How do you determine the right chain length
I've got 108 links on there now - which is different than other chains I've had on there - all put on by mechanics. I have new chain that I know is way to long, and I'm wondering how many links I should take off. The chain I have on there works good enough, but the pulley grinds a bit (shimano 105 at it's limit with a 12-27 cassette). 30/42/52 rings up front. Chain stay is 410cm.
Would a longer/shorter chain help prevent the occasional grinding pulley?
Any advice appreciated!