How can I clean gunked up sprockets?

Question

Over the past months my rear sprockets have accumulated a fair amount of gunk == chain oil + dirt + sand + hair + grass + wood chips. They look bad, and furthermore I fear the chain might be picking some of that up. I know there are specialized brushes and solutions for that, but I haven't tried them yet.

Are they effective? Are there any alternatives?

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_{Note: the necessity of such an intervention is another topic. I've ridden for decades without performing it and have been perfectly fine.}

_{This is most certainly a duplicate of something, but I just can't find it. Moderators: merge away!}

Answer 1

This answer concerns solely the situation when the cluster is removed from the rim e.g. changing a spoke or a hub.

It splits into a couple of individual spockets plus a riveted buch of them.

Clean the individual ones with a rag. Its simple, quick and easy.

The riveted ones :

• Clean with the rag.
• Then go to a place where you don't care about ugly oil stains or toxic oil ingress into soil.
• Wear a glove on the hand holding the cluster.
• Clean the major inter-spocket gunk with a piece of wire e.g. an old spoke.
• Spray the cluster with pressurized brake cleaner or any other degreaser.
• Spray with pressurized water.
• Let it dry(don't fear rust).
• Do NOT apply any lubricant to the clean cogs.

Answer 2

• clean it outside, or somewhere that falling oily dirt isn't a problem. Spread newspaper as a drop cloth if you have to.
• get the wheel out of the bike. Makes it easier.
• use a pick or smallish screwdriver or a knife to scratch large clumps of oily dirt out of between cogs. Perhaps do this over a rubbish bin.
• spray on some solvent or cleaner.
• use some soft rope or cord as glorified dental floss and pull it between each pair of cogs. There's literally a product called gear floss for this but any scrap twine will do. Dispose when it gets too dirty.
• Wipe the cog teeth with a cloth. You can generally only do the right-hand side.

Then put the wheel aside, and duplicate most of that on your jockey wheels. They hold an excessive amount of dirt for their size.

The chainrings are generally pretty okay - perhaps being further forward helps.

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I've personally had so much road dirt between the two smaller cogs that the chain would not sit well and skipped forward under high power. It wasn't also obvious from a standing position because of the black cassette, that's my excuse !

Answer 3

Voracs answer is great but if you’re reluctant to remove the cluster for whatever reason or just want to do a sub 5 minute job you can use a brush to remove the majority of the goo. This won’t be perfect but is good enough.

• Remove back wheel.
• Clean between sprockets with spoke/wire/knife/etc. That gunk is good at staining carpets, so make sure you sweep up well after.
• Use a citrus cleaner (citrus won’t effect disk rotors) and pour a small amount onto brush or dip into a small dish of cleaner. If your cleaner came in a spray bottle, spraying is fine too.
• Scrub the cluster with both radial and circular motions. Repeat a couple of times. Get the bristles between the sprockets for best results.
• Hose down with low pressure water.
• Return wheel to bike.

Answer 4

Use a suitable cleaning fluid. Solvents like petrol/gasoline/diesel/kerosene work but can be hazardous.

Plain water does not get the job done, while soapy water is good for dirt it does little for oils. Use a fluid intended for chain cleaning .

For example, I swear by Morgan Blue chain cleaner. I have used a number of citrus-based products, the Park Tool product, and Simple Green. All of these work to clean a chain but Morgan Blue tops them in my opinion for effectiveness. I have seen it available on eBay and a few internet shops.

Answer 5

For really stubborn grease-based muck, I keep a bottle of white spirit (mineral spirits) on the go. A good soak plus shaking/brushing and that will loosen the worse caked on grease (use a suitable tub to hold your parts). I then filter the solvent back into a clearly labelled bottle, using paper towel in a funnel, so you don't even consume much. Of course this also requires removal of the cassette.

Short of an ultrasonic bath it's the only way I've found to deal with oily mud inside a freehub. An ultrasonic bath would have to be pretty big to to take a container that will hold a cassette (in general you use clean water in the bath itself, solvents etc. in an inner vessel)

Finish with whatever bike-cleaning detergent you have anyway.