Sprockets - what is the 'life duty cycle'?

Discussion in 'Dakar champion (950/990)' started by BOB RAMSAY, Apr 28, 2012.

  1. BOB RAMSAY

    BOB RAMSAY Not in the Clique -

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    I have a '06 950. 19k miles and the sprockets look fine - so far.

    I have youthful experience with worn sprockets - buy I was young then and had better things to spend my $$ on. I know what to look for in worn sprockets and chain.

    I lube adequately (I think) - every 300-500 miles and I don't 'horse' on the drive train.

    I'm just curious how many miles some of you inmates are getting on their sprockets.

    Thx guys!
    #1
  2. mousitsas

    mousitsas Long timer

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    The 'secret' for long sprocket/chain life (apart from typical chain maintenance) is to change your front sprocket (the cheap one) frequently. Typically 2-3 times more frequently than the rear, as it wears typically 2-3 times faster. If I do that, then my setup lasts for 50k kms with typicaly one chain, 1 rear sprocket and 3 front ones. I use 17/45 combo to make use of max teeth count.
    #2
  3. WhereIsBobL

    WhereIsBobL Been here awhile

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    How do you judge the chain to be worn? Measurements? Adjustability? Bad links?
    #3
  4. BOB RAMSAY

    BOB RAMSAY Not in the Clique -

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    Other than when the chain is let go so far that it sags severly and the rollers are ready to fall off -

    refer to the manual. Measure the distance between 1 and 18 (link) pins. It should not exceed 272 mm. At that point, the chain is not only worn out - but stretched out.

    If your sprockets are worn, the teeth body will 'thin' and the teeth will take on a 'hooked' shape, starting to look like fish hooks. If your sprockets are gone - in all likely hood, the chain is also.

    I always heard: a worn chain will wear a new sprocket, and a worn-out sprocket will wear-out a new chain.

    Typically I replace as a set although I going to look into the above comment.
    #4
  5. BOB RAMSAY

    BOB RAMSAY Not in the Clique -

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    So, you're changing the front sprockets at 16.6 kms (approx. 11k miles)?
    Any indication of wear at this point?

    Thx - BR
    #5
  6. keener

    keener Speed changes you.

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    How does a worn socket wear out the chain?
    #6
  7. cjracer

    cjracer AWD please!!

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    I change everything about every 15,000 miles as a set (17/45). Better safe than sorry for my type of travel requirements. Been working well so far.
    #7
  8. Geek

    Geek oot & aboot

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    +1 .. every 15K I change out all 3.
    the last thing I need 60 miles away from the nearest cell phone service up a goat trail is to snap a chain.

    Cheap insurance. :deal

    YMMV: Chain life is very dependent on your riding style as much as anything.. if you are spinning up the tire and backing it into the corners, you are going to wear them more quickly. If you are commuting on pavement and riding smooth.. you can get them to last an impressively long time.
    #8
  9. Geek

    Geek oot & aboot

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    depends on what size socket you are using and if it is metric or standard :rofl
    #9
  10. dlrides

    dlrides 1:1.618 Supporter

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    This
    #10
  11. ridewestKTM

    ridewestKTM Long timer

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    I agree with what's been said, but I wanted to add some thoughts. The question "how does a warn sprocket wear the chain?" is worthy of thought. When sprocket wears, it wears inward making the contact points closer - shorter pitch- so as a roller is picked up it bears the load all the way around. But some where the next roller takes the load and because the effective pitch is smaller on the warn sprocket you get the chain links pushing against each other as they wedge into the smaller pitch. The point is the rollers maintain high loading all the way around as they follow the curve by rotating. High loan plus lots of rotation is accelerated wear. As the chain wears (clearance in the pins increases) the pitch gets longer - same problem different spot. Rust increases clearance and is the worst cause (IMO). New stuff there is a better sharing of the load and no self induced load.
    IMO - spend lots on the chain and chain lube (avoid rust at all cost) and it might pay for itself in at least you don't have to change as often, and always change sprockets at the same time.
    #11
  12. cjracer

    cjracer AWD please!!

