How to Size a Bicycle Chain
Why Bicycles Stack Exchange recommends it
Bicycles Stack Exchange answerers point people to it when a new chain is too long or was sized wrongly, for example after a derailleur change or chain skipping.
Recommended by 2 people across 2 different months, 2019 to 2020.
What it is
A Park Tool tutorial on cutting a new bicycle chain to the right length. It covers sizing against the old chain, the largest cog and largest chainring method, and exceptions such as rear suspension and chain guides.
What people said
Recommends Argenti Apparatus · 2020-06 · Bicycles Stack Exchange · on “I think I have installed my new rear deraileur incorrectly, can anyone give me some advice”
That's not the correct way to size a chain. The chain needs to be long enough to get on the largest chainring and rear sprocket. See these instructions [this video] . Shimano has a slightly different procedure for single chainring setups.
Recommends Tude Productions · 2020-12 · Bicycles Stack Exchange · on “Chain skipping on upper pulley of rear derailleur”
New chains are not sized out of the box (i.e. they are usually several links too long). Part of installing a new chain is to size it by removing links prior to installing it to match the length of the old chain. I suspect you may have mis-sized the chain. Otherwise it is possible that your jockey wheel on the derailleur is worn. Those can also be replaced individually. I am not expert on sizing a chain, but Calvin is so here you go: Also, no shame in going to a LBS to have them look at the drivetrain, size the chain, adjust the B screw as they do it day in and day out plus it requires a few special tools. You probably could get all of that fixed up for $20-$30 plus parts if any are required.
Cites Maarten -Monica for president · 2019-12 · Bicycles Stack Exchange · on “I want to replace 52/36 chainrings with 50/34 chainrings on a Praxis Works”
You should be able to do it with your current cranks as long as you get chainrings with the correct BCD (Bolt Center Distance). How to measure your current BCD: [LINK] You might want to adjust your front derailleur so that it's a few mm more towards the bottom bracket (positioned slightly lower on the seat tube than it was originally), in order to compensate for the slightly smaller diameter of the new chain rings. How to check if chain length is correct: The chain might need to be shortened by 2 links to get perfect chain length but it should work with current chain length (since the difference in teeth between original and new chain rings is only 2 teeth). How to adjust front derailleur (i