“The chains are narrower now, and people are not weaker. “Through the years, the replacement standards have changed,” he says.
Jones brings up the point that the parameters for chain wear have changed as drivetrains have. Whichever way you choose to measure a chain, be sure to not include any Masterlink, quicklink or ‘Powerlock’ which may be installed. Holding a ruler perfectly straight while lining it up to measure 1/8in is difficult, and with this, chain checker tools provide a far simpler and quicker ‘go or no-go’ result. That same chain on a ruler shows it is past 12in long, but knowing exactly how far past is pretty fiddly to measure And anything past 12, 1/8inches (one percent) has been worn to death and so a new cassette is likely needed. So therefore anything past 12, 1/16 inches (0.5 percent) would be the time to replace a chain. In reality though, you want to replace the chain before this point. The number most commonly agreed on for a worn chain is one percent elongation between links. Using a ruler, a new chain should measure exactly 12 inches across 12 links, from middle of pin to middle of pin. Which method you should use is the cause of much internet debate. Measuring for chain wear is done with a chain checking tool or accurate ruler/tape measure. replace this chain often.” How do I measure for wear? Why not just replace both (and get more wear)? But consider the nice SRAM XX1 cassette, which is about eight times the cost of a chain. A budget Shimano cassette is nearly as much as the cheap chain. “It’s also a consideration of the cost of the cassette and chain. How much is your drivetrain worth? some cassettes, such as those for SRAM XX1/X01, are in the hundredsĬalvin Jones of Park Tool raises an important point in regards to costs of replacement parts. On this point, we’ve heard of WorldTour teams getting three seasons of use out of the same chainrings and cassettes, purely from replacing chains before they become worn. So if you replace a chain before it’s worn out, the gears on the cassette and chainring last much longer.”
“The chain is very efficient at making the gears match the pitch of the chain. “If you put an old worn out chain on a new cassette, you can wear out that cassette in just a few rides,” says Nick Murdick, hard goods product line manager at Shimano America. Too much wear, and the chain will start skipping over the top of the cog. As the pitch increases, the chain rolls higher up on the tooth and causes rapidly increased cog wear as the point of contact is reduced. This is because a new chain at a 0.5in pitch is designed to sit deep into the cog. Perhaps most importantly though, chain wear can cost you big bucks if left too long. Additionally, a severely worn chain is weaker and there’s nothing fun about a snapped chain under power. Why should I care?Ĭhain wear will lead to poor shifting and lost efficiency. This isn’t as easy to measure, but this side to side chain wear will lead to slow and inconsistent shifting long before any pin wear is seen. It’s often stated that a worn chain is when it reaches one percent growth from the original 0.5in (12.7mm) pitch.Īnother type of chain is wear is ‘slop’. Overtime, the inner diameter of these bushings increase and the pins groove out. This is the most important type of chain wear, and the growth comes from the bushings wearing with the chain pins. 89mm in the previous photo, there is clearly some on the pins to be seenĬhain wear is commonly referred to as ‘chain stretch’, because the chain’s pitch grows in length as it wears.