The front-to-rear length of the outside dimension of the round-hole rack is 27 7/8”. I have the SC213A-R900UB chassis with the MCP-290-00053-0N rail set. Because of the round screw holes on the rack, I have to use the adapters, but the rails are too long for my rack. Does the MCP-290-00053-0N rail support racks with front-to-rear depth between 26.5" to 36.4"?
The adapter itself is 0.8” long. The total rail length with two adapters will be 28.1”, which is longer than your rack. Please use MCP-290-00058-0N 19”-26.6” rail set.