From Lowbrow Customs: Mount your solo seat easily with these weld-on solo seat spring mounts. Made of 1018 cold rolled steel for easy welding, they are 1" diameter with a 3/8" shaft for the spring to sit over. They are coped at 1" to fit standard size frame tubing, but can easily be enlarged to fit larger 1 1/4" tube if necessary. They come with a pair of 1/8" thick leather washers to keep your springs from squeaking, as well as two spring cotter pins to hold your springs in place on the cross-drilled shafts. Price is for a set of two mounts, spring cotter pins and leather washers.