Dish Washing SoapDishwashing Liquid
Water with a few drops of dish washing soapdishwashing liquid is good to clean superficial dirt from a chain. Especially when also using an old rag fortfor mechanical cleaning. Hot water with dish washing liquid has decent
Degreaser
Before I apply new chain lube I rather have my chain slightly cleaner and use a home made degreaser. It comprises of water, alcohol (eg isopropanol, methylated alcohol), baking soda, and dish washing up soapliquid.
I used this degreaser superficially. I want it to reduce surface muck. Especially grit and rock dust mixed with lube. To avoid theseThese hard, and fine particles cause wear by abrasion. The cleaning ought to getavoid that these particles getting flushed between the rollers when applying fresh lube.
I do not want degreaser to get between the rollers. There is next to no chance to get contamination out anyway. But it might degrade the lube where it is needed.
Also fort thusfor this reason it is important to thoroughly rinse after degreaser use.
WD40
To prevent misunderstandings: The property of WD40 of interest here is it'sthe following: it is a light oil in a spray tin and, it is inexpensive, and readily available. It is also not particularly hazardous, unlike paint thinner. OneFor the sake of this discussion one may replace it with any other product with thesesimilar properties.
WD40 on a dirty rag, and some well aimed squirts, is fantastic to remove thick grime and greasy muck. It's an easy way to get a clean looking shiny drivetrain.
One can also use larger quantities to deeply clean a chain. Degreaser is then required to remove the thinned grime and lube. However, WD 40 will get between the rollers and dissolve in the lube there. I do not recommend this on a fairly new chain (<50 h of use). The thick lubeslube manufacturers use is much better than anything we might apply thereourselves. (Except for maybe some exotic methods for one time use in pro racing like UFO.)
My experience with deep WD40 cleaning is a considerably reduced chain life and much shorter intervals until I had to re-lubricate. To a lesser degree I experienced the same issues with degreaser and automatic cleaning devices that contain pulley-like brushes.
One really can do too much cleaning.