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Gear: 3 Ways to Stop a Chain Reaction

Bring happiness to the bike nut on your Christmas list with one of these little items, which will lengthen the time span he or she will be able to enjoy their bike without having to replace major drivetrain components. Any of these makes a perfect gift to slip inside a stocking.

Give the gift of a chain-wear gauge

The ProLink, Feedback digital, and Rohloff chain gauge will all tell you when it's time to get a new chain. Photo by Lennard Zinn
The ProLink, Feedback digital, and Rohloff chain gauge will all tell you when it's time to get a new chain. Photo by Lennard Zinn

As the rollers, pins, and plates in a chain wear, the chain lengthens. Once a single roller at the top of the cogset is driving the wheel forward, increased length between rollers leaves slack space in between the teeth following it and the rollers, so that all of the pedaling load is on that top tooth, causing it to become hook-shaped. Each tooth in turn suffers the same fate when it comes around to the top.

Once the teeth have become hook-shaped replacing the chain only creates new problems, rather than fixes that problem. A new chain will only be contacting the bottom tooth, and the ones ahead of it will be ahead of the rollers. This will cause the chain to skip under hard pedaling.

Riding with a worn chain ruins cogs and chainrings, which are more expensive, as well as more time-consuming to replace than chains. And running multiple different wheels on the same bike with a worn chain will be a costly mistake, as cogsets can be very spendy.

So the perfect stocking-stuffer is a tool that can tell the owner of the stocking when it’s time to get a new chain before he or she lets it destroy a perfectly-good set of cogs. The following three chain gauges are the best ones I have found yet, and I use them frequently with all of my bikes.

The ProGold ProLink Chain Gauge, $19, measures over six links — two more than the other two chain gauges I mention here, thus being more accurate by virtue of a bigger sample. It’s quick to use; just hook one end on a roller and swinging the long, curved tooth at the other end down into the chain. The long tooth with widely-spaced indicator marks on it allows easy visual determination of wear.

Like any good chain gauge, this tool pushes outward on a pair of rollers to determine both overall chain elongation and wear within roller joints. It spans six links, which is more than most chain gauges do, thus increasing its accuracy. The 2-inch-long tooth allows a visual determination of wear along a scale.

The Rohloff Caliber 2 Chain Gauge, $35, is even quicker to use than the ProGold. Just hook one end into the chain and let the other end drop down. There is no gauge to read; it’s a go/no-go gauge. If the tool drops all of the way down so that its edge lies flat on the chain, the chain is toast. The “A’ side has tighter tolerances for use on more expensive cogsets and cogsets made out of titanium or aluminum, which wear faster than steel.

The Feedback Sports Digital Chain Gauge, $80, measures the exact increase in length, in inches or millimeters, over the original standard specification of the chain, which is exactly one inch for every inner/outer link pair. It has an easily legible screen, and three buttons for on/off, zeroing, and changing the measurement units. The battery life is short, but it comes with a spare battery. The tool is quick and easy to use; you turn it on, squeeze it together to its minimum length and zero it. You then drop it into the chain and let it spring back so it can accurately measure the difference in length from what it should be to what it actually is.

The tool has suggestions printed on the for chain replacement at various measurements, but in my experience, they are overly generous and would lead to more cog wear than is advisable or prudent. I would replace the provided scale with:

Elongation amount                  Chain condition

0.00mm-0.35mm:                  Good

0.36mm-0.5mm:                           Monitor the chain frequently

over 0.51mm:                           Replace the chain


On my road bikes, I replace my chains immediately when: (1) the Rohloff Caliber 2’s “A” side drops fully into the chain, (2) the ProGold Chain Gauge drops to the 90 percent mark on the current tool or “9” on the new version, or (3) the Feedback digital chain gauge indicates 0.45mm or more.

However, on my mountain and cyclocross bikes, I replace chains sooner: just before the Rohloff Caliber’s “A” side drops fully into the chain, when the ProGold Chain Gauge drops to the 80 percent mark on the current tool or “6” on the new version, or when the Feedback digital chain gauge indicates 0.35mm or more. Mountain-bike and cyclocross conditions are muddier, sandier and more punishing, and cross-chaining, which puts more wear on the chain’s joints, is more common than when riding the road. A nearly-worn-out chain can become a worn-out chain in a single muddy race or on an extended, multi-day mountain bike adventure.

So give the gift of chain longevity this Christmas.

Readers can send brief technical questions directly to Lennard Zinn.

Technical writer Lennard Zinn is a frame builder (www.zinncycles.com), a former U.S. national team rider and author of numerous books on bikes and bike maintenance including the pair of successful maintenance guides “Zinn and the Art of Mountain Bike Maintenance” – now available also on DVD, and “Zinn and the Art of Road Bike Maintenance,” as well as “Zinn and the Art of Triathlon Bikes” and “Zinn’s Cycling Primer: Maintenance Tips and Skill Building for Cyclists.”

Zinn’s regular column is devoted to addressing readers’ technical questions about bikes, their care and feeding and how we as riders can use them as comfortably and efficiently as possible. Readers can send brief technical questions directly to Zinn.

Follow Lennard on Twitter.

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