A Cautionary Tale

Harley owners kind of think of the belt as a downgrade. Wouldn't be too quick to desire it. They'd also consider the loss of the kick start the same way if they'd ever heard of it. I called some Harley owner a retired doctor or lawyer on some forum and he came back with "who's retired?" Had a nice chuckle. XS650 rules supreme -- be proud.
 
Interesting thought experiment there... I'll pass.
Pass enough and it shows.

P.S. NO ONE would install a damaged clip. But please understand the clip will not come off, with or without wire, unless it's damaged! If it is damaged, wiring it to something that depends on an undamaged clip will not keep it on.
 
Last edited:
... But please understand the clip will not come off, with or without wire, unless it's damaged! If it is damaged, wiring it to something that depends on an undamaged clip will not keep it on.

Sure it will.
Take this example of a damaged clip.
Damaged clip.jpg


From this site:
https://thumpertalk.com/forums/topic/1035184-broken-master-link-clip-thingie-why/

It's easy to see how that damaged clip could eventually slide forward enuff to uncouple from the remaining master link post.

But, if it was safetyed, its remaining notch would remain engaged in the trailing master link post, hindering its forward slide. And the forward post would remain clipped.

There's a chain of events involved in the loss of the clip.

Natural motion of the chain, with its undulations and side whipping, places minor side loads on the master link's side plate. This can wear the clip's edge where it's retaining and contacting the inner edge of a post's groove.

The open end of the poorest clips have only a small contact area with the groove edge. Once that sharp/square contact interface starts to wear, the edges begin to round, leading to spreading and a chance of uncoupling with the pin's groove. When that occurs, the pin only needs to withdraw a tiny amount for the open end to loose its retention. Once that retention is lost, the clip can begin to slide. It can now slide enuff to disengage the remaining retention device, the closed end of the clip.

Break that chain of events, and the risk of failure is reduced.

The safety wiring prevents the open end of the clip from spreading. Or, in the case above, prevents it from rotating out of engagement with the trailing post. By arresting that particular motion of the clip, it can't uncouple from the trailing post, hence it cannot slide forward, leading to uncoupling of the forward post.

Edit: In addition to safety wire preventing the loss of the broken clip, above, safetying the clip during installation of the new master link and clip would probably have prevented the clip's breakage in the first place...
 
Last edited:
Note the clip is still on, without benefit of wire.
For all we know wire would have made it come all the way off. Vibration, slapping (well deserved), harmony of the spheres, what have you.
 
Last edited:
Well, this is really old-school stuff, developed, taught and practiced long before I got here.

The art of safety wiring is a world unto itself. There's even courses on the subject, offered at aviation training schools. For an idea of the complexity of the subject, Google "safety wire", and look at some of the examples. Most of those examples will depict safetying fasteners, bolt heads. But, the art also involves other archaic uses...
 
Bottom line -- maybe the wiring kept the clip from getting damaged. Nobody will ever know that. If the clip is damaged, the wiring it to itself you did will not help.
 
Sure it will.
It'll prevent the spreading of the open end, keeping it retained in the master link's pin grooves. Hence, it can't slide forward, leading to uncoupling of the other pin.

Edit: Also, by preventing the potential spreading of the clip's open end, the wear/rounding of the edge/corners of the clip and post/groove interface is greatly reduced. It's this rounding of those sharp corners that allows the pin/groove to wedge itself out of engagement with the pin/groove. By arresting that wear pattern, the chance of pin withdrawal and clip uncoupling is greatly reduced.

Maybe this will help.

 
Last edited:
Sure it will.
It'll prevent the spreading of the open end, keeping it retained in the master link's pin grooves. Hence, it can't slide forward, leading to uncoupling of the other pin.
Okay then, say it's a question of the effectiveness of the wiring re: the clip spreading. It's obvious it can never be tight enough to keep the clip from spreading wider than the post.
FWIW I did once read as thoroughly as I could about safety wiring, looking for a solution to a different problem. I can say from Jim's picture his technique is perfect -- the right rate, and the curly-Q at the end. But unfortunately it's wired to the breeze :D
 
