It keeps the rear axle nut from changing it's torque over time, which could either cause the rear axle nut to bind and strip when you go to loosen it, or it could cause it to loosen up and let the axle slide, changing the alignment of the rear tire and leading to a rather nasty wreck. Rather than cotter pins that have to be replaced constantly, you can use a hitch pin (any Home Depot or Lowes or ACE should have them)...you can use the same one for years, and one whack with a wrench will set or unset them, so they're much faster / easier to use, and they're only marginally more expensive than cotter pins.why the frick is this on there?
any real reason why i should keep it on the axle?
I had a Honda F4i and it has a self locking nut, you have to torque it pretty tight, I imagine the Yamaha would be the same.so ive only seen these on gixxers and kawis, what bout honda? yamaha? are they castlenurt