How To Use A Bike Chain Tool

Your bicycle's concatenation is put through hell every fourth dimension y'all ride. For every minute of pedaling, approximately 44,000 chain pieces are in move, creating 320,000 divide instances of sliding surface friction. And all of this is on a component that sits near to the ground and is exposed to the elements.

Just like your tyres and brake pads, bondage habiliment with use. And every bit a chain wears, friction in the drivetrain increases, your shifting gets sloppier, and worst of all, you'll quickly outset wearing out other drivetrain components. Changing your concatenation at the correct fourth dimension tin can salvage y'all coin and brand your riding more enjoyable.

If you're seeking a quick respond for the easy way to bank check for concatenation wear, you should merely need to read the outset few sections of this article. If you want to go deep down the rabbit hole, well, we can assistance you with that as well.

Basics of chain wear explained

Over time, the chain'south pins and inner links will wearable, and every bit a result, the pitch (length) of each link will grow. Because the chain's overall length grows with vesture, chain clothing is normally called 'chain stretch' – fifty-fifty though the metal does not (measurably) stretch.

An exploded view of a single chain link.

The standard pitch of a new chain link should sit at half an inch (12.7mm), pin-to-pivot. An inner plus an outer (wide and narrow) link of a chain makes an even inch. Chainrings and cassette cogs are designed with this pitch in heed, such that the chain rides at the base of the cog/band when new. Equally the chain pitch grows, it rolls higher on the tooth, accelerating cog wear until eventually it just skips over the top. And it's this dreaded chain skip that y'all never desire to feel when you've got all your weight loaded on a pedal.

Once the chain wears, the cassette and chainrings start to wear along with it, becoming 'hooked' from the loftier-riding chain. Replacing your chain before it wears too badly will dramatically increase the life of the rest of your drivetrain (cassette and chainrings). A $forty chain every few months could save you hundreds past preserving your drivetrain.

When to replace a chain

There is no verbal science to knowing when to supercede a chain. And there's likewise plenty of debate about what classifies every bit a worn chain. However, the information in this article should get you as close to the reply as is known.

It'due south common to hear distance recommendations for how frequently you should replace your chain. Only as we covered in our Holy Grail of chain lube commodity, there are only too many variables for this to be a reliable technique – and in reality, a simple difference of chain lube and maintenance tin result in a longevity divergence of anywhere between 500km to fifteen,000km. This is why you demand to manually bank check it.

How long a chain will concluding volition depend on your riding strength, your selection of chain lube, the chain, riding weather condition, shifting habits and the terrain you ride.

Fifty-fifty when cost isn't a factor, the likes of the top WorldTour teams regularly supplant chains approximately every ane,000km (a calendar week in a M Tour). Some mechanics claim they get up to 3 full seasons out of cassettes and chainrings this style, just more importantly, in that location's far less risk of a broken chain in the oestrus of the moment and it's more efficient, besides. Additionally, a worn chain will exhibit greater slack that leads to slower and sloppier shifting.

Whether you want to run your drivetrain into the basis is your call, but the trend toward more expensive cassettes and chainrings is clear.

This argument for regular concatenation replacement is rather clear-cut if you're riding on Shimano Dura-Ace, Campagnolo Super Record and SRAM Ruddy components where the cogs can cost as much as an entry-level wheel. However, the value suggestion becomes a tougher contend if you ride on 105 or beneath where replacement chainrings and cassettes are far more than affordable.

Additionally, you'll need to consider the installation cost of a new concatenation if you're not confident in doing it yourself. Or the cost of a chain breaker if it's a job you're looking to have on. Nevertheless, if y'all value crisp shifting, an efficient drivetrain, or if yous often swap between wheelsets, and then regularly replacing chains before they develop significant wear is a smart choice regardless of what your components cost.

For that, you should do a transmission check (see next section) for article of clothing on a regular basis. If you lot're a casual road passenger, I'd suggest checking every couple of months, and if you ride most days of the calendar week, so you should check it at more regular intervals again. The slacker you are with bones chain maintenance, the more y'all should proceed a check on wear. And be sure to increase your checking intervals during the muck of wintertime, too. With time you'll go an understanding of how long things concluding, and when you should be watching for wear.

