Regarding the CS spline wear issue...

[EricV]

OK guys- feel free to laugh, at the drawing below and at this feel out. Seriously- have fun w/ it as I’m no engineer nor a metallurgist. Just spitballin’ here. I’m pretty frustrated w/ this CS spline issue. I’ve got about 14K on the TE630 now and sure enough my splines are getting more and more worn (using OEM sprockets, aside from one from Drive Systems.) Let me also say in advance that it’s not the purpose of this thread to review and belabor all of the ins and outs of the issue- for that you can go to:

http://www.cafehusky.com/threads/disgusted.39509/

I am convinced that the wear on the splines is most attributable to side to side slop. So not rotational slop (though that sure doesn’t help)- but actually along the splines… wherein the sprocket “vibrates and migrates” along the splines (even a miniscule amount) and this is what wears them. This seems to be the case with mine, based on the marks I am seeing under close magnification. A new c-clip is supposed to help w/ this, but I don’t see how it can or does.

Like others I really wish our set-up was a bolt on CS sprocket. I’ve stared and stared at this thing trying to envision what may work. So again feel free to laugh at my “drawing” (seriously- it bites) but I think you’ll get the gist of what I’m thinking. Obvious note being that all needs to abut very closely to eliminate any migration.

Now again I couldn’t be any further from a metallurgist, which is why I’m soliciting opinions here before wasting my time talking to a machinist. My guess is that the drive shaft itself is too hard to modify, or that such a “notching” may weaken it to the point of failure. It’s also unlikely it can be tapped/threaded, or helicoiled (as I know nothing about these practices, to be honest.) It just seems to me that w/ that big ‘ol hole in the middle there must be some way to do a bolt on type of thing…some type of immobilization.

I also get that it’s probably a waste anyway. If mine holds up, say, another 10K then it’s just as likely I’ll be due a case splitting anyway. Still, I don’t like all of the slop I have and I know that once it’s begun the wear accelerates faster and faster (as it’s going in beyond the hardening surface.)

 

[DYNOBOB]

I like this - except I wonder if you could just drill/tap the hole and use a specially machined washer with shoulders deep enough to tighten against the sprocket. Forget the clip.

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[EricV]

I like this - except I wonder if you could just drill/tap the hole and use a specially machined washer with shoulders deep enough to tighten against the sprocket. Forget the clip.

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Thanks for replying Bob. That could be a simpler improvement for sure.

I'd sort of thought of that also, in that I was thinking "hmmm, how 'bout right behind the clip there would be a super thin washer to avoid the lateral vibration/migration issue." I ditched that line of thinking, though, because we want to be sure the clip is fully seated in it's groove.

I guess I was thinking of the bolt on "cross member" because the rotational slop has to also contribute to the wear on some level.

Now in all seriousness it's probably a bit too ambitious to take on (as a realistic mod) but again I'm thinking my CS isn't long for this world...so can't help but think forward to what's possible to prolong it's life or- in the event of choosing to replace it- how to mod it to avoid a new CS from being toasted.

In about an hour (if the storms hold off- don't have a garage) I'm going to put on a new OEM 14T (and new chain), but I'll imagine that'll still have appreciable slop as the wear in the splines is now visible. If I could go back in time- to when I bought the bike- I'd have sprung for a cush hub. But, alas, I have no DeLorean nor any access to a decent flux capacitor...darn it.

 

[ghte]

Interesting line of thought Dynobob. I only have 1500 kms on my machine and am thinking an early intervention could be a good idea. I would love to know if you go ahead and tap and thread the spline and how it works in the end.
I was thinking a large headed bolt on nylon washers to apply some lateral cushioning might be a consideration. ( the bolt could be machined if necessary).

Good luck if you follow through

 

[mekanik]

And should it be LH thread so loosening isn't an issue?

 

[DYNOBOB]

No, standard thread. The countershaft turning forward will be trying to tighten the bolt.

It would require a machinist, but what I have in mind would look like a small teacup that slips on the cs and contacts the sprocket just before it bottoms against the cs. There's a reason why street bikes all have bolts on the sprocket...

I bet the cs is some hard metal, wonder if you could even drill/tap with hand tools. Would be nice to practice on a trashed one first.

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[EricV]

I bet the cs is some hard metal, wonder if you could even drill/tap with hand tools. Would be nice to practice on a trashed one first.

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Yeah- this. I wonder also. You're right- a trashed one to guinea pig would be great. Not sure what Ken decided to do- maybe he's got a used one out now (as his was so far gone some time back.)

 

[motranqui]

I am convinced that the wear on the splines is most attributable to side to side slop. So not rotational slop (though that sure doesn’t help)- but actually along the splines… wherein the sprocket “vibrates and migrates” along the splines (even a miniscule amount) and this is what wears them. This seems to be the case with mine, based on the marks I am seeing under close magnification. A new c-clip is supposed to help w/ this, but I don’t see how it can or does.

I’m not sure if I've understood (sorry, is a matter of the language and so sorry if I say a silly thing) but if you're concerned about the movement along the spindles, why don’t you order to a turner a thin washer made of a hard metal to put it between the CS and the C ring?

In my case, barely there is no movement along the spindles… may be a really tiny movement.
I know it's not a brilliant idea, but may be could work

 

[EricV]

No problem- you're understanding what I was saying perfectly fine...all good.

Yes, I believe it's migration along the splines and in hindsight would've gone the thin washer route. But that's just it: hindsight. With a new sprocket and clip the tolerance is very thin- feeler gauge thin. I didn't believe it at first, but a new clip makes a difference- I think the clip does wear thin over time. Still, I have wear/slop, now, but changing more frequently than normal will help a bit.