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    My chain cleaning and lube habits are this:

    -Ride
    -when bike is dirty enough for a cleaning, hose off bike and chain.
    -Ride to dry off bike and chain.
    - Wipe down chain with WD-40 on a rag and inspect for any issues at that time.

    I use to use chain lubes in the past. They wasted too much of my time and money. Ended up getting flung all over the place and making a mess.

    I stopped the lube process, Put the lube money into buying high quality "O", "X", "W"- ringed (sealed), PLATED chains (GOLD DID for example). I have not seen any less in my chain life with lube than w/o.

    This again is my personal experience. Road riders v/s DIRT riders will differ greatly as GEEK said. If you need your chain to last 50,000 miles. Stay out of dirt, never go over 5,000 rpms and don't put luggage on bike.

    We go on trips and see guys lubing and cleaning there chain daily.

    -they put on lube, the lube picks up grit and dirt, they clean the grit and dirt off and put on more lube at the end of the day.....

    Less lube, less grit that gets picked up. Less time spent on this item and more time with a beer asking them what they are doing and what's the best chain lube.... :freaky

    Have a great weekend. :D
    #12
  13. mousitsas

    mousitsas Long timer

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    Visibly, I can tell that teeth are no longer symmetric.
    In the past I was changing sprockets and chain altogether but noticed that rear sprocket was always in much better condition that the front. However, most of the miles on my 950 are street miles and the offroad it sees, is exclusively hard surface with stones and little dust, which might explain the slow wear of the rear sprocket. No sand or half buried wheels etc on my way.

    I consider my chain shagged when on proper tension, more than half tooth is exposed as I pull the chain backwards from the rear sprocket.
    #13
  14. Geek

    Geek oot & aboot

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  15. bigkuri

    bigkuri Long timer

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    I'm on the verge of giving up on chain maintenance. I currently clean it with WD40 every 500 miles, and lube with wax. After 14,000 miles there is no sign of wear, and I'm generally pretty hard on the throttle and power. I reckon chains are now so good (quality ones) that maintenance is just something to make you feel less guilty and like you are making an effort.
    Last set on my XR lasted 20,000 miles, similar to my GSXR1.
    I change all as a set, not convinced of the merit of replacing the front sproket early, especially as you're putting it on a stretched chain.

    For me, and all my ham fisted wheelies, I think 20k miles is a pretty good change point.
    #15
  16. dlrides

    dlrides 1:1.618 Supporter

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    I too stopped lubing modern X-ring chains. I clean occasionally with a dry teflon spray from Lowes. IMHO sticky lube attracts foreign matter, causing premature wear. There is no way a spray lube can pass by the x-rings to the roller pins.
    #16
  17. ridewestKTM

    ridewestKTM Long timer

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    True but there's a surface between the outer part of the roller and the body pin that's not protected by the x-ring or (o-ring), but I do agree that this will not exacerbate the sprocket wear only reduce efficiency. Also I'm not convinced that the x-rings are so good that you'd take the risk of water getting in, whereas a good lube that's not too sticky might help stop rusting. It is an opinion issue and subjective to many factors including the lube quality.
    #17
  18. BOB RAMSAY

    BOB RAMSAY Not in the Clique -

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    Well put!
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  19. Masa

    Masa Been here awhile

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    I use 80W-90 gear oil and a paint brush to lube the chain occasionally after a ride. No rust and it keeps me happy.
    #19
  20. crashmaster

    crashmaster ow, my balls!

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    +1 This is exactly what I do. Change the front with each oil change, swap out the rear and chain every fourth time, about every 15,000 miles. Its a bit of over kill, but I dont like broken chains, kind of hard on the engine case. :lol3

    I dont use chain lube with the DID ZVMX X-ring chain either. I wipe the dirt off the chain with a diesel soaked cloth every couple of days, thats about it. IMO, with modern x-ring chains, lube does more harm than good.
    #20