If you ride mountain bikes, gravel or cyclocross, then beware that your chain replacement intervals will probable be far more regular again. Information technology's not uncommon to hear of riders wearing through a chain in a single poor-conditions endurance consequence.

Measuring chain wear the free and piece of cake way

And then how about measuring that concatenation habiliment? Well, the easiest (and free) way is equally follows:

1. Shift gears so that your chain is in the big ring and smallest gear on the cassette (eastward.g. 53-11T)
ii. Pull the concatenation at the forepart of the chainring as shown. If the chain starts to elevator off the top and/or the bottom of where it sits on the chainring teeth, this ways that the chain is starting to wear or is worn.

If your chain lifts off the ring like this, information technology'due south likely worn.

This 'lift' is possible considering the chain'due south pitch has lengthened and so no longer sits properly in the teeth. The photo below shows a brand new chain. Chances are if your chain lifts off more than our worn case, you'll exist needing more than than a new chain. Yet, exercise beware that worn chainrings can requite a fake reading with this method, and a new chain on a worn-out chainring will present similar lifting.

Every bit pictured, a new concatenation will inappreciably lift from the ring.

However, while this method is complimentary, it doesn't provide much indication for how worn that chain is, or whether you lot've worn the concatenation so far that your existing cogs won't accept a fresh chain. That'southward where tools come in.

The easy tool method

So how worn is your chain? Is information technology so far cooked you lot'll need a new cassette? Or is it simply an old chainring telling y'all lies with the previous method? You'll need a tool to know for sure.

At that place is the ruler method which I encompass later, merely my suggestion is to utilize an affordable, purpose-built chain checker tool. The unproblematic stock-still-length, drop-in style tool is all y'all need and will chop-chop requite you a become or no-become judge on your concatenation wear.

Uneven chain wear — This digital chain clothing checker proves that chains don't wear evenly across their whole length. Additionally, dirt and grease (as seen here) can profoundly affect the measurement.

It's important to know that chains rarely wear evenly across their entire length. And so withal yous choose to measure your concatenation clothing, y'all should practice information technology across three to v separate sections and utilise the highest measurement. And avoid including the quick link or like joining link in your measurement as these often accept slower wear rates.

Using the popular Park Tool CC-three.2 concatenation wearable checker every bit an instance, the .5% marking is there as a recommended replacement point for xi and 12-speed drivetrains, or as a warning for those on 10-speed or lower setups. The .75% reading is the suggested replacement point for ten-speed and lower. Some tools offer a 1% wearable point, too, something best kept for viii-speed chains or lower.

The Park Tool CC-3.2 offers both .v% and .75% habiliment indications.

This .5% suggested replacement indicate is fairly new and comes from an increased agreement of how the narrower cogs of modernistic drivetrains offer less surface area, and are therefore more than prone to textile wear. Because of this, many older chain vesture checkers on the markets are outdated, and will but show chain wear on newer drivetrains at a point that'southward also late.

If a concatenation is worn, the tool volition drop into the link and sit affluent forth the chain. Or if it's non worn, the tool will sit in a higher place the link, every bit shown in the atomic number 82 photograph. For our own bikes running the good stuff, nosotros'll replace a chain at the .five marking. This applies to our x, 11 and 12-speed setups.

Still, at that place are important exceptions to this. If you just wanted the simple answers, y'all tin can cease hither. I do, nonetheless, recommend reading some related chain articles.

If y'all want the deep dive, and so stick with me — this will get a little geeky.

A deeper dive into the mechanics of chain wear

During each articulation around a chainring, cassette or pulley wheel, the eight pieces that make a total chain link are experiencing an enormous amount of friction. It'southward like shooting fish in a barrel to meet how and why concatenation lubrication tin play such an important role in efficiency and durability.

With each articulation, the riveted pivot remains static, with the aforementioned surface repeatedly seeing friction. Similarly, the roller is held static when in contact with a cog – it doesn't roll. As a upshot, it's the inner link plates that are articulating around the static pin.

