In a way you cant even call them big anymore because a CRF450x only weighs 240 pounds. As far as trail riding alone, I always try and get someone to come along but most retired men prefer to go out twice a year and watch TV the rest of the time. So If that the case I just carry a weapon, cell phone, GPS, map, water, tools/tire patch and make sure I'm not sick and in good health (work out every other day). Then give a sincere prayer asking the Lord to come along. I figure if I take reasonable precautions and the good Lord wants to let me die the desert is as good a place as any.
My alone trips are usually 5-7 mile circles so I am never more then 10 miles from home or the main road. The desert isen't like the forest and has many land marks. But its happened to me. Before I had gotten my RM100 tuned properly for trail use I was still running race plugs which are designed to be burned wide open throttle, so a spark plug fouled on me without a spare 7 miles in the desert in 80 degree heat and rising (9am). Since the RM100 only weighs 145 pounds it was almost easier to walk it out then walk alone except crossing 3 canyons down and up hill. But I made it out and when I reached the corner store I bought and drank 1 gallon of water before walking the rest of the way home.