A further thought: if you are coming in from the north-west you have to go through St Denis which is fairly grim, but then you have to get past La Défense and the periférique which I suspect would be particularly. I'm sure there must be a way through but I suspect you need a route planner aimed more specifically at cyclists - or maps of cycle routes in Paris. Here are some links that might be useful:
http://www.geovelo.fr/
http://www.parisavelo.net/new_carte_pistes_cyclables.pdf ( only the city of Paris)
http://www.paris.fr/pratique/deplac...-amenagements/rub_9931_stand_64244_port_24784 ( only the city of Paris)
http://voiescyclables.free.fr/idf1.html (voies cyclables Île de France)
http://www.iledefrance.fr/lactualit...ables-dile-de-france-la-carte-2010-est-parue/ (link to the map of cycleways in the Île de France)
For tricky bits like La Défense, Google Streetview can be invaluable.
http://www.geovelo.fr/
http://www.parisavelo.net/new_carte_pistes_cyclables.pdf ( only the city of Paris)
http://www.paris.fr/pratique/deplac...-amenagements/rub_9931_stand_64244_port_24784 ( only the city of Paris)
http://voiescyclables.free.fr/idf1.html (voies cyclables Île de France)
http://www.iledefrance.fr/lactualit...ables-dile-de-france-la-carte-2010-est-parue/ (link to the map of cycleways in the Île de France)
For tricky bits like La Défense, Google Streetview can be invaluable.