Cycling is not really popular in Mons, but there are times (especially in the warm summer days), I've seen few people ride their bikes. Usually during the day some kids from school cycling around town, with their teachers guided and showed them some rules on the street.
Cycling is very safe in Mons because there are bike lanes in bigger roads and mostly empty. Not like in Amsterdam, which is very hectic.
Me and Prince Charming think having a bike is not a good investment because just like others, we mostly walk around Mons. But since 2011, like in many big cities in Europe, the local government gives the opportunity for the Montois and visitors to rent a bike, located around the train station.