We took the 4-hour "City Bike Tour Ljubljana" with our guide, Andrej. Andrej was fabulous: filled with informative, historical, and humorous details. The ride allowed us to see many parts of Ljubljana in a short time, and Andrej tied it all together. The ride was not too difficult (we are seniors). The lunch stop was perfect (Slovenian charcuterie, plus a pour of local wine): enough to eat, water to drink, and a convenient WC.
We recommend this tour (and Andrej) without reservation. We could not hope for a better experience.