Agree with the advices on having fresh tires. I had an accident last summer which might have been avoided with a new front tire on the bike. I panic braked because a wasp caught in my helmet stung me. The front wheel blocked (No ABS and beginners error - I know) and I crashed. The front tire...
When in Vienna: Do not miss the area North of 19th District/Döbling and see the wineyards in the hilly landscape with the narrow roads and the perfect view over the city. Stop and have a meal at one of the Heurigers. Tasty and traditional Austrian. Skip the Heuriger, if you prefer vegan ;-) Enjoy!