Conference noted::bicycle

Mike,
    
    I'll need some clarification:
    
        Barnett's manual instead said to try this; put your chain on the
    big ring; pull it straight out at 3 o'clock - toward the front of the
    bike. If the chain moves at 6 or 12 o'clock, the chain or chainring is
    worn.
    
    What do you mean by, "if the chain moves"?  You mean if it will slide
    off the teeth at 12 or 6?
    
    r� 

    I'm confused too. I can understand the chain moving (slightly) if the
    chain *ring* is worn, because the worn teeth will allow the chain to be
    pulled round it. But if the chain itself is worn, then surely that
    would *redude* the movement at 12 and 6 o'clock, becuase the chain
    wear would soak up any tendency to move.

    The idea of pushing and pulling the chain on a straight edge sound a
    more accurate way of measuring wear. But for what length of chain are
    the stretch measures given (1/4" = 66% life left, etc.)?  The full
    length, or a fixed number of links? If it's the full length, then must
    assume that all chains are approximately the same length (not true!).

    -Les.

    re;.1
    	I am assuming that what they mean is that when you pull the chain
    forward at 3 o'clock, the chain shouldn't move at all at 6 or 12
    because the teeth are firmly seated in the valleys of the chainring.
    That would be the case if the ring and chain were in good condition.
    As the ring wears the valleys get longer and the teeth get shorter; as
    the chain wears the distance between pins gets longer. So if the chain
    can move forward at 6 or 12 then either the chain or the ring or both
    are worn to some degree. That's why you'd look at the chain next to see
    it it's the problem or if the chainring's the problem.
    
    Re; .2 It assumes a normal length chain. I'd guess that there's not a whole
    lot of difference between the lengths of a whole chain regardless of
    the bike. I'm sure that a bike with huge chainrings or long chainstays
    would have a longer chain, put probably only by a few links which 
    shouldn't make that much of a difference because you're really only
    looking at 1/8" to 1/2" wear differences.

Re.0

I would say that you have wasted a lot of money changing a cluster every time
that you change a chain. The cluster is much harder wearing than the chain and
the only thing that really wears them down is badly worn chain. If you change
your chain regularly (I do it every 6 months - a summer chain and a winter chain)
then your cluster should last years...

Graham.

     I agree with Graham... I change chains every year. The key is keeping
    the stuff clean and lubed for extended life.
    
      Chip

.3>  Re; .2 It assumes a normal length chain. I'd guess that there's not a whole
.3>  lot of difference between the lengths of a whole chain regardless of
.3>  the bike. 

    Recumbents excepted.  Mine's at least twice as long.  ;-)

    -Les.

    
    
    re:.4 and .5
    	I guess it depends on what you're riding. For a road bike, I'd
    agree with you. Changing the chain every 2000-3000 miles is probably
    adequate, but off road riding is considered abusive to the drivetrain
    and 300-500 miles is considered a normal lifespan for the chain. D.I.D.
    recommends changing the cluster when you change the chain, and for only
    $20 per cluster I'd say that the cleaner shifting and quieter
    drivetrain is worth it (to me that is- your milage may vary).
    
    Mike

Yeah, I was talking on-road. I keep forgetting that some nutters take their bikes
onto the muddy stuff... :*)

Graham.