sprockets and chains?

Originally posted by Jaybird
I spend far less time than the average rider does, yet I get far more life out of my stuff than most.

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How much life do you get out of your chains and sprockets? Do you replace them as soon as they aren't in spec or as soon as you start to see wear?

Eddie, I like to change out my chain before it gets to a point it will damage the teeth of the sprockets.
Last drive set-up on the KTM125 was a chrome moly CS, 7075-T6 rear, and a stainless plate/chrome moly pin&bushing chain, all from Krause(Sidewinder). I have approx 90 hours on the set and the chain is not at 2% growth yet, and there is no visiable change of any of the sprocket teeth.
Two DirtWeeks, many motos and practices, and a few woods.
I find it much more economical to change out the chain before the growth can damage the sprockets.
The set-up I mentioned above is a high-dollar arrangement, but I don't advocate spending mucho bucks like that. It was basically an experiment but you can get just as good of life out of standard stuff with the proper care.

Originally posted by sweden_345
Nope, Ironman doesnt sell chains (I think) but i run a X-ring chain. Last forever

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If you need to replace the sprockets every time you replace the chain and vice-versa why get an x-ring chain, unless you're running steel sporckets?

Originally posted by Jaybird
I find it much more economical to change out the chain before the growth can damage the sprockets.

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Unless I misinterpreted this, Jaybird is saying he doesn't change out the sprockets when he changes his chain. ?? Unless there is visible damage ??

I use the Sidewinder Titianium Series O-ring chain and sprockets with my 426 with great results. (Big bucks like JayBird said) I rode all of last fall and a week at Cooperland without making an adjustment. The Titianium O-ring chain is light and strong... Sweetest chain I have used to date, but very pricy. The sprockets are some kind of tool steel with the rear being lighter than the Stainless, but heavier than an Aluminum one. I tried Sidewinders Stainless rear sprocket, but was not impressed with it. As far as lubrication, I use a teflon based spray. It does not seem to attract dirt, but then again, I have not tried Jaybird's Juice. I'll have to be sure and give that a whirl at DW03.

O-ring vrs Standard chain... I may be full of roost, but I believe that I saw an article that dyno'ed the two and while initially, the freshly lubed standard chain consumed less horsepower than the O-ring, the lube broke down and the O-ring actually came out on top. (Bet they were not using JayBird's Lube) The article also mentioned something about the heavier O-ring chain being simular to adding weight to the flywheel. Beware though, I am pulling this info from deep within my cobweb infested knoggin.

327...you are correct, they were NOT using my lube! :)

Petroleum lube is what has been recommended for years by mfg's. As I've said before, petroleum lube uses film technology. The film must remain at a constant thickness to be effective. Motor oil has very little if any additive to help it stay adhered to the friction surface, and as a result, just centrifigul force can help to spread it thin.
Chain lube companies have placed additives such as tackifiers that help to keep the film in place, but many of them went too far with it. Take for example parafin based lubes...they are so thick and gooey that most of the good stuff can't even reach the friction surfaces before it goos up and becomes nothing more than a dirt spoonge.
I know folks love to spend big money on drive set-ups thinking that mo is bettah, but IMHO you can spend minimal money and have far better results by using the proper lubricant and maintaining your stuff properly. Many, (and I won't mention names like motometal :)) like to spend no time maintaining their drives...which is fine, to each their own. If you are happy with the year of good service that your set-up gives you with minimal maintenance, then so be it. I just maintain there is more to be had from a drive with proper care.

Eddie, you are basically correct...you don't have to change out your sprockets when you change a chain, as long as the chain isn't trashed. I sometimes will change out the whole set, but for other reasons than it being worn out. The logic behind telling people to change out the whole set is that many (read MOST) people are not really up on drive theory and what causes things to go bad, and as a result, more often than not, a persons sprockets will be trashed by the time they realise they have a badly stretched chain.

Look at it like Rich's fuel. He understands the concepts of fuel design and application, and as a result he is somewhat anal about how he goes about using fuel for different applications. Others prefer to fill up the plastic jug at the BP and go riding. Both Rich and the BP customer probably reach the same enjoyment level when straddled around a motor.

