chain ring replacement: cost effective?

Discussion in 'Cycling Equipment' started by G.Daniels, Mar 5, 2003.

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  1. G.Daniels

    G.Daniels Guest

    the l980's SR chainrings are wearing small ring first. Is replacing the small ring cost effective
    given the different wear and thus chain stretch between large and small,now new, rings? or does the
    larger diameters of the chain rings as opposed to the more rapid wear over the smaller rear gear
    cluster cancel the two different chain stretchs out uh somewhat? So I'm seeing 3000+ miles from a
    cluster and chain with the different unreplaced wear patterns. Do the new inner and worn outer rings
    give a reduction in that 3000 mile useage?
     
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  2. David Kunz

    David Kunz Guest

    g.daniels wrote:
    > the l980's SR chainrings are wearing small ring first. Is replacing the small ring cost effective
    > given the different wear and thus chain stretch between large and small,now new, rings? or does
    > the larger diameters of the chain rings as opposed to the more rapid wear over the smaller rear
    > gear cluster cancel the two different chain stretchs out uh somewhat? So I'm seeing 3000+ miles
    > from a cluster and chain with the different unreplaced wear patterns. Do the new inner and worn
    > outer rings give a reduction in that 3000 mile useage?

    I replace CRs as they wear -- when the skip under load with a new chain. The middle wears the
    fastest for me (usually 3 or 4 chains), then the small, and I've never replaced a big one from
    riding wear (dang those rocks :)).

    David
     
  3. Paul Kopit

    Paul Kopit Guest

    On 5 Mar 2003 09:27:26 -0800, [email protected] (g.daniels) wrote:

    >the l980's SR chainrings are wearing small ring first. Is replacing the small ring cost effective
    >given the different wear and thus chain stretch between large and small,now new, rings? or does the
    >larger diameters of the chain rings as opposed to the more rapid wear over the smaller rear gear
    >cluster cancel the two different chain stretchs out uh somewhat? So I'm seeing 3000+ miles from a
    >cluster and chain with the different unreplaced wear patterns. Do the new inner and worn outer
    >rings give a reduction in that 3000 mile useage?

    Your chain wear is directly related to how and when you clean the chain. 3,000 miles is good for a
    chain and poor for the cogset. I'd only guess that the chain needs replacing before the 3,000 miles.

    If the small ring is worn, evidenced by being very noisy or skipping, then you can replace that
    ring. The noise can sound almost like front derailleur rub or grinding. You might also just turn the
    ring over and mount it again. Smaller rings wear faster. On a triple, the middle ring frequently
    wears first because it gets used most often.
     
  4. Bruce

    Bruce Guest

    g.daniels wrote:
    > the l980's SR chainrings are wearing small ring first. Is replacing the small ring cost effective
    > given the different wear and thus chain

    There is no need to replace a chainring unless the chain is jumping, or you have trouble shifting
    etc. While a worn chain will cause increased gear-wheel wear, due to uneven loading, the reverse is
    not true. The larger ring will wear more slowly, and tolerate more wear before it starts to jump.

    > stretch between large and small,now new, rings? or does the larger diameters of the chain rings as
    > opposed to the more rapid wear over the smaller rear gear cluster cancel the two different chain
    > stretchs out uh somewhat?

    I dont think you are making any sense there. Have a read of Sheldon Brown's page on so-called
    "chain-stretch".

    > So I'm seeing 3000+ miles from a cluster and chain with the different unreplaced wear patterns. Do
    > the new inner and worn outer rings give a reduction in that 3000 mile useage?

    No, not according to my understanding or experience. But I'll bet someone disagrees. If so, I'd like
    to hear the explanation.
     
  5. Ron Hardin

    Ron Hardin Guest

    Bruce wrote:
    > The larger ring will wear more slowly, and tolerate more wear before it starts to jump.

    The difference is that the chainring takes on links under load and the freewheel cogs do not. The
    tip of any would-be hook is what is worn off on the chainrings, but not the cogs.
    --
    Ron Hardin [email protected]

    On the internet, nobody knows you're a jerk.
     
  6. Peter Cole

    Peter Cole Guest

    "Ron Hardin" <[email protected]> wrote in message news:[email protected]...
    > Bruce wrote:
    > > The larger ring will wear more slowly, and tolerate more wear before it starts to jump.
    >
    > The difference is that the chainring takes on links under load and the freewheel cogs do not. The
    > tip of any would-be hook is what is worn off on the chainrings, but not the cogs.

    A more obvious difference is that chainrings are much larger.