As the inner plates articulate around the pivot, the pin is worn thinner, and the inside bores of the inner links aggrandize. This wearable leads to play between the pieces, and when the chain is pulled under tension, its length grows. This is elongation vesture (aka, stretch).

It'south the altitude from roller to roller that the cogs actually experience.

Traditionally the general goal of chain-wear-checking is to measure out this elongation, excluding the rollers surrounding the pivot and inner links. Notwithstanding, the cog and chainring are dumb to this measurement, and really, information technology'southward the altitude between the compressed rollers that the cogs witness. And just as the pin and inner links wear together, so likewise can the inside of the roller and the exterior diameter of the inner links. I'll come dorsum to this.

Wearing of the inner and outer plates, known every bit lateral wear, is as well a key cistron to consider. This will see the side-to-side play in your chain increase, and with it, you lot'll experience slower shifting as the derailleurs and shifting ramps work harder to pull the floppier concatenation onto the desired cog. It won't lead to the wear of other components, but it will terminate your shifting from working at its best.

A deeper dive in to chain tools

At present dorsum to concatenation wearable tools.

A tool like the Park Tool CC-3.2 is attempting to measure the altitude from one pin to another, however, as it sits confronting the front of i roller and the backside of some other, its reading can be thrown off by the rollers. This shouldn't exist an event, only non all rollers are created equal, and it's common to detect some chains that have rollers that are looser-plumbing fixtures, faster-wearing or simply different diameters than others.

Because of this, some chain wear checkers seek to isolate the roller habiliment from the measurement and do this by measuring from equal, and non opposing, sides of the rollers. Examples of this include chain tools from Shimano, Pedro's, and more recently, Park Tool (CC-4). They should provide a more than consistent reading across a greater variety of chains, even if they're all the same impacted past roller wear and roller variances (just to a far lesser caste).

Most chain wear indicator tools, such equally the Park Tool CC-three.2 drawn at the top, measure out from opposing roller faces. While others seek to isolate the roller diameter from the equation by measuring behind-to-backside.

"The three-point measurement system used on the Pedro's Concatenation Checker Plus Ii accomplishes this by pushing both rollers in the same direction during measurement, instead of in opposite directions, equally is the case with common two-bespeak measurement tools," explains Jay Seither, Pedro's head of product management and engineering. "As a consequence, the Chain Checker Plus achieves a true mensurate of the pin-to-pin altitude."

For the best concatenation article, Adam Kerin of Zilch Friction Cycling measured, on boilerplate, 19% earlier wear rates by using a two-bespeak digital concatenation checker than when measuring the external pin-to-pin elongation of the chain (I'll soon explicate how to mensurate information technology).

The reasons for this discrepancy are down to roller tolerances and roller habiliment. The fact that some chains offset life with looser rollers than others is not news. All the same, in what'south arguably new information to everyone in the drivetrain space, Kerin found that some chains had rollers article of clothing at a far higher rate in proportion to the pins and inner links. And as mentioned before, the cog's teeth don't care about these discrepancies, rather it's merely the distance between the rollers under load that really matters.

Park Tool'southward Projection Manager, John Krawczyk, concurs with this. "Whether a chain measures only 0.001% wear or 0.75% "worn" when it is new, this doesn't alter the fact that the cassette and chainrings don't care how new or how erstwhile the chain is," he said. "All they know is that once the chain goes beyond 0.75% wear (or whatever the replacement metric from the concatenation manufacturer might be) those rollers no longer fall cleanly in the valley between the teeth and either the concatenation needs to exist replaced or the teeth begin to be re-shaped."

Given this, and despite such glaring measurement discrepancies, both Kerin and I are of the stance that the drop-in mode concatenation checker tools are still the best and easiest way to keep a check on wear, and that it's best to change a concatenation that becoming worn than one that'southward overdue.

For various reasons, I'grand not a fan of the tools pictured. They're either too easily damaged, or provide wear notification at a point, that in my opinion, is also late.

