The 1/8" is for for the ten speeds and up with derailers The 3/16" is standerd bike size and # 41 is heavyer and just a sliver wider and will work just fine,and should last longer.....they all are 1/2" picth.......CurtIt says on the interweb that #41 is 1/4" width. How does that relate to the 3/16" on worksman? does it matter what width it is? can 1/8 be used on the pedal side?