You’ve probably noticed that after a few bike rides, your bike’s chain starts turning black. It seems inevitable.
But you may be wondering: what’s causing it to do so?
Your bike’s chain will turn black as dirt and gunk (attracted by chain lube) start to build up on it. This problem can be compounded if you frequently apply too much lube, or are using the wrong kind for your riding conditions. Fortunately this issue can be prevented with regular cleaning.
So how do you know if you’re using the correct lubricant? And if your chain is looking pretty gross, what’s the best way to clean it?
Read on to learn more!
Table of Contents
What Turns Bike Chains Black
Bike chains turn black because the chain lubricant attracts dirt and grime, creating a pasty, gooey blackened mess over time.
That’s the short answer. The longer answer is a bit more nuanced but comes down to a few main culprits.
Roads, bike paths, trails, and sidewalks all have dirt, mud, grease, chemicals, and water that can get kicked up onto your bike chain, so it’s natural for your chain to get dirty.
Dirt happens. It’s just part of bike riding. But if your chain is getting excessively dirty very quickly there could be another factor at play: the type and amount of lubricant you’re using.
2. Excess Lubricant
You need lubricant to reduce stress and friction on your chain and cogs. Lubricants are sticky and attract dirt…exactly as they’re supposed to. The dirt sticks to the lubricant, which then flakes off of your chain so it never actually comes in contact with the chain itself. All good so far.
But here’s the rub (pardon the pun): if you use too much, that lubricant is just too thick to flake off like it’s supposed to. As it attracts all those nasty elements on the road or trail, the combination of excess lubricant and grime coats the chain in a black, gooey mess. Rather than keeping your chain turning smoothly, this tar-like paste ends up doing just the opposite.
3. Wrong Type of Lubricant
There are lubricants specifically made for bicycle chains. They are specially designed to keep your drivetrain running smoothly without gumming it up. What’s more, there are different types of chain lubes for different types of riding and different riding conditions. What this means is not any old lube will do. Choose the wrong type, and you can forget about crisp shifting. We’ll cover all of this in a bit.
Is It Okay for Bike Chains to Be Black?
The short answer is no, not really. Continuing to ride with a very dirty chain is a bad thing for several reasons. It isn’t just an eyesore; it can also sap your bike’s pedaling efficiency, prevent your gears from shifting properly, cause the chain to suddenly jump off the bike’s cogs, or even break, leaving you to push your bike along while walking or stranding you altogether.
A blackened, gunked-up chain can also drastically reduce the useful life of the chain, chainring, sprockets, and derailleurs: all of the critical and expensive parts that make up your bicycle’s drivetrain. All of that muck damages the parts it touches, both reducing pedaling efficiency, and corroding those metal components over time.
In short, letting your chain get black and gunked up and leaving it like that can decrease your cycling performance, cost you lots of money in expensive repairs, and can even be dangerous: having a chain pop off in the middle of a ride can lead to a dramatic crash—trust me, I’ve been there.
How to Prevent Your Bike Chain from Turning Black
The main thing you should do to prevent your bike chain from getting black and gunky in the first place is to properly apply the correct lubricant for your bike and the riding conditions.
It’s crucial to use a lubricant specifically made for cycling. It’s also important to choose a lube that’s made for the conditions in which you’ll be riding.
Here’s what you’ll need to know to do this properly:
1. Which Lubricants Not to Use on Your Bike Chain
The trouble is that many people think any lube will do and end up greasing or oiling their chain with products not intended as bike chain lubricants. Pro tip: Don’t do that! Here are a few classic examples:
This staple of your grandfather’s tool shed is a great product. But please don’t use WD-40 as a chain lube. Why? WD-40 is a solvent, not a lubricant. You can use it to help clean your chain, but it will also remove any other real lubricant and when it cures, you’ve got a bone-dry chain. Metal-on-metal contact with no lubricant severely reduces the life of your components.
In fairness, WD-40 now makes an actual bike chain lubricant; just don’t get it mixed up with the original product.
Vegetable, Olive, or Other Cooking Oils
Nope again. While cooking oils provide some lubrication and reduce friction slightly, they don’t do the job very effectively. They’re also very difficult to remove without a degreaser (how hard is it to remove cooking oil from your hands in the kitchen without a lot of soap?) Leave them in your pantry.
As they’re made with organic ingredients (rather than synthetic), they may also go rancid over time.
Your bike’s drivetrain shouldn’t smell like a dirty deep fryer!
This could be tempting, as there are bike-specific greases on the market. These are used on threaded components (such as the pedals), or for parts of your bike that are not exposed to the elements, like bearings in the headset or bottom bracket.
They are most definitely not for chains—grease will certainly attract dirt, but it won’t dry and flake off like proper chain lube will.
2. Which Lubricants to Use on Your Bike Chain
While lubricants made for chains may seem more expensive than some of the “don’ts” listed above, a little goes a long way. And high-quality chain lubricant will save you money in the long run by helping you get as much mileage as possible out of your drivetrain components.
