Sounds great! I was thinking of doing the same kind of thing this spring/summer in the Zürich area too... Maybe also during a weeknight after work, if we can find a route that doesn't intersect with too many drivers commuting home.

You can always post a ride with mileage, route, and approximate speed as Johanna suggested and see how many people show up... I'll be there if I can, at least as long as it's not around Lake Zürich (too flat and too much traffic for my pref).

This will be fun!