Technical FAQ
Photo: Dan Cavallari

Technical FAQ: chain wear, and chainring orientation

More discussion about measuring chain wear, and the correct way to align chainrings.

Have a question for Lennard? Please email us veloqna@comcast.net to be included in Technical FAQ.

Dear Lennard,
I subscribe to the magazine, and would like to compliment you on the exceptional article on the bike chain wear test. Great article on bike chain wear, that gave me new insight into my chain purchases. I have a few comments and questions.

Did all chains start at the same “length”? Many years ago, I bought a one of the first Wippermann stainless chains in an experiment to see if they really lasted substantially longer. Upon installing the chain, I tried to measure it with a Park CC-2 and couldn’t even get the pins to engage. Other brand-new chains would register a “0”. I ran that chain a long time before it would finally read. It didn’t seem to shift very well either, so I retired it long before it was worn out. Were the chains in the test all starting from the same “length”?

I take a lazy approach to cleaning chains both mountain and road. Our roads and trails are very dusty here in Idaho because we don’t see much rain. I remove the chains with quick links and put them in a one-quart sauce pan ($3.00 at a thrift store, don’t piss off your wife!) I add boiling water and add 3 table spoons of Simple Green. In 15 minutes come back and stir for 10-15 seconds. Wait for another 15 and stir some more then repeat. By the way do this in the garage or outside because aroma can bother some people. Then pour off the filthy water and sand particles and repeat. The third cycle is only boiling water to rinse. Virtually no scrubbing required, and the chain is really clean. The second batch of water/simple green can be used with a brush to clean chain rings and the cluster. Dry the chain with a soft rag and then hang to completely dry in the sun or other warm place.

In explaining this cleaning method, several people have commented that the boiling water could damage the plastic/nylon bushings or washers in the chain. This seems nuts to me. Have there ever been plastic components of any kind used in a chain?

When measuring chain stretch, I always put substantial tension on the chain via the pedal. Wouldn’t using this method obviate the need to buy a 3-point chain checker?

After installing a clean chain and riding for only 10 miles on clean pavement the residual oil has turned black regardless of the type of lubricant. Why? I am guessing it is from the aluminum chain rings and larger cogs.

Many brand-new chains come with a sticky persistent film that I hate. Some people recommend leaving it on. It is a dust and sand magnet. So, before I install one, I try to remove this “shipping coating” and then apply lubrication. Some of these coatings are very difficult to remove requiring nasty solvents.

Does flipping over the chain every time you clean it lead to longer life as some people advocate? Or does it actually shorten life? Zinn’s comments about not using a brand-new chain in racing would seem to require that both sides be broken in unless the mechanic is keeping track of the broken-in side.
— Russ

Dear Russ,
Lots of questions there.

Yes, all of the chains started at essentially the same length. At 12.7mm/link, 63 links measures 800.1mm, and all of them started within 1.2mm of that, or 0.15 percent. You can see from this 11-speed raw data & graph table, that at the initiation of the test, no chain was shorter than 800.1mm. With a 10kg load pulling them taut, the shortest chain was 800.3mm long, and the longest one was 801.3mm long.

Chain wear test: elongation (percent) vs time (hours).

There are no plastic components in a chain. I disassembled some chain links, and they are shown in the second photo here; all of the components are steel. Regarding concern about damaging the chain with your cleaning method, however, make sure you don’t soak a chain in Simple Green for more than a few minutes. As I discuss here, doing so can cause stress corrosion cracking and lead to sudden breakage of the chain while riding.

No, pulling tension on the chain does not “obviate the need to buy a 3-point chain checker.” You clearly have misunderstood the purpose of a 3-point chain checker; I recommend you re-read this article, in which I explain why that method is accurate and why measuring with a 2-point chain checker can lead to an incorrect conclusion. To accurately measure relative chain elongation, you can either put it under tension and measure your chain directly over a lot of links as we did here, or you can measure it with a chain checker on the rollers, as long as you measure from the leading side of one roller to the leading side of another roller further down the chain, which a 3-point chain checker does. By contrast, a standard, a 2-point chain checker measures from the leading side of one roller to the trailing side of another roller further down the chain; it pushes those two rollers away from each other and thus is measuring not only elongation of the links between those two rollers, but also the wear inside those two individual rollers. This leads to an inaccurate measurement, and the inaccuracy is compounded the fewer the links are that the gauge is encompassing. A longer 2-point chain gauge that encompasses more links minimizes this inaccuracy; it does not eliminate it.

The new chain turns black quickly due to rubber dust from car tires coming up from the road as well as to simply polishing the internal parts of the chain and removing a small amount of residue in the process.

With directional chains like the SRAM road 12-speed Flattop chain, flipping the chain over after cleaning is a moot point, because it won’t work flipped over. With a symmetrical chain, it could be argued that flipping the chain over after each cleaning could lead to longer chain life, as there would be a slight variation in the area of each collar bushing of each inner link that is taking the peak load from the inside of the roller. Periodically distributing this load to the diametrically opposed area of the collar bushing could increase the amount of time for the collar bushing’s outer diameter to decrease enough for the chain to reach one percent elongation and hence warrant replacement.

As for whether both sides would need to be broken in, I think that would make no difference. The chain runs more smoothly after the break-in period by polishing the internal bearing surfaces, and since the rollers still roll around all of the collar bushings, there would be no need to flip the chain. Furthermore, it is the exception rather than the rule that chains used in racing are removed for cleaning, so the break-in direction would be the lifetime running direction as well. My point was directed primarily at some pro teams that replace chains too frequently, sometimes to the point of replacing them daily in the Tour, as they are then running the chain primarily during the highest-friction part of its life.
― Lennard

Dear Lennard,
Are you aware of any rules governing the rotational orientation of the small chainring? I chose to align the tooth count etching with the big ring’s tooth count etching.
— Nick

Dear Nick,
First, place the chainring right-side out by having the logo and teeth number to the outside, just like you have it.

Secondly, the bump on the inner ring pointing radially inward goes behind the crankarm. Usually, that puts the teeth number and logo on opposite sides of the spider arm that is lined up with the crankarm, as you have it.
― Lennard


Lennard Zinn, our longtime technical writer, joined VeloNews in 1987. He is also a custom frame builder (www.zinncycles.com) and purveyor of non-custom huge bikes (bikeclydesdale.com), a former U.S. national team rider, co-author of “The Haywire Heart,” and author of many bicycle books including “Zinn and the Art of Road Bike Maintenance,” “DVD, as well as “Zinn and the Art of Triathlon Bikes” and “Zinn’s Cycling Primer: Maintenance Tips and Skill Building for Cyclists.”

He holds a bachelor’s in physics from Colorado College.

Follow @lennardzinn