First time I've seen this old post, good tooling ideas. I use a 5 compartment backpack which i'm used to from years of other activities. All the usual stuff + a collapsible plastic bottle for mixing fuel(my wife rides a 4 stroke & great mileage),first aid kit, ace bandage, cell phone, and balloons for markers in case someone gets separated or I loose them(lost my wife for over an hour ONCE). If you get lost back track to the balloon and stay put.
Last June I was riding with 2 of my grown sons and found a cheap fanny pack on the trail. I had a sd card, usb cables, a charger, sunglasses, a lighter, a glass weed pipe, a couple chewed up baggies with green leafy residue, a map for a 5 day ride here in northern Mi. and a motel key room #8. We thought about taking it to the motel 12 miles cross country away but left it hanging on a branch in plain view in case they were looking for it.
I'm more sinner than saint and I'll never be a judge but the more I thought about it, I don't want to meet a buzzed up quad driver on a tight corner at 40 mph either. Later at home we were popping bottles wondering how some folks survive. Maybe it's because of the people with tools in thier tool kit.