When shopping for a chain wear checker, look for ane that can't be damaged through misuse (which will so cause premature wearable readings), and one that offers staggered wear readings to give you a rough indication as to the indicate of wear. Avoid tools that only offer a unmarried signal of vesture measurement – they'll only tell you when your chain is toasted, a point that'south too late in my opinion.

I've long been partial to the Park Tool CC-iii.two every bit a budget pick, and in most cases, I continue to find it a reliable choice. There are enough of similar choices sold by others, but experience shows that the cheapest ones tin can exist a little hitting-and-miss.

KMC Digital chain wear gauge — The KMC Digital Chain Vesture Checker is a personal favourite every bit it allows like shooting fish in a barrel and finite article of clothing measurement. However, practise beware that information technology is influenced by concatenation roller diameter.

For more finite clothing-checking, my preference is the KMC Digital Chain Wear Checker. It's priced high and is certainly overkill for most, but it lets me monitor concatenation wear in tiny increments. I'll replace chains once they tip over .4mm on this tool, which is a hair sooner than the .v% measure on the CC-3.ii.

SRAM chains are one articulate exception to using these suggested tools. Most chains on the market start with a roller that's 7.63-7.65mm in outside diameter. SRAM'south chains are larger — for example, rollers from a Red 22 chain are 7.69-seven.70mm, while an Hawkeye 12-speed chain uses rollers that measure 7.72mm. And SRAM'southward new Flat-Top chain as office of the Route AXS groups is larger again (7.90mm).

SRAM chains, and their oversized rollers, throw a spanner in the works. If you're dealing with SRAM chains, then definitely go yourself a tool like the Pedro's Chain Article of clothing Checker Two or Park Tool CC-iv. They'll work great with all other chains, besides.

Of form, that throws off any tool that measures from opposing sides of the rollers. This is where Pedros' Chain Checker Plus II, or Park Tool's CC-4 come up in. These backside-to-backside chain checkers will work beyond all chains, including SRAM.

Considering of this, both Pedro'south Chain Habiliment Checker Two and Park Tool'south CC-4 are fast becoming my preferred options, and for not a large increment in price. The Pedro'southward manages to combine other tools into it, while the Park feels a little more than rigid in use.

Alternatively, yous can apply a vernier caliper to measure (and tape) the altitude between 10 links when the chain is new so monitor it for .five% clothing from there. Employ the calipers inside the rollers, just every bit if information technology were a chain wear tool. The use of a vernier caliper is what Campagnolo recommends, nonetheless, it is a more involved method that involves a potentially more than expensive tool (merely is useful for more than than but chain wear checking).

Regardless of what tool you lot use, it's a good thought to learn how it measures on a new chain. If a tool reveals worrisome clothing on a new and decent quality chain, then information technology'south perhaps non a tool to trust.

chainwear tools — Tools, tools, tools. There are many chain wear indicator tools on the market.

Tools, tools, tools. There are many chain wear indicator tools on the market.

Using the tools

The corporeality of tension practical to the chain, and how dirty it is, will affect the reading with any tool used. A dirty chain will probable always read every bit being less worn than what information technology actually is, likewise for a concatenation doused in a thick lubricant. While the more tension you put on the concatenation, the more worn it'll read. And this is where things tin get tricky.

Tools such every bit the Pedros' Concatenation Wear Checker Plus 2 and Park Tool CC-4 permit y'all to apply some chain tension in the procedure of using the tool.

Chains are never ridden without tension. Given that, Jason Smith, CeramicSpeed's Principal Engineering science Officer and the person responsible for much of the newer understanding of concatenation wear, recommends measuring your concatenation while it's under load. After all, that'due south how it interfaces with a cog in use. Pedro's Chain Checker and Park Tool's CC-iv allow you to use a load directly in using the tool (although it is non across the full measuring bridge), while with other options you will need to create the load separately.

Here's my technique. With the rear wheel held in place (easiest if it'southward on the ground), I pull on the creepo until any easily discernible slack in the concatenation is taken up. With the concatenation clothing tool in the top-span of the chain (above the chainstay), I then check whether the tool drops into its wear mark. It's far from scientific, but it'due south quick and relatively repeatable.

