Should I be worried about sand in the chain?

Question

This is about my daughter's (10yo) bike. It's fairly new, maybe about a year old (bought it off a relative who changed her mind). We're no active sporting family, but with this social distancing and working from home thing we've started to take long walks every day - about 2h per day or so. And my daughter rides along with her bike most of the days. So - light but regular usage.

Now, most of the days here have been nice and sunny, but last Friday we got some rain while walking. The next day, Saturday, she started to complain that her bike has become squeaky. Had to agree, the chain was squeaking.

So on Sunday I went to the nearest hardware store and bought a can of the only chain oil they had (this product). It's not specifically aimed at bicycles but judging by the many bicycle pictures on their webpage, it certainly can be used there.

My daughter didn't ride her bike on Monday, but on Tuesday we took it out again and I sprayed the chain thoroughly. Indeed, the bicycle became whisper quiet. Nice.

Then today (Wednesday) we went somewhere a little different and visited a nearby patch of a forest. Dirt paths, hills, was fun. But soon after we got out my daughter again started to complain that it's gotten harder to pedal and the chain is making noise again. This time it wasn't squeaking but... I don't know the English word for it, but it's the sound that sand makes when it's between moving parts. "Gritting"? "Grating"? "Grinding"? Not sure. Anyways, yeah, the chain and gears do look like they've got some sand and dirt stuck to them which would explain it all.

Now... I don't know what to do. I could try applying more of the spray oil, but my intuition says that it won't help much, if not actively make things worse. Reading on this site reveals that people are using some sort of "degreasers" and giving their chains thorough cleaning with a toothbrush... Which seems like way too much hassle and overkill. As a kid I've spent years riding my bike through whatever and probably lubricated the chain twice in total, so this sounds like it shouldn't be an issue. Perhaps it will just dry off or get ground off in a few days and that will be that? Or maybe I've overlubricated the chain or used the wrong substance or something and now there is indeed trouble brewing?

Any advice on what to do?

Update:

What I ended up doing was a lot simpler and will probably earn me at least a few disappointed sighs from the experts here. I remembered that there's a gas station nearby where they have free access to running water for washing your windshield/bike/whatever. And I just poured some on the chain and gears and the noise stopped and the bicycle is running nicely now. I'm keeping an ear out to see if it starts squeaking again - if it does, I'll apply a bit of oil again and this time - wipe it off!

Answer 1

It was the right thing to use the lube for the chain.

I do not know the particular product but in general spray lubes have the tendency to become too plentiful on the outside of the chain. This film of lube will become sticky as the solvents in the spray are dissolved.

The grinding noise from the drive train may come from sand or grit sticking to the outside of the chain. The fix is to remove it. You do not have to use the more complicated methods meant for bikes where drive train efficiency and longevity are important.

If you have a degreaser or a light oil like WD-40 at hand it helps to soften the old lube. Otherwise use warm water with dish washing detergent. Spray the degreaser or light oil on the chain. A stick is often useful to scrape off old dirt and grease from sprockets and chain ring. Use an old brush or an old rag with the soapy water to clean off old lube (and detergents). That doesn't have to be super thorough. Rinse with clear water.

When you cleaned the chain this way, apply your 'Krown' spray lube again. Spin the gears or let your child ride a few rounds on your yard (not through dirt) to work the lube into the rollers. Then wipe off excess lube from the chain. Do this last part quickly after applying, while the spray on your chain is still fluid. After a while the light oils in it will disappear and only the sticky lube will remain.

We want the lube inside the chain, between rollers, not on the outside where it attracts dirt and grit.

shortcut:

If you are in a hurry, it might be enough to spray the chain again with the 'Krown' lube you have. It will soften the grease on the chain. Then wipe it all off with a dirty rag. Wipe also the sprocket and chain ring. Be careful not to pinch your fingers!

This quick-and-dirty method will get grit into the chain rollers, and reduce their life. But for the use you describe, that will not matter.

Answer 2

The thing to do is to clean the chain before lubricating it: the combination of lubricant and sand is effectively a grinding paste that will wear out the chain quickly. In particular, you need to clean the parts that aren't exposed (the contact between the chain rivets and rollers).

I've used a foaming spray-on degreaser that does an OK job and doesn't require any handwork. There are gadgets that can clip onto a chain and use liquid degreaser to scrub the chain more thoroughly, but that sounds like overkill for you.

