Just the other day, I was talking to an acquaintance about high-tech bicycle gear. Specifically we got into a conversation about portable tire pumps, the little ratchet type pumps which are lightweight and you can take with you in case you get a flat tire on the road, or on a trail the middle of nowhere. They only weigh a few ounces, not even one whole pound. But they sure come in handy if you get a flat tire, patch that tire, and they need to pump your tire back up to continue your journey.
After I finished that conversation, I realized how much I love to go out and mountain bike ride in the trails near where I live. Unfortunately out here in California we've had a few fires, and one of my favorite trails has literally been burned to the ground, it smells like you are riding through a burned out barbecue, it's ugly, and it looks like hell. Even though one doesn't know what hell looks like, I think you might say the same thing if you saw it this way.
One of the most interesting things I like to do when I travel is to rent a mountain bike, or borrow one from a friend and find out what sort of trails they have near them, trails I might explore on a mountain bike. In fact, there's a very good book about the mountain bike trails in the Philadelphia area. This is a Falcon Map Guidebook, it is a book I own, and one I'd like to recommend you. The name of the book is;
“Mountain Biking the Greater Philadelphia Area – A Guide to the Delaware Valley's Greatest Off-Road Bicycle Rides,” by Bob D' Antonio, Falcon Press, Guilford, CT, 2004, 223 pages, ISBN: 0-7627-2806-X.
This book comes with all the information you need. It tells you where each trailhead is found, how to get there, where to park, the number of hills, number of miles, and suggestions of gear you might need and the time it might take to complete based on your abilities and physical strength. Each trail also shows an elevation chart just like they do in the Tour de France stages, where you can look and see on a graph how many feet in elevation you go up and down as you travel.
If you're going to do any type of mountain biking in the greater Philadelphia area, then you need to get this book as well. It's not very expensive, but it is a must have. Please consider all this and think on it.