Chains

People fresh from the tech industry or their home basement lab but new to bicycles are always trying to find a better alternative to the chain. For derailer-equipped bikes without removable seat stays—normal bikes, in other words—the humble oiled chain, around since 1885 and perfected by Sedis in the '70s, still rules the drivetrain. If your chain squeaks, lube it. If it gets gunky, clean it with Simple Green; let it dry, and lube it.  We're transitioning to "greener" (not petroleum-based) chain lubes from Mountainflow (brand), after years of loving Boeing's T-9. When it wears out, replace it.

Here's a gear calculator chart.