I suggest you stay in Levis which is on the south shore of the St Laurence river and take the ferry to Quebec city. You arrive in "old Quebec" where the action is.
There is a nice litte motel called Motel Etchemin on rte 138, a few minnutes from the ferry.
Leaving your car/bike at the motel and in the parking lot near the ferry is safe. I can't find the tel number but I am sure you will find it.

Enjoy your stay.

Robert (2007 K2007GT)