    Chainring hooking is common, it causes chain suck.
     
  7. Bruce

    Bruce Guest

    Ron Hardin wrote:
    > Bruce wrote:
    >
    >> The larger ring will wear more slowly, and tolerate more wear before it starts to jump.

    I was comparing the two chainrings there, but guess it applies to comparison with the cogs too.

    > The difference is that the chainring takes on links under load and the freewheel cogs do not.

    But the cogs "take off" the links under load. Wouldn't that have the same effect? How does wearing
    differ? The loading on the links & teeth is symmetric. Wear is caused by friction under load, and
    the direction of movement wouldnt matter. Its the size of the rings that makes the difference IMHO.

    > The tip of any would-be hook is what is worn off on the chainrings, but not the cogs.

    You reckon? I find that hard to believe. Havn't observed it, but then I lack your experience.
     
  8. Paul Kopit

    Paul Kopit Guest

    On Sat, 08 Mar 2003 10:55:10 +0800, Bruce <[email protected]> wrote:

    > The loading on the links & teeth is symmetric.

    Logical but not true. Charings wear more at the 1 o'clock position where you start the bicycle and
    few riders apply even pressure all around. You can rotate a ring that is skipping a couple of holes
    and find that the skip it gone or lessened.

    Chainrings can be worn and not skip at all. I used a set of rings on the timing side of my tandem. I
    turned them over 180 degrees to maximize use. The engagement of the teeth was not perfect and never
    skipped but the rings were noisy. I replaced those 2 rings and happened to use one of the worn rings
    on a single. There was zero skipping but the noise of engagement sounded almost like grinding.
     
  9. G.Daniels

    G.Daniels Guest

    OK! the premise was that the chain as NEW and the rings as NEW----- MATCH then the rings wear(slowly
    thanks) you wanna hear grinding noises think of CR's wearing like gear clusters. so the CR's wear
    and wear and then one day you clean them and say holy ...... batman we need a new inner CR(cause the
    '83 SR belonged to a woman and the sea breeze is a 50% grade so stop snickering) HOWEVER, the
    thought occurs that the total wear on the CR's now exceeds the cost effective replacement when mated
    to a new chain/gear cluster in other words wear with a tight inner and a loose outer CR-that is
    asking the chain to pull at one new dimension then pull on one worn dimension wears the chain much
    more than the almost equally worn inner and outer now on the frame. whew! the ratio of wear on
    everything new vs the ratio of wear on everything worn but with a new chain und cluster vs the ratio
    of a new inner CR, new chain/cluster, old outer CR. whew! the question is not moot as SR's are good
    CR's and go maybe 10,000 miles with care while I'm not so sure that's the situation with lesser CR's
    and i have two sets(with more used around here at terminus somewhere) so getting a new inner and
    swapping back to the next set is cool( and the sugino's-check the site!-are dear i'm told). i assume
    as no sentinent life form rose up to say "THIS IS A unghfoil L;OUSY IDEA" then the new inner will
    run.no tooth grinding can anyone here give an engineering explaination/description of bearing
    retainers at the headset?
     
  10. G.Daniels

    G.Daniels Guest

    maybe the new ring shud be broken in with a half used, at less than 1/16", chain?
     
  11. G.Daniels

    G.Daniels Guest

    further mulling! if itwernt cost effective down at the wagon factory, the replacement ring wudbe cut
    or ground more to the worn large rings spec., no? gives rise to the idea, if this is an idea I'm not
    sure... anyway the measure of a new tooth top vs the measure of the worn rings top vs the measure of
    the large rings top shud yield an averge that rationally produces cost effectiveness in not
    streeeectctching the chain unduly- that is to say without going to the trouble of actually looking
    at the chain ring tooth tops as a continuing maintenance function (is this boring?)maybe the worn
    ring shud be replaced before the tooth tops are worn to a point My first wonderings about this were
    answered by bikemags photo of the longrangeHoffman holding up worn chain ring number 37 and LO! the
    teeth wear worn to points.In fact,given the fleeting nature of most bike mechanic's contact with
    specific bikes and the unlikely natute of having 37 worn rings pass through maybe Hoffman's mechanic
    is one of the few people on this side of the planet with empirical knowledge? SOURCE!when I noticed
    tooth wear approaching terminal velocity, Harris Cyclery was dialed up and Harris's ring scroll much
    like that from Sparticus or GTW brought a healthy laugh 'cause there they are!Amazing. If you
    enjoyed redaing this try DIY bike/cable luber's new headset installment!
     
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