I know them as split pins, cotter pins are something quite different, however my 1990 bike had one on the rear when new. I now have a later swingarm/wheel etc with 1" axle and that has a C-clip instead - much more fun if it gets away when taking it off!

I agree with Carl, that the front doesn't need anything like that.

 

Around here those are called snap rings.
I was in my 20's before I learned the right name for them.
My father always called them Jesus rings.
He told me they were called that because that is what you said when it went flying off to parts unknown in the garage never to be seen again!!!

 

The really odd thing about parts that go flying off and disappear, is when they REappear, days later, in the middle of the garage floor, in plain sight, in a spot you searched a dozen times. My theory is that nuts, snap rings and such enter a tiny wormhole in the time/space continuum. That's how they reappear hours/days/weeks later in a spot you've already looked. They've been time traveling in a worm hole.

All right, you come up with a better explanation!

 

I like yours but I have found that the time they come back is in direct correlation to when you get home with a new one.


Almost every time I replace a lost part the old one usually turns up right after I get home with the new one.


That is why I now buy extras!!!!!!!!!

 

It's the fairies f'in with ya. Happens to me too. I'll lose a tool or part, search for 2 hours, not find it, buy a new one and the other shows up immediately. The fairies laugh their *** off at you.

I was adjusting the timing belt tensioner on my Esprit (RIP) once. The socket slipped off the end of the ratchet and vanished. Now, you don't want to leave a socket laying loose in the engine bay of a car with an open, exposed timing belt and an interference design. A broken belt would cost about five large to repair, if you did the work yourself. I looked for hours. The next day, I started looking again, and there it was, trapped between some hoses and at a place I looked at repeatedly the day before.

The fairies like sweet things and shiny things. So put out a piece of candy and a little something shiny for them to look at. They just like to look. Do that and they will leave you alone, mostly.

 

It is a space/time warp thing. eventually it will warp back in.

 

That ^^^^, and when I set a tool down for ONE SECOND, and spend 20 minutes looking for the thing again, drives me nuts.

 

If I put out candy the mice would run the faeries out of Dodge.

 

The other day I replaced the rear brake lines on my dodge ram, after bleeding the brakes, I couldn't find my 5/16 wrench. Looked everywhere ten times! Then said uhh Ooooohh, must have left it on the bleeder nipple(snug fit) ,not there so back tracked on the roads that I test drove it on,with truck and again slowly on bike thinking I could see better, nothing as I thought... Just a little wrench but where was it ????
Next day the fairies came buzzing to me and said go open the hood again so I did and there it was next to the battery where I put it after topping off the fluid level before the test drive... or did the fairies need to borrow it and were too rude to ask. Leaning towards the latter.

 

I'm tellin' ya. Something shiny and something sweet.

My friend brought his 2nd gen RX7 over for a clutch job. That is not a small undertaking on that car. Anyway, during the reassembly, doing the transmission stabbing, the thing just would not go. After an hour or more of wrestling the thing trying to get it to go, it was pretty obvious the fairies were f'in' with us. I brought out something shiny and something sweet, set it out for them to see and we went back at the transmission. It went right in, first try.