How important is it to clean your drivetrain?

Question

For the first time in my life I took the time to properly clean the drivetrain of a bike. How proper it was might be debatable, but for the first time I saw that the gears are not actually black.

I've owned bikes since I was a kid, when I grew out of one my parents bought me another one. I never regularly commuted by bike, but at times I was cycling quite a lot. I never though of cleaning my drivetrain and I never noticed any problems with it. I do remember lubricating it, but I'm pretty sure we didn't clean it before and we certainly didn't degrease it.

After I started cycling as my main mode of transportation, I also started reading and watching videos about bike maintenance and cycling in general. Some people seem to point out the importance of a clean drivetrain whenever they get a chance, whereas others don't seem too bothered. Cleaning your drivetrain is probably one of the cheapest things you can do to improve your bike's efficiency, so in a racing situation, I don't see why you wouldn't, but for normal commuting it doesn't seem that obvious.

For most people, the difference in efficiency isn't important. They are more interested in spending as little time and money as possible on maintaining their bike. Not cleaning your drivetrain will definitely save you time, but will it also save you money?

I understand that there are a lot of variables to consider here, but the main one is how much faster your chain and sprockets will wear out. Things like price of components, cleaning products, and time spent are also important, but much easier to research and estimate. I know quite a few commuters that never clean their drivetrains, for some, even keeping good tyre pressure is too much of a chore, and they are riding the same bike, with the same drivetrain, year after year.

On more expensive bikes with more expensive drivetrains, it's obviously more important, because the components are more expensive to replace, but is there a point where your drivetrain is so cheap to replace that you might as well not bother with the maintenance or just do the bare minimum? Like, could you get away with just lubricating the chain, without cleaning it?

When you google the subject, you find results that say that your drivetrain will last much longer if you keep it clean and lubricated, but I haven't seen anyone quantifying it. Much longer could mean anything. Is it 10%, 20% 50%, 100%, 200% or 1000% longer? Also, how much longer will your components last if you clean your drivetrain once a week, compared to once a month, or once a year?

I don't mind you sharing your opinions and personal preferences, but please do back them up with empirical data and maths. I'd like to see some proof that my efforts are worthwhile, beyond the fact that I like the feeling of riding with a clean drivetrain. Ultimately, I would like to be able to make an informed decision about how much effort I spend on bike maintenance.

Answer 1

I used to work on a fleet of cyclists' bikes who used their bikes as part of their full-time job, where it was usually raining and dirty. I changed a lot of drivetrains and oiled a lot of chains over the years. That said, I don't have any kind of empirical data to say that doing x will make your chain last y% longer. But I can speak generally about the relative factors at play, and what is worth considering when you're looking at your own personal bike / fleet and trying to decide where to invest your time and money.

First, it makes a huge difference who is riding the bike and how they ride. If they are a bigger person who likes to mash the pedals, they will burn through drivetrains much faster than a smaller person who tends to spin. Some people, the 200lb+, aggressive riders, needed new drivetrains every 2 months. A smaller, more cautious rider who tends to spin might take a year or more to wear out the same chain.

Another big factor is what kind of lube you use, and what conditions the drivetrain actually experiences. The ultimate cause of the chain wearing out is the holes for the pins will wear out as the pins rotate under tension and sand or dirt works in, effectively acting as sandpaper along the inside of those holes. How you oil the chain, and what kind of oil you use, also plays a big role in how much dirt and grime get picked up. Personally, I think a wax lube is really good at keeping grime and sand out, and makes my chain last longer while needing less cleaning. I probably apply a fresh coat about once a month. But you might also consider using a dry-season lubricant and a wet-season lubricant if you experience big seasonal swings in weather.

Ultimately, though, I think it comes down to how much you ride and what kind of relationship you want to have with your bike. Some people identify strongly as a cyclist and get a lot of personal satisfaction out of optimizing their ride and keeping their drivetrain and bike perfectly clean. You can certainly go the other way, I think the majority of people who own a bike will probably never clean the chain. Most people probably never wear through a chain, either. So if you do either, I think you're on the right track.

Answer 2

You won't find any empirical data because there are too many variables, and any riding you are doing will be far removed from any lab conditions. The other answers basically say this!

