Your hands take a beating, so double bar tape or a carbon bar that dampens vibration is important. The cobblestones can be brutal, this is not neatly laid city cobblestones, but they are basically farm tracks. Forget about having anything attached to your bike like saddlebags, mine lasted about 100m. Also make sure everything is tight, a friend's cassette came loose on the cobbles. Don't worry about drink bottles, every cobble section is littered with lost bottles. So thirst is the least of your problems. (you will want to take 500ml bottles, the big ones are too heavy)
And ride out all the pavé right through the middle so that you never have to go back another year to do it again properly. Once in a lifetime suffices, it really is not pleasant. For the same reason, buy all the souvenirs you can get. I think in Arenberg there was a perfectly smooth bike path next to the cobbles. Don't do it. That's not what you are there for. And don't use a mountain bike. Stadium finish in Roubaix is fantastic though.
For tires, I used 28's with latex tubes for better pinch resistance, but now I have tubeless, and I would also trust them to do the job.
Lille is a nice place to stay, nicer than Roubaix.
Last edited by AfromD on Sat Apr 01, 2017 8:30 pm, edited 3 times in total.