Is a dirty chain a drag?
 

Well, actually, no. At least according to Ceramic Speed and GCN


The TL;DR version: A fairly filthy chain adds about 1 watt of drag over a clean new chain. Simulated rain adds around 0.5 watts. It would have been interesting to see what would happen with an unlubricated chain.

Bottom line, it seems that all the murdered electrons over chain lubrication have died in vain.

What a relief, one more thing I do not have to start worrying about.

Surprised me! I've always kept chains clean and well-lubed, figuring it was lots more efficient. Will continue to do so, to slow down wear, but how little difference being clean makes caught me off guard.

After all this time I wasn't going to start worrying, my experience has shown that a mucky oily chain is still doing the business. Obviously there are limits - excessive muck is unseemly, and chain cleaning is still good for those days you don't feel like fighting the weather, or if you have a sore knee.

While a dirty chain may not significantly increase "drag," it does contribute to drivetrain wear. Keep it clean, and your drivetrain components will last much longer.

I’m not sure you have the evidence to make the statement that a dirty chain increases drivetrain wear. The video shows that a dirty chain decreases power output by 1 W. The decrease is due to an increase in friction. Friction is a measure of the wear of the components. If a dirty chain significantly increases drivetrain wear, it would show in the decrease in the power output like that seen when they dropped sand onto the chain. The power output dropped in that case by 12W which is significant, although I would say that putting that much sand on a chain would be next to impossible even in the wettest ride.

I’m not advocating for riding around with dirty chains. There are other reasons not to do that but obsessing over chain and drivetrain cleanliness is a fool’s errand.

I never thought a dirty chain was a big drag on my power. The only reasonable reasons to me for keeping a clean chain is aesthetics. And not getting a black mark on my calf or socks that is hard to clean off. Or keep me from getting gunk all over my fingers for the very rare times I might have to fix a chain drop.

Viscosity and pumping losses even with fresh clean whatever lube. Isn't Ceramic Speed selling the idea their chain lube that adds the least drag?

news flash: Sand is a form of Dirt.

Ha... Ya know it! But never underestimate the power of Placebo. Because as you know, when ever we completely clean up our bikes... They Go faster!
https://cimg1.ibsrv.net/gimg/bikefor...e48a24473.jpeg
Clean Chain, Clean Bike, Light Lube...

No. Sand is the form of dirt. Most everything else in dirt is way softer than the steel of the chain. Silicon dioxide is harder than steel.

I would also argue that their concentration of sand was much higher than would be encountered in the wild.

The used chain in the video is already fairly dirty but didn’t show much difference from a new chain.

you're now arguing with yourself.
again.
:thumb:

Riding all day and not having greasy hands, gloves, bar tape, or calves is more than worth it.

I'd wax for those reasons even if it increased my resistance (within reason).

Nope. You are missing the point. The chain provided by the GCN guy was already contaminated with sand. That small amount of contamination only reduced the efficiency by 1 W. The water/sand demonstration applied too much sand to the chain. Even if you rode across a sand dune, you are unlikely to kick that much sand up into the chain. That part was a bad demonstration.

You have my attention. I know my perceptions can be based on expectations and not real sensations. I believe I feel the difference between a chain that is well lubricated and one that isn't. I believe I feel the difference between a new chain and a worn one. Hearing that they barely make a difference makes it sound like I've been fooling myself.

And if friction and drivetrain wear are not compelling reasons to keep a chain clean, what reasons do you have?

Well, it shows that this dirty chain decreased power output by 1W.

Self respect :D

I think this chain was dirty and still well lubricated.

The difference is that the loss of efficiency due to a dirty chain is readily rectified by cleaning the chain, while the damage to the drivetrain is permanent and cumulative.

And your hands (and some clothes) will stay cleaner as well.

But arguably vanishingly minimal, as demonstrated by the tiny amount of friction loss shown in the tests. Certainly insignificant, given how slowly chains wear.

FWIW, I haven't used any chain-cleaning device in decades. When I hear a chain start to squeak, I drip some chain oil onto a plastic produce bag, grab the chain with the bag, and backpedal until it looks as if the chain is lightly coated. I wipe off the excess and ride.

That's it until the chain squeaks again, many hundreds of miles later (unless I ride in the rain at some point, which moves up the schedule.)

I'm always amazed by how long my chains last.

The 1w loss doesn’t sound like much.
Until you consider that loss is due to the addition of grinding paste, or an approximation of it.

maybe we can make this a wax vs oil thread….. again!

Barry

I will point out one thing that I didn’t see mentioned. At least it’s something I’ve taken notice of — The resultant buildup of gunk on the chain rings, gears, and derailleur pulley wheels eventually causes the chain to not seat properly on them. As such, the chain may skip, and/or not shift smoothly. — Dan

Like how long?

Interesting method of lubrication.

Only in very extreme cases.

interesting factoid. what percentage is 1 W of an average person's effort? I kinda feel like I remember my bike working better / easier after cleaning the drivetrain, especially a particularly filthy chain

is 1 W noticeable?