Chain Maintenance & Keeping An Eye On Chain Wear

I thought about doing a repost of last year’s “Tandems & Spring Maintenance” entry, but decided to simply post a link to that and focus on chain maintenance instead.  So, here’s the linky to last year’s Tandem Maintenance Reminder.

Chain Maintenance

Keep on top of it!  Seriously, never forget that a drive chain is a consumable item analogous to the oil or spark plugs in the engines that power vehicles: it needs to be checked and replaced to make sure it’s doing it’s job without doing damage to other parts of the drive train.

Chains and the sprocket teeth they mesh with are all designed using a 1/2″ pitch and as the pins and rollers that connect the outer and inner plates of a chain wear down from friction the pitch increases between each pair of links. Most folks commonly call this chain stretch because, well… the chain truly does appear to get longer even thought the side plate lengths remain unchanged. However, if you let the chain pitch become too long the very expensive cassettes and chain rings that they interface with will start to become damaged.

If you’d like to dive into the esoteric aspects of chains, cogs, chain wear and lubricants you can find a wealth of information on-line at these two Websites:

If you’ve read through these two sites then you’ll now know something about chain wear measurement and measuring devices. Suffices to say, most of the chain checkers on the market only approximate chain wear, aside from the only one that most cycling science icons agree is accurate: the $70 Shimano TL-CN41 

Me, I use the Park Tools CC-2 Chain Checker, which only costs about $24 because that’s just what I happened to buy about 10 years ago; it was and still is “good enough” for easily monitoring chain wear.  However, I supplement the use of my CC-2 with a steel rule when making the final decision on when to chuck a chain.

Case in point, after last weekend’s ride I was reminded that our drive chain was in need of lubrication as the tell-tale sound of squeaky links was very obvious on some of the steeper climbs.  So, after getting home I put the Calfee in the work stand and prepared to remove the chain so I could give it a bath in solvent and then throw it in the Fry Daddy for a nice hot paraffin wax bath.  But, before going to all that trouble I thought I’d do well to check the chain for wear, as it had about 2,200 miles of use since being installed.

Again, I don’t have the highly accurate Shimano TL-CN41 in my tool box but have always gotten predictably easy to interpret results from my well-worn Park Tool CC-2 Chain Checker.  The ‘trick’ to using these lesser chain checking tools is understanding that they are actually telling you as well as baselining their calibration markings to the chains on which you use them.

In regard to the CC-2, it’s not all that unusual for a new chain to show somewhere around 15% “wear” right out of the box. When the thing starts to read in the 75% wear range it’s about time to change the chain.  I try not to let my chain’s “stretch” to the point where my CC-2 reads 100% wear, as by that point the expensive stuff has been damaged: really.

These are photos of both the “old” chain (above ruler) and new chain (below), noting I actually let my chain wear a little longer than I like, almost to 3/32″.  You can see what that looks like with my CC-2, i.e., about 80%. And then the third image is a representation of just how much longer the old chain showing 3/32″ of wear is vs. a brand new chain hanging side by side.

  

Again, I always go back to the ruler for passing final judgement since it continues to about as reliable as anything else, short of the $70 Shimano tool. In terms of how to use a ruler to check chain wear and how to interpret the results, let me just quote from the linked information at Sheldon Brown’s site:

Measuring Chain Wear

The standard way to measure chain wear is with a ruler or steel tape measure. This can be done withoutremoving the chain from the bicycle. The normal technique is to measure a one-foot length, placing an inch mark of the ruler at the side of one rivet, then looking at the corresponding rivet 12 complete links away. On a new, unworn chain, this rivet will also line up exactly with an inch mark. With a worn chain, the rivet will be past the inch mark. [For accurate measurement, the chain should be held under some tension — either on the bicycle, or hanging vertically. — John Allen]

This gives a direct measurement of the wear to the chain, and an indirect measurement of the wear to the sprockets. In English measurement:

  • If the rivet is less than 1/16″ past the mark, all is well.
  • If the rivet is 1/16″ past the mark, you should replace the chain, but the sprockets are probably undamaged.
  • If the rivet is 1/8″ past the mark, you have left it too long, and the sprockets (at least the favorite ones) will be too badly worn. If you replace a chain at the 1/8″ point, without replacing the sprockets, it may run OK and not skip, but the worn sprockets will cause the new chain to wear much faster than it should, until it catches up with the wear state of the sprockets.
  • If the rivet is past the 1/8″ mark, a new chain will almost certainly skip on the worn sprockets, especially the smaller ones.

