size Genoa in the that size range allowed withoput penalty. This is from our PHRF bylaws and fairly typical:
"APPENDIX - C
ADJUSTMENT GUIDELINES
1. Sails:
a. Headsail adjustment is based on the largest genoa and is determined by the LP/J ratio stated as a percent. From 136% to 155% requires no adjustment, 156% to 170% the adjustment is -3 seconds, 171% to 180% the adjustment is -6 seconds. Over 180% the adjustment is assessed at the option of the Board. Headsail credit is +3 seconds for 135% to 111% and +6 seconds for 110% and smaller.
As to weights and such, that depends on the fabric and building method. The 7.9 class rules allow any material as long as the sail meets minimum weight. Since a laminate sail that uses Mylar, Kevlar, Technora and/or Carbon fibers is WAY stronger for a given weight than any woven Dacron or Pentax, building one to the class minimums means that the sail is almost stretch proof, with ALMOST being the key word! Any sail will stretch if used in too much wind and/or abused by flogging and/or being backwinded into the spreaders too much and too often.
"APPENDIX - C
ADJUSTMENT GUIDELINES
1. Sails:
a. Headsail adjustment is based on the largest genoa and is determined by the LP/J ratio stated as a percent. From 136% to 155% requires no adjustment, 156% to 170% the adjustment is -3 seconds, 171% to 180% the adjustment is -6 seconds. Over 180% the adjustment is assessed at the option of the Board. Headsail credit is +3 seconds for 135% to 111% and +6 seconds for 110% and smaller.
As to weights and such, that depends on the fabric and building method. The 7.9 class rules allow any material as long as the sail meets minimum weight. Since a laminate sail that uses Mylar, Kevlar, Technora and/or Carbon fibers is WAY stronger for a given weight than any woven Dacron or Pentax, building one to the class minimums means that the sail is almost stretch proof, with ALMOST being the key word! Any sail will stretch if used in too much wind and/or abused by flogging and/or being backwinded into the spreaders too much and too often.
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Re: head foil systems
We use a foil on Frequent Flyer #538. We also use a harken Carbo Foil on our 30 footer. To use on not to use one is ones own decision. What works best for you.