Reference for When to Change Countershaft Sprocket

FSprocket.jpgThe attached picture shows my countershaft sprocket after I removed it tonight.  The last time I rode my bike it was warning me that there were chain issues.  The chain was a bit loose so I had to tighten it 2 positions on the snails which is unusual.  When I took off the c'shaft sprocket guard it was obvious why the chain had stretched.

 

Don't let your c'shaft sprocket get this worn or you'll wear your chain!

 

A new sprocket goes on the bike tomorrow for what could be the last weekend of decent weather in Calgary.

 

Ian

Your chain and sprockets wore out as a set.  The counter sprocket did not do it all by itself.

 

A warn chain can take out new sprockets pretty quickly.  But actually a new chain on warn sprockets has little affect on chain life.  Still best to change all as a set.

 

If you are only looking for 1 more weekend, I would not bother to change that sprocket, then instal all new.

Yeah , people tend to let their sprocket's wear out and think they still look worn but ok .

When you compare a NEW sprocket to a used one , you really notice how bad the used sprocket actually is .

Mine regularly gets to that state of wear with no chain issues, in fact the one I have on now probably looks like that and I'm in no rush to change it just yet. Will possibly squeeze one more local ride out of it before changing.

Just keep your chain clean and well lubricated, that's the key.

Grab your chain at the rear of the rear sprocket and try to lift it off. If you can see much light between the chain and sprocket, the chain is shot too.

BTW, that sprocket is worn and should be changed, but a ran into a young man one day out in the boonies who's rear sprocket was so worn he could make no progress uphill. On pavement. That's a worn sprocket. Helped him tighten the chain to way too tight and told him to keep it to 30 or under and very light throttle. Pointed him on toward Kingman, don't know if he made it without more help. I was headed the other direction. Que' sera, sera.

attachicon.gifFSprocket.jpgThe attached picture shows my countershaft sprocket after I removed it tonight.  The last time I rode my bike it was warning me that there were chain issues.  The chain was a bit loose so I had to tighten it 2 positions on the snails which is unusual.  When I took off the c'shaft sprocket guard it was obvious why the chain had stretched.

 

Don't let your c'shaft sprocket get this worn or you'll wear your chain!

 

A new sprocket goes on the bike tomorrow for what could be the last weekend of decent weather in Calgary.

 

Ian

Ian, mine looked quite a bit worse than that....I'd be embarrassed to post a pic! My chain warned me also, when I ran out of adjuster range over a short period of time, but kept on riding as I didn't want to miss even one ride. As I ride too far into the boonies to contemplate a failure all the OEM chain stuff has been replaced, at around 14,000 km.

George, I can see light under my new chain/new sprocket!

 

Grab your chain at the rear of the rear sprocket and try to lift it off. If you can see much light between the chain and sprocket, the chain is shot too.

BTW, that sprocket is worn and should be changed, but a ran into a young man one day out in the boonies who's rear sprocket was so worn he could make no progress uphill. On pavement. That's a worn sprocket. Helped him tighten the chain to way too tight and told him to keep it to 30 or under and very light throttle. Pointed him on toward Kingman, don't know if he made it without more help. I was headed the other direction. Que' sera, sera.

A little common sense, Shus. I should have said, "...if you see MUCH light...". You know it's good now, so take a pic. Check it again each time you adjust the chain. In a few (or many, depending on your diligence) thousand miles, the diff will be obvious.

Most folks agree chains and sprockets should be changed out at the same time. Worn chain will reduce the life of the new sprockets and vice-versa.

(Just for reference, on my 95 VFR 750, I got 55,000 miles out of the original chain 'n sprockets. Doubt my DRZ will see that kind'a life but my ol' Yam XT-350 had 9000 miles on the originals when I sold it and they still looked good. :D)

Edited by George 99

A little common sense, Shus. I should have said, "...if you see MUCH light...". You know it's good now, so take a pic. Check it again each time you adjust the chain. In a few (or many, depending on your diligence) thousand miles, the diff will be obvious.

Most folks agree chains and sprockets should be changed out at the same time. Worn chain will reduce the life of the new sprockets and vice-versa.

 

I disagree with a lot of this.

 

Here's my take on this, looking at it logically...

 

A stretched chain will kill the sprockets as the pitch no longer matches.

Worn sprockets will not kill the chain as long as the correct pitch spacing is still maintained on the sprockets teeth. The drive edge may have receded but is has on all the teeth equally thus it's still at 520 pitch.

 

On a used system - if you can pull your chain off from your rear sprocket it means your rear sprocket is worn. It is showing you that you now have larger gaps between the sprockets teeth. It may also be showing you that there is wear between the rollers and the bushings in your chain. It is not a good measure of the condition of your chain.

If this test is carried out with a used chain on a fresh sprocket then it a good test for the chain. It is only showing you wear in your chain, even so it may just be showing you that the rollers are worn, the pitch may still be correct and thus will not harm your new sprockets.

 

Chains & sprockets wear with use but not necessarily at the same rate and thus not necessarily as a set.

If the chain has not literally stretched, the pitch will still be correct. If so then putting a used chain on fresh sprockets will be fine. The hard part is how to accurately measure the pitch of a used chain to see if it is still within tolerance.

Your bike's manual should quote a length figure for measuring the chain but accurately measuring that figure is not something I've accomplished yet.

 

This may seem like penny pinching to some as many road users will get 10,000 miles plus of out their chains & sprockets, in which case why not change the whole lot as one, I probably would just for peace of mind.

 

I get between 500 to 1,500 miles out of a front sprocket! In no way is the chain or the rear sprocket ready for replacement at that point.

If I have been running an alloy rear it will be well on it's way by 1,500 to 2,000 miles. My chains last 2,000 to 3,000 miles. Steel rear sprockets seem to be good for about 2 chains.

If I were to change all as a set it could get very expensive.

Yeah , I generally do 2 fronts to 1 steel rear sprocket .

I will say ... I notice the second front to chew out fairly quickly

I would think that measuring the chain would reveal what life it had left, even if the evaluation was somewhat subjective.

 

Noticed quite a bit of play in the links and the snail adjusters had run out of any adjustment when I pulled the plug. I have no idea if it's normal for a chain to wear fairly equally or for some links to be much worse than others.

 

Now I'm going looking for my old chain, with a tape in hand...

Edited by shuswap1

 

Noticed quite a bit of play in the links and the snail adjusters had run out of any adjustment when I pulled the plug. I have no idea if it's normal for a chain to wear fairly equally or for some links to be much worse than others.

 

That's only happened to me twice since using O-ring chains.

One was an RK that had a very hard life during a 2 week trip, was at around 3k miles and had just suffered prolonged use with caked on mud. It developed a tight spot (or loose spot) & I hadn't noticed so without realising it I was over tightening it and killing it quickly.

 

The other was a POS cheap brand O-ring chain which stretched with every use and took the sprockets out quickly also - that's how I know a stretched chain will take out good sprockets.

 

Most of my chains just deteriorate without physically getting any longer - the snail adjuster position stays pretty constant.

The chain can get kind of loose and side to side 'slappy', rollers may crack or go missing, O-rings can go missing. I generally change the chian long before any part of them goes missing BTW.

 

Just test your old chain against your new one by laying them out on the ground and see how far they will bend out to the side, that should show the wear in the pins & side plates etc.

Edited by DrzDick

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