I'm planning on going from a 52T chainring to a 60T on my folding bike (with no front derailleur to contend with) and my question is this; How much longer chain do you think I'll need. I'm pretty new to bike mechanics. My uneducated guess would be adding 4 more links cause there will be 8 more teeth but only half the chainring is actually "engaged" by the chain. Or is there other factors I'm missing. Or is this something to just play by ear?
New chains will almost always have a few extra links that can be removed to size the chain down to the right size. My guess would be 6 links more (4 more engaged + longer circumference) but that is pretty irrelevant. Use the same method for sizing the chain as you would with the 52t. Wrap chain around biggest rear sprocket, wrap around chainring (skipping RD), bring chain together, add one link, run it through the RD and connect the chain.