ACCEPTABLE SIZE FOR A BATHROOM SINK DRAIN PIPE

Due to space limitations and needing to cross a joist near its end, I want to use a 1-1/4" ABS drain pipe for a simple bathroom sink drain pipe. There is no toilet or shower connected to this drain. I know that 1-1/2" ABS is typically used. Because there will be no solids like from a kitchen sink, is there any reason that 1-1/4" is not acceptable for this application? I want to take out as little of the joist as possible and recognize that piercing it near the end minimizes the loss of...

ACCEPTABLE SIZE FOR A BATHROOM SINK DRAIN PIPE