Now for some proof....which many want to see.....
I have a Timken testing machine that I have been trying differnt lubes on. I will be offering video of the actual tests and the printed results of lube vs lube.
I have also been building a test machine for chains. I hope to show the performance difference between different brands and grades of chains.

I'm not saying that super hard ti sprockets aren't good, I'm only saying that they aren't the best choice, and by far, not the cheapest route to go.
This I can garantee.....if one guy has an aluminum rear and the other has a steel...both with the same chain and ride the exact same hours and conditions, the guy with the steel rear sprocket will see his chain reach growth over specification far faster than the guy with the aluminum rear. Thing is, the guy with the aluminum will know he has a trashed chain by the condition of his sprocket teeth, the steel guy will keep thinking he has the bomb set-up, when in reality he has a trashed chain and is flirting with disaster. This will also be the guy who thinks you need to change out the CS sprocket more often than the rest of the set-up. The little sprocket can't take the stress of a trashed chain any more than an aluminum sprocket can.

One more question. What are the disadvantages or consequences of running a stretched chain or boogered up sprockets too long? You mentioned people getting 1 year out of their setup because they rode instead of paying more attention to their chain maint program. For example I rode my TTR for over 2.5 yrs with the stock chain & sprockets. Lots of mud and sand. It was obvious after year 1 that they were no longer in great shape but I still got another 1.5 yrs out of them. Never lost a tooth on a sprocket, broke a chain, had the chain come off or noticed any other ill side effects. I used 2 or 3 different lubes during that time and only tightened it when it looked ready to fall off. Seems to me that 2.5 yrs on the typically crappy stock chain & sprockets would be hard to beat. Heck a lot of people don't even keep a bike that long. Say you keep a bike for 4 years, at 2 yrs per set that only makes a guy actually replace them once, twice if he puts on another new set to sell it.

Yes I pay a lot more attention to my chain tension now but if I can get 2 yrs out of a set!

Ok this is more than one question but I do have another. Is there is a RANGE of proper chain tension? Say a person had a bike that had no rear supsension. Distance etc never changed. Would there only be ONE exact setting for proper chain tension? The way I see it, as long as your riding your bike and the rear supsension is moving up and down the tension is changing and there is going to be improper tension, stress and wear. Throw in chain slap, hard braking followed by WFO and it gets worse. Also throw in the fact that some of our bikes live in mud, water and sand and those chains/sprockets definitely have a finite life span. Even chains and sprockets used in applications where there is a chain tensioner, residing in an oil bath, never seeing sand, dirt, water or mud wear out and stretch.

Interesting, pretty soon I will have a 94 wr250 running to compliment my 94 yz. Since both bikes are very similar I was going to set up hour meters and start logging maintenace data. Although the different bikes will be used differently accuracy will not be that good but atleast I should know what would work for what.

I have a strange preconception that thebare bones yz will probably have a better wear/hour ratio because of the "ride 20 minutes and maintain the bike while waiting for your next 20 minute ride" atmosphere of motocross .Compared to the "ride 3 hours have lunch ride 3 hours go home take a nap and maintain tommorow" situation the "bullet proofed"wr will see. I will let you guys know in about 20 years when I think I finally have enough information to make a decent conclusion.

Eddie, look at your new handle and you will see why you haven't had any bad luck during that 2.5 yrs. on the same drive. If your chain is in fact worn, it gets loose...you've seen that when you have to tighten it. When it gets in that condition you are very, very lucky to not snap a link. I had a link snap on a road bike once and it was one of the scariest events I've had on a bike. I don't want to repeat such an event when trying a balls out triple with a dirtbike.

On chain tension...we have guides and rollers to help us keep the chain safe when it's at it's loosest point, that is if you have proper chain sag at the tightest point. Engineering dictates a fairly large window of chain sag for a stationary drive, but for our purposes I like to stay at the lower limits of 2-3% of the total distance between sprocket shafts. Let's assume your sprockets centers ar 2ft. apart...the chain would have proper chain sag(2%) if the chain sags down .48 inches from where it would be if the chain were stretched taught between the sprockets on top. Once we have this set, and the swingarm returns to it's normal position, the chain is way too loose to be proper. That is why we have guides and rollers to help things.  Chains too loose are bad news just as chains too tight are.
http://best-motorcycle-chain-lube.com/Chain%20Maint.htm#intitial-chain-adjustment

In theory, you can keep a chain drive running indefinately if you keep all of the asperities in the metal at the friction surfaces from breaking off. Shock load is the biggest contributor to wear on a properly lubricated chain that sees no dirt. (start/stop)

The chain will not stetch over time without any wear occuring, however there is a slight bit of elongating that the side plates do undergo upon initial breakin. This elongation is minimal on our size chains and shouldn't even be a consideration.