Nearly tools volition simply drib into place if the concatenation is worn, and so only ever apply a lite load to the tool, and never force it. If yous're having to push down on the tool with any level of effort, the concatenation is non worn.

This communication is something that Krawczyk of Park Tool reiterates. "Chain and tool tension can greatly touch on the effectiveness of any concatenation wear indicator," he says. "Every bit wise mechanics say, 'No matter how good the tool is it is only as expert equally the mechanic using it.' With that said we do find that by measuring roller back to roller back (like on the CC-4) this does help minimize the dependence of a set tension. [Nevertheless] if you push hard enough the tool tin and will flex, effectively forcing the tool into an otherwise new or non-yet-worn chain."

Information technology doesn't make a whole lot of sense to clean a concatenation prior to replacing information technology, simply just know that the grittier, greasier and grosser your chain looks, the likelier it's more than worn than what the tool tells.

And call back my earlier point regarding uneven chain article of clothing? Be sure to measure multiple spots along the chain'due south length, and use the highest measure.

Chain vesture is not linear

When keeping a check on concatenation vesture, information technology'southward critical to know that the wear does not happen in a linear way. If you lot get 3,000km of riding to .25% wearable, you'll unlikely go another 3,000km past the time the chain reaches .5% wear. This is considering most quality chains have a number of surface hardening treatments and low friction coatings which will wear away with use – accelerating fabric wear. Additionally, the contamination inside the chain's links volition increment with employ.

Don't get caught out. Be sure to check at regular fourth dimension-based intervals, and don't rely on distance as a measure.

Measuring the chain elongation

It's often recommended that the virtually accurate and best manner to measure your concatenation is with a ruler. The theory is that by measuring pin-to-pin yous can accurately guess how much clothing has occurred in the components of the chain and it removes any question over roller tolerances and wear, instead focusing solely on the actual pitch of the chain.

However, in my opinion, this procedure is fraught with the likelihood of user-mistake. Lining upwardly a ruler from the centre of one pin to another 10 or 12 links away, all while remaining within less than half a millimetre of accuracy, isn't something that many can do consistently. Additionally, you won't be able to hands add tension to that chain, and then clay and lube volition have a huge touch on the measurement.

If you lot disagree (yous're wrong!), then the procedure is as follows:

With your chain yet on the wheel, place a ruler's cipher inch mark directly above the center of one of your chain pins. At present count 12 complete links. A complete link equals one inner and i outer. A rivet on a new chain should line up exactly to 12 inches (304.8mm) on the ruler.

Using a ruler is the sometime tried-and-trued method. However, I'grand non a fan of the method when you consider before (shorter) replacement points, chain tension and general homo error.

As a general rule for ix-speed or lower drivetrains, if the rivet is less than 1/xvi″ (one.59mm) by the marking, your chain is ok. If information technology's betwixt 1/16″ and 1/8″ (3.18mm) past the mark you'll likely need a new chain, but your sprockets should exist ok. If it'south more than than 1/viii″ past the mark, you'll probably take to replace both the chain and cassette. For ten, 11 and 12-speed, you'll want to supercede the chain as shortly as it reaches ane/sixteen", or in other words, .5%.

Every bit mentioned, I don't rate the ruler method. The post-obit, more than-involved method produces more accurate results but involves tracking chain wear over the entire length of the chain, starting from when information technology'southward brand new. This is because while all bondage should measure an inch per a whole link, it's rarely the case. Jason Smith previously found a difference in elongation between unused chains of the same brand. There are certainly variances!

For this, one time the new chain has been cut to the correct length, hang it off a blast or similar hanging space that'll remain consequent. Measure the total length of the new concatenation, from the eye of one terminate to the centre of the other end. If it'due south an option, you lot can mark on the wall (employ tape) where the concatenation reaches.

Arrow direction of master link — Measuring for wear off the bike should merely exist done if your concatenation has a quick link, and even then, it'due south of import to consider if you want to undo them.

From here on, yous'll demand to measure out your chain wear with the concatenation off the cycle, and replace information technology when the total length has grown by .five% from the original. This is only suggested for chains using a quick link, and you'll demand to practice the measurement after the chain has been cleaned and with a weight pulling downward on it (Smith suggests a 50lb / 22kg weight at most).

