New chain, old sprockets?

Discussion in 'The Garage' started by Flounder, Oct 25, 2013.

  1. Flounder

    Flounder Adventurer

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    I just picked up a BMW F650GS with only 4800 miles on the odometer. The previous owner looks to have never lubed the chain. I just happen to have a brand new Renthal chain sitting on a shelf. I inspected the sprockets and they look effectively brand new. Think it will be safe to install the new chain?
    #1
  2. bwringer

    bwringer Gimpy, Yet Alacritous

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    Personally, I think it would be fine.

    I've done something similar a few times on low-mileage old bikes -- the chains are always corroded to shit when you drag them out of the barn, but the sprockets are usually fine.
    #2
  3. Auto-X Fil

    Auto-X Fil Been here awhile

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    If the chain isn't worn, why replace it at all?

    I agree that it's ok to just swap the chain if the sprockets look fine. The worst-case scenario is accelerated chain wear.
    #3
  4. kubiak

    kubiak Long timer

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    I would do it no problem.
    #4
  5. LittleRedToyota

    LittleRedToyota Yinzer

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    i agree you will be fine.

    and like auto-x fil, i am also wondering...

    is there actually anything wrong with the chain?

    sealed chains don't actually need to be lubed. if it's just dry, keep running it. (go ahead and lube it if you want, but you'll just be setting it up to have an abrasive paste on it once the lube attracts enough dirt).

    if it is worn ("stretched") past the service limit or if there are kinks that you can't easily straighten with your fingers, replace it. but if you are just replacing it because it's dry and doesn't look like it is lubed, i would suggest not replacing it.
    #5
  6. Flounder

    Flounder Adventurer

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    The chain is a collection of finely pitted plates and it's got a multiple set of links that are really stiff. Even my best attempts to work some lube voodoo on it haven't helped.

    New chain going on.
    #6
  7. ibafran

    ibafran villagidiot

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    New chain should work fine. Still, lift the link at the very back of the rear sprocket and see how much daylight there is between the link and the sprocket? If there is very little movement and no daylight, you should be good to go. The chain should lay over the teeth with no lifting at all. That said:

    Examine the old chain closely and mark all the bad links. If you are lucky, there are only 3-4 and they are all in a row? Figure out how many links you need and go down to the bike shop to see the service manager. Many new chains come out of the box too long for the bike spec. Get enough cut-offs and rivet master links to fix the old chain for cheap. Sometimes the parts dept will sell chain off a large reel for cheap? Ask about that if you need a dozen links in a row. 4500 miles on chain with no lube and most of it should still be pretty good.

    The above assumes that you can check sprocket alignment and do all chain maintenance as per the book, etc.
    #7
  8. joexr

    joexr Banned

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    Some masterlinks and chains are different between brands , they don't all fit together. It's a safer bet to get the same brands.
    #8