 

I run an X-ring chain because i have never had the need to replace my sprockets.

when I mentioned getting a season out of a setup with no maintenance I was being VERY conservative. Actually on my CR, it has two full seasons on it plus a bit more, and finally the front sprocket was shot. I replaced the chain and front sprocket not really looking at it or measureing it, but the realized I had moved the axle LESS THAN .100" from "new chain" position...the old chain would have been ok actually. The rear sprocket is pretty hooked and should be replaced soon.

Over two seasons with stock sprockets and no chain maintenance, pretty good in my book. I don't ride as much as I used to but still probably put average wear on the drive system as far as DRNers go considering the sand and mud here.

great posting Jaybird.

Eddie, if you really want to confirm where your chain tension should be, check it through the range of travel with the shock or linkage unhooked. To me, "ideal" chain tension is when the chain is snug but not tight at the "tightest" point of travel of the rear suspension. Once you establish this, put the shock back on and measure however it's convenient, write it down etc. It may or may not coincide with the book. On my CR for example I prefer to run it towards the loose side of the "book" range.


As a side note, the tightest point in chain tension would normally be when the axle, swingarm pivot and countershaft are all in a straight line, but we can't assume this because of the roller system (as Jaybird described). Note that sprocket size also has an effect on how much tension the rollers impose on the chain.

You make a very good point, Scott. The swingarm being in the same plane as the shafts does not mean that is the tightest point. Although it more often than not will be.

Now, on your chain....if the sprocket teeth were worn, why do you think the old chain would be "ok"? What do you think damaged those teeth? If the chain is measured and not worn past spec, then I suggest the chain was too tight. Just food for thought, if that is what thought eats.

Originally posted by motometal
Eddie, if you really want to confirm where your chain tension should be, check it through the range of travel with the shock or linkage unhooked.

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Yeah, I'm with you on that and from what I understand it seems to be especially true with the KTM's and everyone seems to believe that us KTM guys need to be running our chains a bit more loose than most. I did the routine with the shock off, didn't measure it but I cut a block of wood the proper size to fit in addition to doing the quickie reference with fingers.

Eddie, "everyone" is a pretty broad statement.
I disagree with the need for different tensions on different bikes. The fact reamins true for ANY bike that you need the proper sag at the tightest point.

What you may see however, is that with a linkless suspension the chain may actually be looser in the "on the wheel" position than a bike with a linked suspension. Chain tension should NOT be set during the on the wheel postion unless you FIRST set it properly then measure, or as you did, make a guage.

Yup, I might not have been very clear but we're on the same page.

FYI EVERY time I ever say EVERY, ALL, NEVER or anything similar, it's a good bet I just mean MOST, ALMOST ALL, NOT VERY OFTEN etc :)

Jaybird, I figure my sprockets wore out due to mostly just a lot of riding with a "somewhat" worn chain compounding the issue towards the end. The adjuster was only about .100" back from "new chain" position which shouldn't be bad at all, but I could tell a difference carefully looking at how the rollers contacted the rear sprocket (they were lagging a bit).

I remember when I was young running chains until there was no room left to adjust, then just removing a link and continuing on...of course, the bikes had a lot less power back then and the sprockets were all steel. Chain guides weren't as good, chains were jumping off all the time, those were the days....

I remember my friend's 79 cr125, it may have been missing the chain guide, the chain was always falling off, and we would be in the middle of nowhere. his chain would sometimes wedge itself between the countershaft and the case, usually there was a vice grips conveniently clamped on the frame of one of our bikes...we would put the vice grips on the flywheel nut (I think the ignition cover was missing as well?) and force the chain back out and continue on our way (until it did it again). what fun we had!