I have a acme, 30-1001 which I'm trying to replace.
Dave Sr. from SWISCO responded:
February 4, 2015
Thanks for posting. The 23-161 is a heavy duty trolley for doors weighing 100 pounds and has 7/8" diameter wheels. The 23-189, on the other hand, is for a standard weight door and has 3/4" diameter wheels. Which is closer to what you need?