Last edited:
Kinda with XJ here. :poke:
Improve the system :thumbsup:
Adding layers in an effort to band-aid a flawed system? not so much.
So if you use a clip it should look like this as showcased by 2many;
138285-ad9b32e47e865f5f89aac55243a5fd60.jpg

installed from the end and not deformed.
That extra wire sticking out just waiting to snag or be snagged by anything near by scares me more than a possible clip failure. :shrug:
 
Improve the system :thumbsup:
So if you use a clip it should look like this as showcased by 2many;
138285-ad9b32e47e865f5f89aac55243a5fd60.jpg

installed from the end and not deformed.
It looks okay. What I see is clip in contact with more groove which can only help. I'd like to see the same principle on the other post too if possible. How deep to make the groove would be an interesting problem I think. As you deepen it more you eventually start weakening the post, so how do you know when you have the best balance of clip retaining vs strength of post?
 
Pass enough and it shows.
You'll have to explain what that means... I'm drawing a blank. ;)
P.S. NO ONE would install a damaged clip.
... and yet that was your idea. Seems kinda silly now.....huh?
Note the clip is still on, without benefit of wire.
I think we can all agree that the clip is on but for the grace of god. When's it gonna fall off... 2 more trips around the sprocket... 20? As Steve pointed out, that's a case where the safety wire might have actually worked on a damaged clip.
Okay then, say it's a question of the effectiveness of the wiring re: the clip spreading.
AHHH.... now we're getting somewhere... ;) you're actually zeroing in on the point of the wire.... to stop the clip spread. Good for you! :D
It's obvious it can never be tight enough to keep the clip from spreading wider than the post.
:( Well crap.... and I thought we were gettin' somewhere. It's obvious? Really? It's not obvious to me... in fact it looks pretty damn tight. Just for s&g's, lets explore that...
304 stainless has a tensile strength of about 75,000 psi. It's yield is about half that. So.... a single strand of .032 has a tensile strength of about 243.3 lbs... feel free to double check my math... I might be off a tad. :rolleyes:
So we'll cheat the rest of the math and just call the yield about 125lbs. That's per strand... we wrapped it twice so that means the clip is gonna have to exert more than 250lbs of force before the wire starts to yield and let the clip start spreading.
At this point, I fully realize you don't believe nor trust this works. Me... I kinda like those numbers. :D .... and I'll continue to add the extra step whenever I install the master.
That extra wire sticking out just waiting to snag or be snagged by anything near by scares me more than a possible clip failure.
To bad you never went to one of my safety wiring classes. :sneaky: The ends are tucked under so they can't catch on anything... it's called a pigtail. When I was teaching, if a rag snagged on it or, heaven forbid... it cut the teachers hand, it was an automatic fail. :boxing:

So... I'll finish (yeah, I'm done. I'll let you know who have the last word) with another pointer and a quick story....
Mid to late seventies... Florida... flat tire on the RD350... crap. Pulled the back tire and walked/hitched a few miles to a gas station. When I got back, some yahoo had kicked my tools and bits out into the sand. Asshole. Anyway... found everything except the clip for the master. Suppose I coulda' looked longer but I needed to get home and ready for work. I always have some safety wire in my tool bag (it ranks up there with fuses and duct tape)... so here's what I did....

IMG_20190723_130210.jpg


Funny part is I clean forgot about it... remember I said it was the seventies... :smoke::rolleyes: The RD was my daily driver. About a week later I adjusted and lubed the chain... and noticed my half assed clip. Mental note to self... stop on the way to work and get a new master. yeah.... forgot... :smoke:
Chain lasted the rest of the summer. Bought a new one... it came with a new master. :D
Crazy? Hell, I was 25ish and indestructible. Worry 'bout a silly thing like a chain exploding on me? Never. :pimp:
I'm older and wiser now... but it just goes to show what a little safety wire will do.
 
Last edited:
I didn't expect to get this much response to this thread. When I saw the chain laying in the road it immediately took me back 40 something years ago ,turned around and saw mine laying on the ground behind me. Sinking feeling.

Funny when I first looked at 650s, I really liked the fact that there were two cylinders two carburetors and two sets of points I was in the middle of getting my private license when I bought it and so I really liked the redundancy. Thinking back I one lunged home more than once.

If the safety wired master link represents even a 10 percent reduced chance of not losing it then it’s worth the five minutes.
 
Back
Top