What is the best solvent to use at home for cleaning bike parts like bottom brackets and such? I've see mechanics use paint thinner and heard other cyclist say they use diesel fuel. What do the BF pros say?

OMS (odorless mineral spirits)

Elbow grease first and foremost. Mineral spirits for tough spots.

Depends. At home in the basement I try to trap old crap in a rag or paper towel first. WD-40 or Clean Streak are my go to sprays for this.


For soaking of flushing needs I have an industrial tank in my garage. But before this tool I used mineral spirits. The neat thing about MS is that if you leave the tub/jar for a while the grit settles out and you can pour off very clean MS and recycle a lot over and over. Andy

I use kerosene.

This is a trick question... isn't it?

Mechanics use MEK: Methyl ethyl ketone (butanone), a solvent. Not safe for use or storage at home.

Oderless Mineral Spirits aren't safe either(<see the pdf safety sheet) although slightly better than MEK. No solvent is safe for use outside of the shop. Or... safe to be stored anywhere around a home.

I have used a little choke cleaner (from a spray can) to clean parts. The choke cleaner just melts the dry grease off. It must be used outside... ONLY.

Other than that... simple green in a spray bottle, rubber (dish washing gloves) and a stiff brush works great.

I'd like to point out that as a hapless resident of California, OMS is no longer an option. There hasn't been any on store shelves since perhaps 2015, and if you manage to find a store that stocks anything labeled "mineral spirits," it's an ultra-low-VOC formulation that's pretty much good for nothing at all.

I use Kleen Strip Aerosol Degreaser, followed by good old fashion Brake Cleaner to wash off the residue inevitably left behind by the Degreaser. It's an imperfect solution, but at least I can still buy the stuff. I depleted my supply of real OMS over a year ago.

Using MEK is like using an atomic bomb to remove a tree stump. It will give you a nose bleed without a respirator and good ventilation.

I don't disagree. But MEK was used for decades in factories and shops everywhere. No respirator, no gloves, not even a fan before maybe 1980. Stoddard solvent was another favorite.... that was even used for dry cleaning... later replaced with PERC Perchloroethylene (tetrachloroethylene).

All are fine solvents when used by trained personal. None... belong in homes.

Unfortunately the ban on mineral spirits, white spirits, etc., in Southern California limits your options. That's over-regulation that will tempt some folks to use much more hazardous materials.

Keep in mind that "paint thinner" is such a generic and vague term it can mean anything from alcohol to petroleum to water based solvents. Even "mineral spirits" is an imprecise term and the actual ingredients varied quite a bit, including in flash point.

If I was forced to do without mineral spirits I'd use citrus or simple green type cleaners, and 91% isopropyl alcohol when needed for degreasing and removing any residue from other water based cleaners (which includes the citrus and simple green type stuff). For my spinner brush type chain cleaning tool I use a homebrew of water based degreaser (Dawn or Stanley) mixed with 91% isopropyl alcohol. If using 91% isopropyl for anything more than dampening a cotton swab or cotton ball sized pad or cloth, it's best to take it outdoors away from ignition sources. Flaming alcohol can be scary stuff because it's almost impossible to see in bright light.

MEK is so hazardous it should never be mentioned in the context of an introductory level discussion other than to warn folks to avoid it completely. If it's necessary to explain why, it's the wrong material for the job. Even if you could use it, MEK is probably the wrong stuff for most bike maintenance. It can damage many plastics and is used in welding some plastics together.

For complete information it's preferable to refer to NIOSH information -- readily available online -- in preference to a Material Safety Data Sheet. MSDSs are prepared by manufacturers and sellers, and are prone to errors and deliberate omissions. A manufacturer can omit information they believe to be proprietary or trade secrets, legally or not, correctly or not, and the end user might never know. NIOSH info is more complete, unbiased and non-partisan.

Diesel works well. It's easily available in any quantity you want without restriction. It does leave a residue, but that is not necessarily a bad thing. Importantly, its flash point means it won't ignite easily with just a spark.

