Clutch worm mod tests, summary.
Quantify these tests, score them, and include them with the previous scores.
Config #10 - 'Yella Tracker', short cable, stock XS worm, 1.35" clevis hole distance
Config #11 - 'Yella Tracker', short cable, modified worm, 1.3" clevis hole distance
Config #12 - 'Bug Killer', stock XS worm, 1.5" clevis hole distance
Config #13 - 'Bug Killer', modified worm, 1.45" clevis hole distance
Closely examining the 'pull' pics, matching pull distances, averaging readings:
#10: Pull-test = 17.8 lbs, Actuator travel = 0.064", Cable tension = 97 lbs
#11: Pull-test = 17.5 lbs, Actuator travel = 0.061", Cable tension = 95 lbs
#12: Pull-test = 10.0 lbs, Actuator travel = 0.059", Cable tension = 60 lbs
#13: Pull-test = 9.5 lbs, Actuator travel = 0.057", Cable tension = 57 lbs
The scoring scheme is: Mills (0.001") per pound of lever pull, scoring factor:
#10: Travel = 0.064", Pull = 17.8 lbs, Mills/lb = 3.6
#11: Travel = 0.061", Pull = 17.5 lbs, Mills/lb = 3.5
#12: Travel = 0.059", Pull = 10.0 lbs, Mills/lb = 5.9
#13: Travel = 0.057", Pull = 9.5 lbs, Mills/lb = 6.0
Finally, sort the list by score, highest score first:
# Score Travel Pull Description
#13: 6.0 0.057" 9.5 - 'Bug Killer', modified worm, 1.45" clevis hole distance
#12: 5.9 0.059" 10.0 - 'Bug Killer', stock XS worm, 1.5" clevis hole distance
#10: 3.6 0.064" 17.8 - 'Yella Tracker', short cable, stock XS worm, 1.35" clevis hole distance
#11: 3.5 0.061" 17.5 - 'Yella Tracker', short cable, modified worm, 1.3" clevis hole distance
And, for comparison reference, the previous scoring table:
#9: 4.1 0.058" 14 - Ultimate XS worm, 1.65" clevis hole distance, mod cable entry angle
#4: 3.9 0.051" 13 - XS worm, arm bent down 0.5", 1.7" clevis hole distance, mod cable entry angle
#7: 3.9 0.062" 16 - MikesXS worm, arm bent down 0.5", 1.20" clevis hole distance, mod cable entry angle
#2: 3.6 0.064" 18 - XS worm, arm bent down 0.4", 1.3" clevis hole distance
#3: 3.3 0.046" 14 - XS worm, arm bent down 0.5", 1.7" clevis hole distance
#8: 3.1 0.040" 13 - MikesXS worm, arm bent down 0.5", 1.60" clevis hole distance, mod cable entry angle
#5: 3.0 0.045" 15 - MikesXS original worm, 1.35" clevis hole distance
#6: 2.8 0.034" 12 - MikesXS original worm, 1.75" clevis hole distance
#1: 2.5 0.062" 25 - Stock XS1 worm, 1.3" clevis hole distance
Well, it appears that this worm arm rebend mod provides no significant improvements whatsoever on DogBunny's bikes. Disappointing, but this is the purpose of these tests. On the surface, this mod appears to have merit, but maybe only so for particular configurations. Perhaps this mod is only effective when used as part of an overall clutch actuation tune-up. The high scoring value of DogBunny's 'BugKiller' clutch setup is promising, the new 'achievable' target. As for the arm rebend mod itself, for now we'll let the XS community decide.