The Fox River Trail is a great limestone trail, very heavily used around the towns of St. Charles, Geneva and Batavia on the weekends (watch out for strolling families!). I've ridden it from St. Charles to the south but not north of St. Charles. It changes into another trail name as you go north and you can actually ride all the way to the Wisconsin border if you want - this stretch is supposed to be less crowded. Once you get away from the populated areas you can build up your speed a bit. I don't know where Pheasant Run is, so I can't tell you how far it is but you can MapQuest it if you know the street address. It's very scenic with the river on your side as you ride. A map is available at http://www.co.kane.il.us/Forest/frtrail.htm. You could also consider the Great Western Trail leaving from Leroy Oaks Park in St. Charles and travelling west. It's a rails-to-trails limestone path and also very pretty. Welcome to Chicagoland!