I don't know why but I'm stuck at this 20km/h margin, I just can't get faster I need to find a short route to do. Commute to uni is 20 minutes but now everything is online except the odd lab every other month. I still don't know how i would do a 200km audax, 173km is my record and that was painful, I thought I was going to have a breakdown past the 110km mark- but to note-I did it unprepared-a big jump from 108km to 173km and a route the was way more hilly. Since then did the 125km in the Chilterns. But now think it's too cold to be doing 100km rides.My commutes were 40-45 mins which you’ll work out is 24-27km/h. Faster than my audax pacing. But they are not long rides, and there was a hot shower at the end, so I could afford to push a higher pace. Commutes or regular short rides on a route you do regularly are a great way to test and improve your fitness.