Here is my first attempt at the route. Trying to do this trip in 2 weeks, which is a bit tight, but just about doable, riding around 100km a day, with some days for sightseeing.
I’ve put clickable links to some of the places that we’ll stay.
Day 1 : Leave London (London -> Bangkok -> Mandalay)
Day 2 : Arrive Mandalay
Day 3 : Mandalay -> Myingyan (100km)
Day 4 : Myingyan -> Bagan (75km)
Day 5 : sight seeing in Bagan
Day 6 : Bagan -> Yenangyaung (100km)
Day 7 : Yenangyaung -> Taungdwingyi (110km)
Day 8 : Taungdwingyi -> Aunglan/Thayet (100km)
Will need to get boat over river from Aunglan to Thayet
Day 9 : Thayet -> Pyay (90km)
Day 10 : Pyay -> Myanaung (110km)
Day 11 : Myanaung -> Hinthada (110km)
Day 12 : Hinthada -> Nyaungdon (100km)
Day 13 : Nyaungdon -> Yangon (80km)
Day 14 : Sightseeing in Yangon
Day 15 : Fly Yangon -> Bangkok -> London
Total : 950km + 50km faffing about getting lost = 1000km!!!