However, If you are starting to use your bike as your main mode of transportation, I'm going to posit that your main requirement is actually reliability, rather than pure cost or efficiency. For reference, below is my anecdotal experience with around 200km per week in all seasons with mudguards. I get through a couple of chains over the course of a year, and I'd estimate that the "summer" chain lasts about 50% longer than the "winter" chain (~7 months vs. ~5 months).

1. Keep your chain at least dry and lubricated. If it's been wet on a weekday, I usually just dry off the chain with an oily rag. Skipping this has, more than once, led to a seized chain in the morning. If it's been a wet week in general, then a quick clean and proper oil at the weekend. (That is, a quick spin through a chain cleaner to remove crust, dry, and then put a dot of lubricant on each link - takes about 10 mins).
2. Safety: corroded and stretched chains are much more prone to slipping or jamming in the gears. From personal experience, you can easily do quite significant damage to yourself and your belongings if this happens and at pretty low speeds.
3. You don't want to actively dislike your bike and thus your commute. Very minimal maintanence will keep your gears shifting more cleanly and reduce squeaking. Clean(er) bikes feel better and ride better; those that don't do this (as you mentioned in your post) are just being martyrs to some sort of self imposed cause.
4. Beyond the drive train, a quick check of tyres for embedded flints/glass/etc will pay dividends, especially as the seasons change and changing a tyre on the side of the road gets even less enjoyable. This will also save you on costs as your tyres and inner tubes will last a lot longer.

Given the above, think of it as an investment of your time and effort, rather than a cost: the 30 seconds it took to wipe off the chain is more than compensated by not being 15 minutes late out the door next morning. In the grand scheme of things the time taken to maintain a bike is trivial to amount of the time you will waste by not doing the work. In my case, I spent more time in A&E for a single broken arm/checkups than I've spent on bike work in 5 years of daily commuting and a fairly proactive cleaning schedule.

Answer 3

Bottom line: It depends.
There are many variables that need to be take into account. Some of them are very situation dependent.

Summarizing the question

How important is it to clean your drivetrain?

and

For most people, the difference in efficiency isn't important. They are more interested in spending as little time and money as possible on maintaining their bike. Not cleaning your drivetrain will definitely save you time, but will it also save you money?

So, according to the original post "important" is defined only by money saved.

Here is a feeble attempt to address some of the variables needed in this decision.
To calculate the value of cleaning vs replacing a chain you would have to know:

1. How much a the test chain cost (easy to know - let's go with $30.00)
2. How long the test chain would last if it were never cleaned (difficult to know and influenced by how often the bike is ridden, where it is ridden, etc. Let's say 3,000 miles)
3. How often the test chain is cleaned (one a week, month? Let's say once/week)
4. How much time it takes to clean the test chain (let's say 15 minutes)
5. How much your time is worth (arbitrary, let's say $20/hour)
6. How much time it takes to replace the test chain. (arbitrary, let's say 15 minutes)
7. How long the chain will last if it's cleaned regularly (many variables, difficult to know. Let's say twice as long 6,000 miles)
8. How many miles are ridden for a given period (let's say 1,000 miles per month)

In this model

• if the chain is never cleaned it will wear out in three months. It will cost you $30.00 to replace the chain and $5 worth of time to install it = $35.00
• If the chain is cleaned once each week it will wear out in six months. It will cost you 24 weeks times $5 in time to clean it = $120.00 and then replace the chain at the end of six months + $35.00 total after six months = $155.00

This is a simple model with several factors left out, wear on the rest of the drivetrain as one example. You'd have to know how long the drive train would last if the test chain was never cleaned and how long it would last if the test chain was cleaned at a set interval.

Throw these variables into a spreadsheet, play with the numbers so that they match your situation. Maybe add some numbers for drivetrain wear.
See how it comes out for you

Answer 4

I raced MTB as a kid and would just hope the running over rivers and the odd rainy day would clean the thing. The odd spray of WD40 was all we needed. It's important to note that I was young and my leg strength wasnt going to be snapping chains anytime soon.

However as an adult, I have snapped brand new chains on my MTB that I look after like a newborn baby, and I have had no issues on cheap commuters that I drop some lube on it every 8 months.

Ultimately, play with your bike when you want.