From Grenoble, we took the bicycle route V63 (that starts in Annecy) following the river Isère to where it joins the river Rhône, and then a few more kilometers on ViaRhôna to Valence. We rode 122.10km in 6h52mins (average 17.7kph, max 33.9kph), with 983m of ascent and 1077m of descent. The route was surprisingly hilly given that it followed the river most of the way. We had perfect weather: it was sunny but a bit chilly in the morning at 7:45am. when we started (+12C) but got quite warm when the sun got higher and rest of the clouds evaporated. Again we had a nice tailwind on ViaRhôna.
From the junction of the two rivers we had eight more kilometers to ride in about 45 minutes. When approaching Valence we took a wrong turn — or rather tried our luck with bike paths still under construction — and had to turn back. We still caught our train with a 3-minute margin. What a great ride we had! It is so easy to get completely addicted to bike touring.