RE: Stop Formula XXL Sails!
The pros & other formula racers that have sore backs, do so because they try to carry the biggest sail possible for the wind conditions.
This means 9.0 to 10.0 sails in 25+ knots. Superman would have a sore back.
For the recreational formula racer / sailor like myself, I now resort to what is "reasonable and manageable" to finish the race. I have raced a 6.5 on my SB160 on a few occasions in 25+ knots, just so I could keep racing and finish.
I weigh 80kg and work on maximizing my efficiency with the smallest sail possible for the conditions. I have an 11.0, but spend more time on my 9.5 & 8.5 because they have much broader wind ranges than the 11.0. What I sacrifice by going smaller rather than larger is the deep downwind performance, a price I am willing to pay. I am not pro, so the only thing I risk if I rig too small, is the possible ego boost I may get by beating the other racers / sailors.
Formula 160; iSonic 111; HiFly Move 105; Tiga 263; '85 Mistral Superlight.
Maui Sails TR 11.0; 9.2; 8.4; 7.6; 6.6; Maui Sails Switch 6.0; 5.2; Maui Sails Global 4.5; 4.0.