Answer 3

You need to visit a bike store or search online and buy some bike-specific lube. And there are several choices, roughly divided into "wet", "dry", and "intermediate" (though there is no consistent term for this latter category).

"Wet" lube is relatively heavy with oil, similar, at least on first glance, to motor oil. It leaves a glistening oily coating.

"Dry" lube is much thinner and less viscous, and some dry lubes (often called "wax lubes") leave a much thinner wax-like coating on the chain.

The intermediate lubes are kinda in-between.

The point is that you choose your lube based on conditions. If it is wet and a lot of water is apt to spray onto the chain then a "wet" lube is best, to protect the chain from moisture and to maintain lubrication as the rain tries to wash it off.

But the problem with a "wet" lube is that it's inherently oily, and this causes it to collect dust and dirt and sand as you ride, and this contamination is bad for the chain and sprockets.

A "dry" lube, on the other hand, resists collecting contaminants, but it's not a protective against moisture.

The intermediate lubes attempt to split the difference.

My guess is that your daughter does not ride in the rain very much, so using a "wet" lube (and the stuff you found was probably very much on the "wet" end of the spectrum) is probably not a good idea. Instead you should use a degreaser of some sort (WD-40 works pretty well) on the chain every few weeks, and then lube with an intermediate or dry lube.

I'll note that there's a thing called a "chain washer" or "chain scruber" which is ideal for cleaning a chain, but it only works with derailleur-style chains, and I'm guessing your daughter's bike is a single-speed.

Answer 4

It depends on the time frame you are talking about.

In short term, sand doesn't mind. Whenever you have wet surface, dust and sand will stick to it and you cannot do anything about it.

In long term, the sand and dust works like quite effective abbrasive that wears down chain and all chainwheels it touches. So not-addressing sand/dust in chain reduces parts life significantly.

• If the chain is really dirty and full of grease/oil/dust goo, use dirty rough cloth or brush and wipe the chain clean from the mess. For cleaning the chainwheels, old hard toothbrush is perfect tool.
• Then apply cheap oil (household, WD40,...) and wipe the chain clean using less dirty cloth. Same apply to all chainwheels.
• Use the chain cleaner mentioned in Daniel's answer filled with water and some detergent. Clean the wheels as well. Then wipe the chain dry with clean cloth.
• Lube the chain with chain oil and then wipe it dry with clean cloth.

The last step is to keep oil only in the places where it is actually needed (in between the conectors) while having the places where the oil is useless dry, so the dist and sand cannot stick there easily.

Answer 5

Looking at page 8 of https://www.skf.com/binary/81-156296/SKF_KrownCatalogRevise_10Dec14_FNL.pdf

I would suspect that this is intended for motorbike roller chain. It is not stated anywhere, but the images show quite chunky rollers. Fundamentally this is the same principal as bicycle chain, but the loads and the rotation speed will be far less than a motorbike, or other chain-driven machinery. Other uses like the stated "Open gears" are quite different to the internals of a roller. This spray stuff will be more sticky and less able to "wick" into the inside of the roller where it needs to get to.

Upshot any lubricant is better than none, but the sand is being attracted to the lube and acting as abrasive grinding paste.

I suspect that the lube is more on the outside of the chain than inside the rollers where it needs to be effective. Since its an aerosol, you're going risk over-spraying onto the rear wheel and the rear brake surface (either rim track or rotor) Use a rag to catch all the overspray.

Start by cleaning the chain with detergent and warm water, or degreaser first then warm water. Let it dry by air for a short while - too long and rust will start to form. A hairdryer can accelerate drying, but mind the paint and tyres.

I would suggest getting one of those narrow tubes that fit inside the nozzle of an aerosol can, and let you focus the spray down to exactly the roller.

^{Example of aerosol straws}

Once you've dabbed lube onto every roller (and yes there are about 100 rollers in the chain on an adult's bike, maybe 70-80 on a smaller kids bike) then backpedal for a moment or two, and then wipe off the excess lube from the outside. Do note the lube could drip or fling off, so do this all outside.

As for future use, try avoid getting the bike in sand, and if it does get sandy wash it all off with normal water as early as possible - use your water bottle right there if there's no more sand coming up. Then do a chain lube at the first opportunity, probably when you return home, or that night.