Of course, now that it’s time to break out a fresh chain I must once again wrestle with the choice of lubrication.  I’ve been using ProLink Gold (aka, ProGold) on the timing chain for the past 6 months and have been really impressed with it.  It’s not as clean as my beloved hot melt paraffin lubrication mix but with regular chain wipe downs using a terry cloth towel after every other ride it does keep the chain nicely lubed without becoming a grunge magnet.  However, if you put your hands on the chain it’s definitely going to leave you with a greasy mess, something wax doesn’t do.

So, as for right now, the Calfee is hanging it the garage without a chain as I mull over using the ProLink Gold on this new chain to see if it will deliver longer chain life at the cost of having to deal with a greasy chain.

Of course, with a current wind chill of 15°F there’s no hurry to make that decision today.

Advertisements

About TG

I've been around a bit and done a few things, have a couple kids and a few grandkids. I tend to be curmudgeonly, matter-of-fact and not predisposed to self-serving chit-chat. Thankfully, my wife's as nice as can be otherwise we'd have no friends. My interests are somewhat eclectic, but whose aren't?
This entry was posted in Technology & Equip.. Bookmark the permalink.

7 Responses to Chain Maintenance & Keeping An Eye On Chain Wear

  1. Ken says:

    Thanks for a great informative article.

  2. Chris says:

    Many longtime pro mechanics will slap on a new chain right out of the package with original grease on it and let it go at that. For me, I’ll always remove the grease in a solvent bath and thoroughly dry it with compressed air before applying the lube of my choice. Mark, I’m sure you do this before dipping your new chain into the hot melt wax bath. Did I miss that in your blog?

    I started waxing my chains in the late 1970’s and tried many variations on the theme, including mixing in powdered graphite and later powdered teflon, and always got great life from my chains. I don’t know how effective my additives were, but I once toured all Summer (1980, nary any rain in the Western U.S.) on a graphite+waxed chain that lasted 3500 miles without appreciable wear. Rewaxed on the road after the first 1500 mi.over my Optimus stove.

    Today i use any of several synthetic light oils, and usually swap out a used chain after 1500-2000 mi. of dry weather riding. Waxing is more labor intensive and chains just aren’t that expensive, since I’m not of the Campagnolo faith. Timing chains on the tandem last many, many more miles, they seem more durable or maybe less stressed, though I have no explanation for that. Same brand of chain, same chain lube and lube schedule.

    Finally, I’ve been well pleased with the ProLink chain guage, accurate and trusty. $19.99, it’s on the Pardo.Net link in the blog.

    • TG says:

      I didn’t go into the details of how I go about cleaning and lubricating chains in this posting.

      Suffices to say, you can either stick with the factory lubricants which are actually quite good and will typically last the life of the chain so long as you don’t mind the gunk that collects on the chain, cassette and drive rings, or…. you can use a solvent to strip away all of that factory grease before reapplying some other type of lubricant. Doing anything less than that simply contaminates your new lubricant and inhibits the properties that made it attractive in the first place. Same thing goes for changing lubricants on an existing chain: you must strip and clean the chain before you apply the new lubricants.

  3. Chris says:

    Yup.

    Now, as you “…mull over using the ProLink Gold on this new chain to see if it will deliver longer chain life at the cost of having to deal with a greasy chain.” , I’d like to suggest that you go ahead and try the PL Gold and blog later re: how you rate it. I’d be interested to know the tandem stoker’s opinion on the greasy chain too, and whether you think a waxed chain is easier to deal with when packing the bike for travel.

  4. Steve says:

    I use a Park Tools CC-2 Chain Checker also and I have a question about how to use it: I set it to 0%, put it on the chain and rotate the lever until it’s tight. When I do this, the pins on the gauge end up on opposite sides of the chain; in other words, it’s reading diagonally across the chain. Is the checker calibrated for this, or are you supposed to try to hold the checker so that the pins are on the same side of the chain? Does it matter?

    • TG says:

      It’s all measured from one side of the chain, and between a leading and trailing pin as shown in this Park Tools’ video:

      OR, if you prefer, use this drawing as a reference:

      Park CC-2

  5. Pingback: Chain Lube Du Jour: Pro Link Gold « The TandemGeek's Blog

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s