That said, there are many different kinds of bike lubes, but to make things simple, let’s break these down into two basic categories: wet lube and dry lube.
As the name suggests, wet lubes are intended for riding in wet conditions. But they’re also often used for year-round or multi-season riding conditions, for example on a commuter bike, hybrid bike, or for the recreational road bike. They are typically made of synthetic oils with additional additives, such as PTFE (Teflon).
Wet lubes are great all-purpose lubricants that hold up well and are resistant to getting washed off in rainy conditions. This durability and resistance to water is attributed to wet lube’s thicker formula, which also makes it more prone to collecting dirt and grime—back to our original problem.
However, they are not as prone to collecting dirt and grime as non-bike specific lubricants, and proper application can reduce this issue. What I mean by proper application is this: Don’t overdo the lube!
One of the major causes of black chain, even when using a good product, is overdoing it. The trick is to apply evenly but conservatively. Fortunately, lubricants designed for bike chains tend to come in bottles with application tips that make this easy.
You’ve probably guessed this already: these are intended for dry conditions. Dry lubricants are typically made of a much smaller percentage of actual lubricant than wet lubes. Frequently, they’ll comprise roughly 10 percent lubricant—synthetic oils and additives such as PTFE or ceramic—with the remaining 90 percent being made of a carrier fluid.
The carrier fluid allows the product to be applied much like the wet lube, but then it evaporates, leaving a much drier chain behind.
Because of this, dry lubes are very resistant to dirt and grime. The downside is that they also wash off easily when they get wet.
Choose dry lube if you ride mostly in dusty, dry conditions, such as normal road, mountain, or gravel biking, where tons of dust and dry dirt are constantly getting kicked up.
3. How to Apply Lube to Your Bike Chain
With either type of lube, you want to apply evenly but sparingly. Remember the cardinal rule: Don’t overdo the lube!
A tried-and-true method is to elevate your bike’s back wheel while still being able to turn the pedals and cranks. A bike stand is ideal, but if you don’t have one, you can improvise. Note that you’ll want to apply lube to a clean chain (more on that below).
Once you’ve got the bike where you want it, grab a pedal, and slowly turn the cranks backward while applying the lubricant to the chain’s links and rollers. Make sure to apply lube to the inside of the chain, not the outside: this is the part that contacts the drivetrain after all.
Move the chain through one complete cycle, ensuring you’ve coated every link. An easy way to know when you’ve made a complete cycle is to start and end at your chain’s master link: the link that can be opened to remove your chain. This way you know you won’t overdo it with the lube.
When you’re finished, take a rag and gently wipe down the chain, removing any excess lube. Turn the cranks and shift through the full range of gears so the lube can coat all the chainrings in your cassette.
That’s it! With wet lubes you’re good to go. With dry lubes you’ll want to let it sit for 10-15 minutes before riding. I like to apply chain lube after riding, not before. This ensures it has plenty of time to soak into the chain and dry before my next ride.
How to Clean and Maintain a Chain and Drivetrain
Alright, so your chain is filthy. You’ve been riding for a while and always use bicycle chain lube, but you’ve been piling it on and now you’re all gunked up. Never fear! We can fix this.
Using a hose, soak your chain and drivetrain with water, but do this using very low pressure. High pressure can force water into hubs, bottom brackets, and other places you don’t want to get wet.
Then spray the bike chain and other drivetrain components down with a degreaser. You can buy bike specific ones, but here’s a case where something from your local hardware dealer will do. I like Simple Green.
After this, take a brush to the drivetrain—an old toothbrush will do, though you can use something with stiff bristles if you like. Use the brush thoroughly on the chain, cogs, chainring, and moving parts of the derailleurs. Rinse again, then wipe down with a clean rag. Let it sit until totally dry, then apply lube using the method described above.
You can also use a chain washer, a convenient tool that can be used without removing anything from the bike.
Some people like to keep their entire bike shiny, clean and like-new for its entire life. This is great, but if you’re not one of those people, at least make sure to regularly clean your drivetrain. Done frequently, cleaning and lubricating can take very little time and it helps avoid the dreaded black chain.
I like to do a quick check after each ride. Usually all that’s needed is a quick wipe down of the chain and drivetrain with a rag. Each lubricant is different, but most of them do not need to be applied for every ride—check the recommendations for the brand and type of lube you use.
After every three or four rides, I’ll use a little degreaser, a brush, and a rag to do a slightly more detailed job, and reapply lube as needed. But always remember a little goes a long way, and you should wipe off the excess.
If riding conditions are terrible and your bike gets completely covered in dirt and mud, such as in a cyclocross race, a full cleaning will be necessary. Aside from these situations, you can go a few rides before needing to do a deep clean.
Keep your grime and lube situation in check and you’ll have much more time to enjoy actually riding your bike. And that’s our ultimate goal, isn’t it?