Well, carbon tetrachloride was also a common solvent and household spot remover in the past but it doesn't make it sensible, or even legal, to use now.

Stoddard Solvent is another name for narrower volatility range version of odorless mineral spirits and was replaced by "perc" and "trichlor" due to it's flammability, not due to it's toxicity.

Finally, MEK is a polar and thus a poor grease and oil solvent as are the various low alcohols like methanol and IPA.

Very common. We always had a bottle of carbon tet in the garage at home as well as some of these.

https://cf.collectorsweekly.com/stori...URImzSfGgA.jpg

Keep the brake cleaner away from plastics.

Like Andy, a rag, and a touch of WD-40 work 99% of the time for me.

WD-40 for me also. Liquid laundry detergent and warm water if it isn't too grimy.

I use mostly the citrus based cleaners now, but opt for mineral spirits or acetone occasionally.

A word about MEK: It is hazardous mostly because of it's flammability and volatility, not its toxicity. Its primary toxic effect is a temporary narcosis, which is why abusers like it. It will get you drunk in no time if used without ventilation. I agree that it's not the right solvent for bike work, there are much more effective products.

Probably not. MEK (butan-2-one or 2-butanone) is relatively polar and a poor solvent for grease...which is nonpolar. It also has a low flash point (-9°C). It is also a slight lacrymator (eye irritant).

I agree that its use at home is not safe.

Commercial part cleaning tanks use mixtures closer to odorless mineral spirits which is nonpolar and has a much higher flash point (40°C to 50°C). From a toxicity standpoint, it's not terribly toxic, especially the odorless variety.

For the metrically challenged, -9°C is 16°F and 40°C is 104°F.

And, since it will invariably come up, don't use gasoline! It's toxic and highly flammable (flashpoint of -45°C or -42°C). It can be easily ignited at any temperature that we would normally use it in.

While I do like using Simple Green for everything from external cleaning to chain cleaning, I would NOT use it for bearing surfaces. Brake cleaner is a good solvents to use after degreaser.

It's a bad idea to use any solvent on a bottom bracket (i presume you are using Shimano HT2 cups here?) Any solvent that gets past the seals will thin and strip the grease inside the bearings containers. Any external dirt on the cups should be wiped off with a rag/dry towel. Solvents are for other parts like chains. Keep them away from anything with bearings that includes hubs,headsets,bottom brackets,pedal spindles.

Sealed bearings.
But old school loose bearings can be cleaned with solvent

It is a perverse law of the universe that the more toxic and flammable a solvent/degreaser, the better it works.

Water-based solvents (including anything green) are useless - this is basic chemistry.

White gas (camp fuel) is an outstanding solvent, but is volatile and it can blow you up. I've almost done it. I use it sparingly for tough jobs such as removing decals and road tar.

Mineral spirits (varsol) is a good compromise.

White gas...aka Coleman fuel, naphtha, white spirits, mineral turpentine, Stodard solvent, etc....is almost the same thing as "mineral spirits". It's not "odorless" because it has more aromatic compounds in it but it's still mineral spirits with similar properties and flashpoint. The flashpoint is on the lower end of the scale I gave above. Still pretty safe to use with adequate ventilation. It will ignite but so will odorless mineral spirits.

Although I'm not a fan of "green" degreasers, they aren't completely useless. They just require more of the degreaser and they require more rinsing with water then more rinsing with something to remove the water. Mineral spirits is more of a "one and done" solvent.

I will also say that diesel and kerosene may work as relatively safe solvents but they are much more oily and less easy to evaporate than mineral spirits are. Gasoline is a very unsafe solvent to use under any conditions because of it's extreme flammability.

Dawn dish soap for chain, crank and cassette. The cheap small bottle at the dollar tree. But the bottom bracket, I generally use wd40 if it really needs it.


**I'm not a pro, just love cycling.