Going Up Four Inch Curbs
My physical therapists taught me how to go up a six inch curb with my wheelchair. First you have to know how to do a wheelie. Then, (with someone spotting you from behind) roll toward the curb and do a short wheelie that raises the front casters just above the curb, followed by leaning forward and pressing forward on your big wheels when your tires touch the curb. This all takes less than a second. However, it takes practice to perfect the timing.
Make certain you start out learning on a two inch curb. When you've mastered that, you can graduate to a four inch curb. Then you can tackle the six inch curbs. Once you have learned the technique, your curb jumping maneuver will be as smooth as butter.
But, I get out of practice if I don't go up curbs frequently. So, I made my own four inch practice curb in my basement. I bought a 3/4 inch piece of plywood four feet long and four feet wide. I also bought two, eight foot long two by four inch pieces of wood. I already had some long wood screws which I used to fasten the two-by-fours to the plywood with the result you see here. I put a hole in the middle of each side of the platform so that I can lift it.
To drop down from a curb, I do a wheelie and get close to the edge of the curb with my big wheels. Then, I gently push forward, over the edge of the curb and drop to the floor - still in a wheelie. I immediately roll carefully back against the platform (still in a wheelie) which puts me in a very stable position that is easy to maintain. When I was able to consistently drop down and roll back into a stable wheelie without going forward more than a few inches - I discovered I can actually go down a set of stairs!
Going up stairs is another matter... I'll leave that to some athletic young stud to figure out.