This is a completely subjective topic that no one can answer over the internet. It completely depends on what YOU like. Some people like -1/+1, others swear -1/+2, and others still like just +1 or +2 on the back. YOU have to try different combinations to see what YOU like in the riding conditions that YOU do and that make sense for YOU and YOUR bike.
Same goes with a 520 or 525 conversion. If you're that conflicted about it, stick with the 525 stock size. Aluminum on the rear if you don't mind changing sprockets more often. Steel if you want to put it on and basically forget about it.
Same goes with a 520 or 525 conversion. If you're that conflicted about it, stick with the 525 stock size. Aluminum on the rear if you don't mind changing sprockets more often. Steel if you want to put it on and basically forget about it.