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Replacing a bend shifter control shaft

Posted: Mon May 30, 2016 9:31 am
by Ajf
I'm replacing a bent shifter control shaft and noticed the ball receiver may need replaced too. Does this look like its bad or can it be used?
image.jpeg

Re: Replacing a bend shifter control shaft

Posted: Mon May 30, 2016 10:55 am
by viclioce
Looks like quite a few dings in the surface. If you have it, I would replace it. Just for smoother shifting if no other reason. ; D Victor

Re: Replacing a bend shifter control shaft

Posted: Mon May 30, 2016 11:54 am
by Bullfrog
That ball receiver would probably still work just fine - but why take the chance? The new part is not very expensive and putting in the new one right now will be easier than going "back in" later to replace it if you find it doesn't work all that well. So here is another vote for replacement now.
Ed
PS: The new one will have the "dings" just like that one after a day's worth of riding.

Re: Replacing a bend shifter control shaft

Posted: Tue May 31, 2016 6:26 am
by ---
Has anyone ever tried case hardening the ball receiver? Just a thought.

Re: Replacing a bend shifter control shaft

Posted: Tue May 31, 2016 8:26 am
by Bullfrog
While I'm not a metalurgist, I'm under the impression that case hardening would tend flake off under the relatively high "point" loads of the balls against the ball receiver. While the "dimpling" of the surface of the ball receiver in the photo can cause concern, experience indicates that it is not a problem. A primary consideration is that the shallow "valley" on the OD of the ball receiver must be there for ball receiver to do its job.
Ed

Re: Replacing a bend shifter control shaft

Posted: Tue May 31, 2016 9:50 am
by ---
The dimpling is a form of work hardening, similar to shot peening. Case hardening is not a surface application. It tempers the metal but not all the way through. I was just thinking that since the receiver work hardens anyway, why not start with a hardened ball.

Re: Replacing a bend shifter control shaft

Posted: Tue May 31, 2016 11:23 am
by bchappy
I would guess the ball that are pushed out in the gears by the ball receiver are hardened. So I wonder if two hardened metals against each other would be a problem. Usually you don't want two like metals rubbing against each other.

Re: Replacing a bend shifter control shaft

Posted: Tue May 31, 2016 5:23 pm
by ---
A ball bearing is hardened to a standard that you really can't duplicate at home, so even if the receiver were "hardened" by heat or whatever, I don't think it would approach the hardness of a high carbon heat treated ball bearing.

Correct, you should not run two metal of the same hardness if they impact each other. I am just thinking a bit of durability in the receiver might make for crisper shifts and longer life. If no one has tried it, perhaps I will when I rebuild the Webco 125.