Out of curiosity I went to no great expense to complete a rudimentary test on the different in single foot and conventional S fly rod guides on the flex of a rod. I took two identical bamboo skewer and wrapped a guide of each type in middle of the skewer. I inserted the butt into a proper size hole in a season oak board and secured a 1 oz. weight at the same point on the tip. The result was the skewer with the single foot guide flex 1/8 in. further than the conventional S guide. No futher testing is anticipated at this time unless a grant from the government is received to complete the work.