A worthwile solution is to use 3 chains and rotate between them at set intervals. You can do more, but 3 pieces is the optimal solution.

Put on the first one and ride normally as always. Replace it with the second one after, let's say 500 km, and then again with the third one after another 500 km. Once you’ve completed the 3rd interval, go back to the 1st chain and repeat the process from the beginning.

To use the chains even more optimally, simply compare their lengths before each installation and put the shortest one on. It’s not always possible to keep the perfect interval length, and not every chain has to wear at the same rate.

As mentioned before, the latter depends on a variety of variables. This includes your style, your habits, the riding environment, and the quality of the chain itself, but the rule of thumb is simply to rotate between chains at set intervals.

Distance or wear metric?

It’s common to hear distance recommendations for how often you should replace your chain. But there are simply too many variables for this to be a reliable technique – and in reality, a simple difference of chain lube and maintenance can result in a longevity difference of anywhere between 500 km to 15,000 km.

Therefore, treat the above distance intervals as an entry level guidance. The further you go into the rabbit hole, the more you need to manually check it.

When keeping a check on chain wear, it’s critical to know that the wear does not happen in a linear fashion. If you get 3,000 km of riding to .25% wear, you’ll unlikely get another 3,000 km by the time the chain reaches .5% wear.

This is because most quality chains have several surface hardening treatments and low friction coatings which will wear away with use – accelerating material wear. Additionally, the contamination inside the chain’s links will increase with use.

For that, you should do a manual check on regular basis, which we will cover in the next article. If you’re a casual road rider, I’d suggest checking every couple of months, and if you ride most days of the week, then you should check it at more regular intervals again.

The slacker you are with basic chain maintenance, the more you should keep a check on wear. And be sure to increase your checking intervals during the muck of winter, too. With time, you’ll get an understanding of how long things last, and when you should be watching for wear.

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

Don’t get caught out. Be sure to check at regular time-based intervals, and don’t rely on distance as a measure. This way you should get three chains to that one cassette, and perhaps as many as six chains to the chainrings. Wait till the chain measures .75% and you’ll likely need at least a new cassette, too.

The Benefits

What are the benefits of such an approach? A significantly longer drive-train lifespan, and therefore, significant cost savings. Chains will wear relatively normally, but these are the cheapest of the whole set.

The savings lay in the much slower wear rate of cassette cogs and chainrings. Normally, after 5000 km, a chain would reach a certain stage of wear, after which the cassette would start to fade fast, as well as the chainrings.

When riding 3 chains, at the time of 5000 km, they are worn by about 33% of what it would be if you were riding with a single chain. Thus, after these 5,000 km, you are still at a stage of chain wear, which is not harmful to the cassette. Meaning, that by pressing the pedals, the chain pulls all the cassette teeth, not just one.

Now, why is it so important to rotate the chains regularly, at relatively short intervals? The answer is to get a relatively comparable wear on all 3 chains, so each fits the cassette at a given time.

Too large intervals can lead to a situation when 1st chain will still be compatible with the cassette, but the 2nd will no longer fit as the cassette has been worn too excessively with the first one. The chain will skip over the top of teeth, knocking out the entire system. Thus, all 3 chains should wear out at a fairly even rate.

Numbers

To illustrate the profitability of such a procedure, we will use some numbers to show the benefits, which are quite clear!

To simplify costs calculation, let's assume that one wears out his drivetrain within two seasons. I might be too often for you, as well as you might need to replace your bits every season. The wear rates are individual for everyone, for the reasons I have already explained some place above.

So, assuming that riding with one chain will wear out the drivetrain in two seasons, then riding with 3 chains on rotation will prolong the lifespan roughly 3 times to 6 seasons.

The annual cost of a drivetrain is its total purchase price divided by the number of seasons it’ll be used for. So, for single chain riding, the annual cost of all bits (cassette, chainrings, chain, derailleurs, and jockey wheels) is divided by two, whilst when riding 3 chains the total cost (including the purchase of 3 chains rather than 1) is divided by 6.

Below we present calculations of these savings for several groupsets for Road and MTB. The higher you go, the more obvious the benefits.

*Please note, the prices are actual for Nov/Dec 2022 and are averaged over the market. However, one can easily put his numbers into the calculation to get a better understanding in ones own, particular case.

Summary

1. When buying a new bike or drivetrain, get additional chains to have a total of 3 pieces.

2. Change chains regularly, approx. every 300 mls or 500 km. (Preferably, learn how to measure the wear on your chain.)

3. Make changes in sequence, or by comparing the lengths of the chains and always choosing the shortest one.

4. For ease of use, keep the chains in their original boxes and number them respectively. It is also worth noting the mileage, at which you changed the chain, and putting a sticky note on the box to control the intervals.

5. When replacing the chain, it is good to clean and lubricate the one that was removed from the bike, prior to putting it in the box. This way it'll get secured, and it will be ready for installation at any time.

6. Enjoy extended drive life and cost savings.