Sorry to resurrect this older thread, but I am researching old 1981-era cheng shin tires for a build and this thread is a fantastic discovery for me. I am looking for this cheng shin tire pattern with the two lines/cuts/ridges above the semi-circle knotch on the innermost knobs. Three questions: 1) Were the "two-ridge" tires in this tread pattern made in both 1.75 and 2.125?, 2)If only made in 1.75 (but can fit a 2.125) as imprinted on the tire, did the 1.75 appear fatter and more like a 2.125 anyway?, and 3) Where/who may be my best sources for these now? Many thanks for any help.