This is a good set of "exercise wheels". They are strong enough to hold small children upright until they are confident enough to take them off. Of course, they're not heavy enough to climb hills or anything like that, but they're great for training on a flat surface. The instructions could be a bit more detailed. but they are clear enough. I see a lot of reviewers have broken seat post clamps. The instructions clearly state 12-13 ft.lbs so they don't break. I know not everyone has a torque wrench. I installed everything just tightened the screws. Then I rotated the axle until the wheels were about 2 inches off the ground and tightened the bolts evenly. Once they were almost tight, I tightened the axle and tightened until I could no longer turn them by hand, then tightened each half a turn. I know the stop pins for the tires seem crappy, but we haven't seen any trouble keeping them. My son and grandson have been playing it for a few days now and I've never had to pull it up. I think that means they don't have much ground contact, which is a good sign that they already have a good balance. However, overall I feel a lot better after adding them for my grandson. As for my own kids, I would just walk over them in the field and watch them fall over and over again until they got the hang of it. (can explain something) For me it's the same as for her. One more note. I can see in the photos that the axle is bent forward. Not a good idea. If they bite the ground, the bike might bounce a bit in the air. I turned mine back on to be safe.