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Chain replacement question...(7 posts)

Chain replacement question...03Vortex
Sep 2, 2003 10:07 AM
I have approximately 3,000 miles on what is a new bike meaning new chain and cassette. My symptom is a consistent ticking noise coming from ONLY the 5th cog (no others) whether in the big or small chain ring most noticeable while applying some pressure to the pedals. My LBS (where I bought the bike) tells me my chain is stretched and may need a new cog. This is all Dura Ace. Is 3,000 miles resonable amount of mileage to expect to have to replace all of this??
re: Chain replacement question...TJeanloz
Sep 2, 2003 10:10 AM
The 5th and 6th Dura-Ace cogs (depending on the ratios) are often pinned together. Try removing the cassette and dropping a drop of Tri-flow (or similar lubricant), on each of these rivets. This is a somewhat common problem.
Sep 2, 2003 10:13 AM
Replacing a chain after 3000 miles is perfectly reasonable, and possibly a bit late. Replacing only the cog, as opposed to the whole cassette, is a commendable attempt by your LBS to save you some money.

Replace chains early and you won't need to replace cassettes - at least for a long time.
Change chain first and test, cassette might be okay. nmSpunout
Sep 2, 2003 10:31 AM
For Acera, 2000 would be enough ...Humma Hah
Sep 2, 2003 11:11 AM
2000 miles on a Shimano Acera corncob and original chain was enough to trash both. The new chain tended to "inchworm" on the 5th cog on the original 7-speed freewheel (the one I used the most).

I was appalled. I'm used to getting tens of thousands of miles on Schwinn singlespeed cogs.
measure chain first to see if it's stretched.Spoiler
Sep 2, 2003 2:05 PM
There's no reason for a Dura Ace cassette and chain to be worn or stretched enough to cause a ticking. Measure the chain to see if it's stretched.

1. Measure a one foot section of your chain. Set one end of a ruler/tape measure on a rivet edge, and measure to the rivet edge 12 inches further along the chain.
The distance between these rivets should be 12 inches exactly. If it's 12 1/8, it's stretched far enough to cause problems. If it's only a bit over, like 12 1/16, you might want to replace the chain.

3k miles out of a chain and cassette is unacceptable. Unless you never oil your chain, and you do intervals on sand dunes, your chain should last longer and your cassette should last much longer. A Dura Ace cassette should last at least twice as long.

I don't see how a stretched chain would cause problems on only one particular cog.

There's a possibility that the particular cog has a problem with it's teeth. Maybe it got hit by something.
I'd believe itfiltersweep
Sep 2, 2003 3:35 PM
I "only" had 3500-4000 miles on my last DA chain... I'm always swapping cassettes, so I have no idea about that dept. My only symptom was "autoshifting"- and this was not a neglected drive train. Prior to that, I was always able to "re-set" the cassette if I ever had any shifting problems in some gears and not others, since there is a bit of play on some hubs (some wheels more than others).

Frankly, IMHO, it is better to err on the side of caution with a cheap fix like a CHAIN rather than chewing up a newer cassette. As for the general advice to replace chains and cassettes together because they wear together- I think it is a bunch of hooey!