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New 15 tooth front chain sprocket question


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I bought a. New front chain sprocket today. It's 15 tooth like my last one, but the sprocket is actually bigger. Does nothing hold the sprocket in place on the gear? My old front chain sprocket had two bolts, but I took them off and determined they were only holds a plate on. But that plate is in no way attached to the bike, obviously. Is that little piece in the lower left hand side needed? It doesn't match my new sprocket to the left, so will I have to go and get one that fits. If so, I'm not surprised. Everything with this bike is a 2 trips to the part store, or more, adventure.

 

 

 

Image1496289816.897669.jpg

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Hard to explain, but if you look at the spline, the teeth aren't continuous. There's a groove that has no teeth. That's where the plate sits. It rotates so that the tabs hold inside the teeth on the outside portion of the spline. Email me at drewbug@gmail.com if you can't figure it out.

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Your old sprocket has 14 teeth, not 15 like the new one.  Count the teeth and see for yourself.

The sprocket is held in place by that little piece of metal under the old sprocket in your photo.  It slides over the splines after you put the sprocket in place, then rotates a tiny bit to fit into the groove on the countershaft.  That allows the sprocket to move just a little bit on the countershaft.  The new sprocket has four holes instead of two like the old one.  Find the two that match up with the clip and bolt the clip to the sprocket that way.

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Did you see the stamped "14" on the old one? Or count? Is the new an xr650r sprocket to help slow wear? Or order a fritz co sprocket made just for this. The plate that holds on sprocket has the holes offset a tad. Rotate plate in groove, until holes line up,and if holes dont line up, remove plate and flip over & try again. I did get a moose sprocket that was slightly miss machined and they made good on it, but a very rare situation. There is good info on history of the wear problem, search function is your friend. I plugged in "countershaft wear" and found a bunch.

https://www.thumpertalk.com/forums/topic/867817-xr650l-protect-your-countershaft-splines-with-an-xr650r-sprocket/?page=31

 

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I have multiple JT sprockets - same as the original poster - and they work just fine on my XR and on other bikes that I've put them on.
It isn't too hard to figure out which pair of holes the clip goes on that holds the sprocket in place on the countershaft.
 
Is this still a problem?  What is the perceived problem?



I need a new clip. The current clip doesn't match the new sprocket due to increased tooth size of "one". I don't understand how that clip holds that sprocket in place. I could see the chain holding it in place once fitted back together because there's no way a sprocket will pop off with that chain tension.
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The chain doesn't hold the sprocket on. The tooth count doesn't matter if its the right sprocket. Listen the the guys above... or ride it without the keeper plate, and send pics of the aftermath. Would rather you figure it out the right way though. Could you take the old sprocket off without removing the keeper? If the answer is yes, you have more problems.

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I say flip it cause the holes arent at exactly 3 and 9 o'clock. Theyre more like 8 and 4 oclock. So if you flip it, theyre at 10 and 2. Its very minimal, but they're not centered.

Maybe that plate is for that sprocket, and the CS hole/splines might be the same but the plates holes in the sprocket are different. Order an OEM plate...start over...JTs are good. I run one too. 

23811-MN8-000

Its not right if its this hard and you took the old one off. And saw how it does work.

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This clip discussion doesn't make any sense at all to me.

One clip works on all sprockets, regardless of whether they have 13, 14, or 15 teeth.  Find the two holes that line up with the clip so that it's centered over the opening where the sprocket slides onto the countershaft.  When the clip is lined up, the teeth should be directly out of phase with those of the sprocket and that's what holds it in place.

You don't want a front sprocket on there without the clip to hold it in place.  I broke a similar clip on a Ducati once and ended up chewing up the rear sprocket.  Then the replacement clip had something wrong with it and wore right through until it couldn't hold the sprocket in place, but I caught it before there was any damage.  It's the clip that keeps the chain properly aligned.  The chain by itself can't do it.

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This clip discussion doesn't make any sense at all to me.
One clip works on all sprockets, regardless of whether they have 13, 14, or 15 teeth.  Find the two holes that line up with the clip so that it's centered over the opening where the sprocket slides onto the countershaft.  When the clip is lined up, the teeth should be directly out of phase with those of the sprocket and that's what holds it in place.
You don't want a front sprocket on there without the clip to hold it in place.  I broke a similar clip on a Ducati once and ended up chewing up the rear sprocket.  Then the replacement clip had something wrong with it and wore right through until it couldn't hold the sprocket in place, but I caught it before there was any damage.  It's the clip that keeps the chain properly aligned.  The chain by itself can't do it.



Where did anyone say they were riding with out the keeper on? My question is mechanically how does the keeper keep the sprocket on? Both the sprocket and the keeper are attached to each other, of which they are attached to nothing other than the shaft. So I was just asking how the keeper works. The other guy is almost daring me to ride with out the keeper. My head is shaking, believe me. I don't know how things get so twisted.
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The keeper goes past the first set of splines into a grove, then when you bolt it to the sprocket, it twists alittle putting it out of line with the out side splines.  the sprocket will 'float' alittle side to side  to help keep ever thing in line

Edited by tucan
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The keeper goes past the first set of splines into a grove, then when you bolt it to the sprocket, it twists alittle putting it out of line with the out side splines



Thank you! That was a very long way to get an answer. I appreciate you bringing closure to this question.
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