Condensed answer: The cogs of a bike cassette do not require lubrication due to their structure and function. Lubricating them can cause harm by creating a sticky layer attracting dirt.
Reasons Not To Lubricate a Cassette
1. Dirt Accumulation
Extra lubrication creates sticky residue collecting contaminations from the road. Over time, the result is thick black gunk “polluting” the chain’s links and preventing it from moving smoothly.
If you purposefully lubricate the cassette, you increase its chances of getting dirty and extend your bike maintenance/cleaning routine.
2. The Chain Is Already Lubricated
When a chain is sufficiently lubricated, some of the oil inevitably gets on the rear cogs. Thus, the chain lubricates the cassette even if you don’t want it to.
Ultimately, if your chain is lubricated, so is your cassette.
3. The Friction Isn’t That Great
The chain slides against the cassette during shifting, but once on the proper cog, it bites against the teeth and stays locked-in.
Or in other words, the chain isn’t rubbing against the cassette most of the time.
This peculiarity lowers the need for lubricating the cogs of the cassette or freewheel even further.
FAQ: Should I lube the lock-ring of the cassette?
Some people like to grease the lock-ring of the cassette to facilitate future assembly and disassembly, but it’s not mandatory to do so.
FAQ: Should I lube the freehub body?
The cassette slides on the freehub body and creates a “metal on metal” situation which by definition requires grease. Therefore, you can grease the freehub body if you want to.
Technically, if the freehub body is made of alloy and the cassette is steel, galvanic corrosion can take place.
Galvanic corrosion is a deterioration process occurring when two dissimilar metals are in contact and in the presence of a conductor like water.
In this case, aluminum is the metal giving up electrons even though by itself it’s more corrosion resistant than steel.
However, this is a custom scenario known as preferential corrosion.
A layer of grease on the freehub body would prevent this outcome by separating the two surfaces.
Nonetheless, galvanic corrosion between a cassette and a freehub body is an extremely rare scenario for two reasons:
- The inside of the cassette and the outside of the freehub body are treated against corrosion;
- The cassette is a “consumable” which demands fairly frequent replacement when used intensively. In consequence, there isn’t enough time for galvanic corrosion to take place.
Ultimately, the need for greasing the freehub body is low, but doing so isn’t a harmful practice.
For this particular purpose, you can use lithium grease, marine grease, and, of course, bike-specific models.
The Insides Of The Cassette Hub Have To Be Lubricated
The ratchet mechanism, the pawls, and the bearings of the hub should be lubricated as required by the manufacturer.
Lubrication is necessary because there are many moving parts going against each other.
More often than not, the lubrication of choice is grease due to its high viscosity and water-repellent functions.
Having said that, some hubs are non-serviceable and require complete replacement upon failure as there is no way to open and close them without risking structural disintegration.
If you’re interested in learning about the structure of a bicycle rear hub, you can check out this article.
FAQ: I have a freewheel, not a cassette. Should I lubricate it?
Freewheels “carry” a ratcheting mechanism whereas cassettes are just a “collection of cogs”.
If you’re experiencing problems with the coasting of your bike (e.g., the pedals spin, but the rear wheel doesn’t), you will have to “un-seize” the freewheel.
The simplest and fastest way to do this would be to spray a degreaser into the bearings through the crack at the back of the freewheel’s body.
Nevertheless, you’re not expected to routinely disassemble and lubricate the freewheel. You could if you want to, but the price of a freewheel does not justify the labor cost and the time.
Chances are that the cogs on the freewheel will wear out long before you have to service the internals.
FAQ: Should I lube the chainrings of my bike?
The same reasoning can be applied to the chainrings – due to their role in the drivetrain, and the fact that the chain is already lubricated, there’s no need to lube them.
Keeping them clean and tight is a sufficient maintenance protocol.
How Can I Keep My Cassette As Clean As Possible
You can dismount the cassette to clean it or keep it on the bike. Removing it facilitates the procedure and gives better results but takes more time and effort.
To remove the cassette, you will need a chain whip and a cassette or a freewheel tool.
If that’s the route you want to take, you can use the following method to clean the cassette:
Step 1: Remove the cassette
Step 2: Soak the cassette in Kerosene(Paraffin)
Step 3: Wash the cassette with white spirits, gasoline, or brake cleaner.
This approach is known to produce a very clean cassette but has a major downside – it involves harmful substances.
If you don’t want to remove the cassette, you can follow the guideline below:
Step 1: Spray the cassette with a degreaser such as WD-40. Make sure that the substance doesn’t reach the hub’s bearings.
Step 2: Slide a brush or a dedicated cassette cleaner between each cog and rotate the cassette. You will see a lot of black gunk accumulate on the brush/cleaner.
Tip: If you don’t want to spend extra money on a “bike-specific” brush, you can buy one designed for cleaning car wheels. Most of them can fit between the sprockets just fine.
Alternatively, if you don’t have access to any of the above, you could take an old cotton T-shirt, cut it into long lines and use them to reach between the cassette’s cogs.
Step 3: Spray additional degreaser on the cogs and wipe them with a dry cotton rag.
To remove the cassette or not?
Removing the cassette produces better results, but the gains aren’t big enough to make a huge difference.
If the bike is old and neglected, it makes sense to remove the cassette and give it a good cleaning.
But if the machine is used frequently and maintained, cleaning the cassette periodically without getting it off the wheel will be sufficient.
How can I keep my cassette shining for longer?
There isn’t a product that could keep the cassette as clean as it gets after degreasing. Nonetheless, the tips below will reduce the level of contamination.
1. Don’t use too much chain lubrication
Contrary to popular opinion, the parts of the chain that need the most lubrication are on the inside.
Lube on the outside of the chain isn’t very useful. Hence why it’s recommended to avoid over-lubrication.
Clean the chain with a rag after lubricating it.
2. Do a short cassette cleaning after every ride
You can purchase a cheap toothbrush and use it to remove the visible gunk accumulated on the cassette after a ride.
The goal isn’t to get a super clean cassette, but to eliminate the peripheral contamination. As they say, a little goes a long way.
3. Don’t lubricate your chain too frequently
Cyclists obsessed with keeping their machine in perfect condition all the time tend to do “over-maintenance” or in simpler words – they do too much.
You don’t have to lubricate your chain after every ride.
4. Use a quality degreaser
When cleaning your cassette, use a strong degreaser.
5. Switch to nickel-plated cassettes
Black and grey cassettes do not shine as much as the nickel-plated versions even when you clean them. If you want your cassette to be shining, you will have to go for a nickel-plated one.