Richard - friction isn't unknown anymore. It's been measured. It's significant.
Look up my basal tied SRT Tip loading post. Stumpsprouts has it figured out.
Mathematically you multiply each stage's tension ratio of stages in series. So if you have a 1.2:1 ratio going around a pulley and then a 2:1 grinding over a rough bark crotch, 1.2 x 2 = 2.4 times more tension on one end of the rope than on the other.
Pulleys are very non-ideal as well. Even good sized pulleys as opposed to all the too-tight bend radius pulleys we tend to use.
Look up my basal tied SRT Tip loading post. Stumpsprouts has it figured out.
Mathematically you multiply each stage's tension ratio of stages in series. So if you have a 1.2:1 ratio going around a pulley and then a 2:1 grinding over a rough bark crotch, 1.2 x 2 = 2.4 times more tension on one end of the rope than on the other.
Pulleys are very non-ideal as well. Even good sized pulleys as opposed to all the too-tight bend radius pulleys we tend to use.
