Quote: "Formerly posted by runawayronin: I'm using Muc-Off. I bought a set off CRC during a sale. Compared to WD-40 it is bit of an investment but it is a lot easier than taking an old toothbrush to your drivetrain."
I find it easier to reuse old toothbrush before disposal.
Quote: "Formerly posted by alma788: Hey, I think RP7 will work best. I have already used it for my bike chain and also after using it you should tighten the bike chain also. If you want to know more about how to tighten bike chain then check out https://biketestreviews.com/how-to-tighten-bike-chain/"
Multi-speed bicycles come with RD for taking up any chain slack.