My commute is just under 12 miles one way. With my conditions it takes about 45 minutes in the morning and 60 in the afternoon

My new bikes are stuck with an old beater engine. Poor bikes!

My ride 30km one way (17 miles?) and it takes me just a little over an hour, maybe like an 1hr and 5min or so. It's totally flat the whole way, so I suspect it would take me longer if I had some decent hills.

are any big hills involved.. Have you figured your average rate of speed... Mine is like 16-18 on the flats.. Depending on my motivation. My one way commute was 27 miles.. WIth a couple steep grades involved... I did it anywhere from 1.5 to2.5 hours..

My route is about 8 going in, 9 going home. Going in is early and faster (32-40 min), going home is generally slower because of more lights, traffic and people (40-50 min).