I have a buddy that owns a bike shop,old school shop, he doesn't have an on-line connection. He still uses catalogs,I just look up what I want. They all give the tensile ? strength and I pick one at the top. The last one(RK racing chain) came in 110 links for my stock 45/15 witch I replaced at the same time. But I have purchased chains at 120 links with different gearing and just cut them to size.