Joined: Jun 2011
Posts: 1,180
Likes: 0
From: Sunnyvale, California
Bikes: Bridgestone RB-1, 600, T700, MB-6 w/ Dirt Drops, MB-Zip, Bianchi Limited, Nashbar Hounder
I can't really comment on chain rings, although steel rings are making a comeback! Why? Because thinner chains require thinner rings and so steel is still strong when thin.
As for chain widths:
9.0 - 9.5mm - single speed/BMX chains
7.4 - 7.6mm - 5/6 spd
7.1 - 7.4mm - 6/7/8 spd
6.6 - 6.9mm - 9spd
5.9 - 6.1mm - 10spd
5.5mm - 11spd