Biking in Prague

what sort of tour, is it to see the sights in the main city or to do countryside visits.The main tourist areas are pedestrianised and though i have seen a few cyclists around and there are companies that offer tours BUT I certainly would be extreemly wary of cycling in the Old Town area, Wenseslas square becaise of the amount of foot traffic there, cycling on Charles Bridge would be impossible because of the crowds apart from the very early or late hours.
There are lots of countryside cycling routes outside of the city and The Uneticky pivovar a few miles to the north of the city is a popular stopping off point for many cyclists,so much so they even sell their own branded cycling tops. there are places to hire bikes if you want to get out on your own

Actually all wheeled vehicles are prohibited on the bridge and generally not a good idea in old town square.

There are numerous bike companies. City Bikes offers rentals and tours. Self guided to Karlstejn Castle for ex.
https://www.citybike-prague.com/
https://www.citybike-prague.com/bike-tours