Yes. I am shocked that you are asking that question. Please do not think that 1 inch would be a performance improvement over 1-1/4 in any way.
I consider calculating pipe size the hardest part, not the actual work. I really appreciate all your posts Reach. I'm going with 1/1/4". I already have a 300' roll of 1 1/4". I bought 200 PSI CTS. Did I make a mistake? Should I have purchased IPS? I think the inside dimensions are the same, but the walls are a little thicker on the IPS.