And merely when you're thinking this all sounds similar too much piece of work, too recollect that chains don't vesture evenly, so it's quite possible that at that place are sections of the concatenation that are far more than worn than what the total length measurement suggests.

Aye, chain wear checker tools aren't perfect, only they're better than the alternative!

Worn chainrings and cassette

Think those .5% and .75% suggested replacement points? Well, unfortunately, chain elongation is not the simply cause of cog wear — pure metal-on-metal abrasion is a major cause, too.

Myself and countless others accept experienced it where a chain may only be slightly worn, merely due to a poor choice of lube and a lack of basic maintenance the concatenation has abraded through a cassette. At that place is enough of truth to the old saying that a clean bike is a happy one.

In Kerin's chain lube testing, he discovered huge differences in cog vesture equally the direct effect of concatenation lube choice. Some of the poorer-performing concatenation lubes, such as White Lightning Epic Ride, would run across the cogs abraded beyond re-use by the time a chain measured .v% habiliment. Meanwhile, good wax-based lubes would cause almost no measurable wear to the cogs with the same chain elongation.

More often than not speaking, for 10-, xi- and 12-speed drivetrain users, replace your concatenation when it measures .5%, and y'all'll be fine with re-using the existing cassette and chainrings. And you should get three chains to that one cassette, and mayhap as many every bit six bondage to the chainrings. Await till the chain measures .75% and you'll likely demand at least a new cassette, as well.

There are many reasons why chainrings last longer and handle chain wear ameliorate than cassettes.

The discrepancy between chainrings and cassettes is because the old are typically larger and with more teeth, therefore spreading the load across a greater number of teeth at any one point. On this point, yep, smaller chainrings do typically wear out faster than larger rings. Additionally, a chain volition wrap itself around more than half a chainring, while the rear derailleur dictates that at that place volition be less wrap on the cassette.

Severely worn cassettes and chainrings are easy to spot as they'll kickoff looking sparse and like shark teeth. The teeth will likely be burred, too. Plus, the chain coming off them volition exist wrecked.

In that location are no perfect tools or gauges for determining cog and chainring wear, though fitting a new chain is the surest way to reveal meaning wear as information technology will skip (when under load) and rumble on the worn teeth. That new chain will reveal gaping issues with the worn cassette, and y'all should be able to spot where the concatenation sits higher than the base of operations of the cog tooth.

For the chainring, ane test is to grab the chain where it sits on the chainring at a 3-o'clock position and pull difficult. A worn chainring will probable allow get of the chain and permit it slip forward – proving just how unsafe such a combination can be. Merely be careful to test all of this in a controlled environs before heading into a bunch dart.

Shimano components are the easiest to mensurate for wear, with new components measuring 9.5mm from tip to tip on the square-border teeth. According to Kerin, low to medium ability riders should be able to use worn cassettes and chainrings that show upwards to a 10mm distance from tip to tip, merely powerful riders may experience skipping. And by x.2mm information technology'southward too belatedly for everyone.

According to Kerin, if you keep up on your chain maintenance, use a expert lubricant, and supercede your chain before it shows significant habiliment, then you could get every bit much every bit 50,000km from your chainrings.

Summary

Well done for making it this far.

This is now the second time I've taken a deep dive on the subject of concatenation wear, trying to respond the questions that aren't asked enough. Unfortunately, like last time, I'm left with some questions that but can't exist answered. That's the problem when there are far too many variables for something to be an exact science.

Adam Kerin of Zero Friction Cycling summarises information technology well: "Every bit a general rule I prefer a quality drop-in chain wear checker. For those playing at home, checking wear via measuring elongation with calipers, a ruler, or hanging the entire chain is fraught with some challenges, and concatenation wear checking needs to be something simple and quick so that users stay on superlative of, and replace bondage earlier they become too worn and get-go eating into expensive cassettes and chainrings."

So, get yourself a trusted chain checker tool, employ information technology often, and don't be afraid to supercede your chain when you think it's time. Your drivetrain will cheers.