Bicycle Mechanics - should I replace chain now?

I have about 9000 miles on my bike and the only things I have replaced are tires, tubes and bar tape.
The question is, should I replace my chain now? I clean it very often with the rolling scrubber type chain cleaner and water soluable degreasers and keep it well oiled. I have been checking it via the 12 inches from pin to pin method and the chain only shows about 1/32" of "stretch". The shifting and smoothness seem the same as always, no troubles at all. I have inspected the cassette for wear and only see very little difference on the cog I seem to ride in a lot. I noticed that not all the teeth on the cogs are shaped the same, I suppose that helps with the shifting?
I know the general consensus is like 2-3000 miles for replacement, but given my experience with this bike it doesn't seem necessary.
The group on this bike is Shimano Ultegra with 9 speed cassette.
What does a chain and cassette usually cost to replace?

Some riders get up to 12,000 miles on a chain.

Depends a lot on what you replace them with and where you get the stuff. Ultegra components will run about $40 for the chain and maybe $75 for a cassette on eBay. The prices have moved over the last years so your mileage may vary.

So long as you're measuring stretch accurately, you're marginal for a chain replacement. I'd lean toward replacing the chain and leaving the cassette alone. Or you could ride another year (or 1/32" stretch - or more) and replace the two together.

There's two schools of thought on this issue. One says that riding the chain and cassette into the ground is more cost effective in the long run and I can see the point. But I still prefer to keep within conventional wear limits - especially if you ever want to change your rear gearing without making it a major repair job.

I would keep using it until you have to replace both. With 9K miles now, and more to go, you will be getting top mileage from both components. bk

9 Sp chains with a master link start at $15.00
Cassettes start at $25.00

I replace my chain about every 1800 miles. Then I replace the cassette every 4th time I change my chain. That may sound like over kill to some but I find that I get better performance at less cost. With a chain that has 9000 miles on it the cassette will need ot be replaced and possibly the chain rings.

IM looking to change mine along with cassette in another 1000 or so. (currently have around 3k)

you could get one of those chain checking tools for a few bucks. I bought one and checked all my bikes yesterday.

http://www.nashbar.com/bikes/Product_10053_10052_124596_-1___

9 Sp chains with a master link start at $15.00
Cassettes start at $25.00

And bicycles start at $39.95.

And bicycles start at $39.95.

Naw. Bicycles start at $15.00

Plan on a new cassette too. The most used cogs will have worn with the chain and won't mesh properly with a new chain even if they look perfect.

I dunno. 1/32" stretch isn't a lot. I bet the cassette would accept a new chain without complaining too much.


Btw, I didn't mention it but you don't have to stick with Ultegra. A 105 or Tiagra cassette would work fine if you can get a better price. Personally I don't like to scrimp on chains but they've gone up so much lately I may have to.

And I've had very good luck buying *used* components off eBay. Even used cassettes from people who change gearing or like to change cassette and chain at small intervals and re-sell. YMMV, though.

yeah don't guess, just get a chain gauge tool, they are only about $4,, as far as the cassette dont guess on that either, inspect it it for worn down, or broken teeth, twist it around in your hand to make sure it is not ready to fall apart

Measuring isn't "guessing".

I find that 'chain gauges' are less accurate than a 12" steel rule, properly applied.

Besides, that isn't the question. It was whether 1/32" stretch is enough to dictate a component change.

If you replace the chain regularly, before the wear limit, the cassette will last a long time. I have gone through at least five chains on my cassette and it still shifts perfectly.

As others have said, the other method is to simply ride the same chain and cassette forever, and it will be forever, probably five years or more, but you will never be able to use a different cassette on the bike.

My preference is just to replace the chain with a cheap one, a KMC chain goes for between 15 and $19, and always have a drivetrain that is within specifications so that I can have more than one set of wheels, or have the option of using someone else's wheel.

My take is that chains are cheap and disposable, so if you're wondering if you should change it, why not just throw down the $30 so you don't have to worry about it?

I've always got to mention that chain checking tools are nearly worthless, since they combine roller wear and elongation into one meaningless reading, plus they show some new chains to be .25% elongated when new. That false wear must be subtracted from future readings.

My bet is that regardless of the amount of elongation, installing a new chain now may result in chain skip on one or more cogs and the need for a new cassette. The rollers and cogs still get worn together and the old cogs may not mesh with a new chain at this point.

9,000 miles with only 1/32" of stretch over one foot woould be highly unusual for a Shimano chain. I'ved lubed a DA chain after nearly every ride and only got about 4,000 miles for 1/16" elongation.

The most accurate way to check elongation is to use a machinist's scale. Lay one end on the edge of a pin and then check the pin exposure at the other end. When nearly half a pin is exposed, you've reach 1/16" elongation.

Then I've got to add that the scale check for elongation is not always a proper check of wear. A Campy chain may show 1/4 the elongation of Shimano chain with equal mileage, but doesn't last four times as long. It may last 50% longer (like 6,000 miles instead of 4,000), but roller wear usually dictates the life, not elongation.

Well, there have been some great points and discussions made on this topic.
In the end I have decided to replace both the chain and cassette. I looked real close with a lens at the cogs (I am over 50!) and could see where gear #4 has slight visible wear and deformation.
The chain really doesn't show any more stretch than the width of the mushroomed part of a rivet.
So, I decided to change gearing from 11-23 to 11-21 and gain a useful cog with 16 teeth.
I am just thankful I could get 9000 miles out of this chain and cassette without a hint of trouble. It is apparently a little beyond ordinary.

Well, there have been some great points and discussions made on this topic.
In the end I have decided to replace both the chain and cassette. I looked real close with a lens at the cogs (I am over 50!) and could see where gear #4 has slight visible wear and deformation.
The chain really doesn't show any more stretch than the width of the mushroomed part of a rivet.
So, I decided to change gearing from 11-23 to 11-21 and gain a useful cog with 16 teeth.
I am just thankful I could get 9000 miles out of this chain and cassette without a hint of trouble. It is apparently a little beyond ordinary.

The best way to tell if a cassette really needs replacing is to install the new chain, then check for chain skip when pedaling with a high torque and low cadence (like standing while pedaling uphill). Chain skip is really obvious. I avoid chain skip by alternating the use of several chains.

Since I use 3 different sets of wheels with different cassettes on a bike, I realy want to preserve these cassettes, so I change the chain often, probably too often But I have friends that just do not change anything until they have to change the chain and cassette.

I avoid chain skip by alternating the use of several chains.

Seriously? You have more than one chain and you rotate them in and out?