Charles Ramsey
74 58
74mm to 58mm 56mm chainring adapter made out of a computer hard drive. The hard drive platter is 2mm thick the spacers are 4mm thick the chainring is a sugino with dual 58mm 56mm bolt holes. A first I tried to use a 1.2mm thick stainless pizza cutter it bent while I was filing the central hole. You need to use washers on the chainring nuts or the notches will dig into the aluminum.
74 58
74mm to 58mm 56mm chainring adapter made out of a computer hard drive. The hard drive platter is 2mm thick the spacers are 4mm thick the chainring is a sugino with dual 58mm 56mm bolt holes. A first I tried to use a 1.2mm thick stainless pizza cutter it bent while I was filing the central hole. You need to use washers on the chainring nuts or the notches will dig into the aluminum.