Objective: cadence 80-90 for the first 100 km, then 65-70 for the last 25 km or so. No one else turned up for the group ride, so I did my own thing. I tried to keep the cadence 80-90 and heart rate 145-155 (is that more or less "tempo" for me?). Then I hit a rough patch of road for ~3.5-4 km and my chain broke. That was at the 96 km mark. I didn't have a quick link and I couldn't fix it with the tools I did have, so had to walk ~ 7km to a bike shop. Got a new Ultegra chain and Ultegra cassette. That set me back EUR 129.90, so if you see a spike in my heart rate around 4 p.m., you'll know why! Then I rode the last 30 or so km home, but was a bit too bummed out to do the 65-70 cadence (it also took a few minutes for the legs to warm up again after the pitstop at the bike shop). I think I managed to keep it at 80-90 and maintain the heart rate at 145-155 though.