My son (4 y 9 mo old) rides on the Adams Shifter 7. In my opinion, it is NOT a gimmick. He is learning to shift effectively and efficiently, given the surface (we ride both on and off road) and slope of the road ahead. He shifts to the appropriate gear given the speed we are traveling. He also rests when he needs to. I do know, however, his biking skill is better than most his age. Just after his 4th birthday he asked me to take his training wheels off. He rarely crashes - that day, or since. He has also done hundreds of miles, both on and off road, on a non-pedaling Instep Hitchhiker (similar to Adams). Either way, to say it is a gimmick is like a single-speeder calling your multi-geared bike a gimmick. For some it works, for others it doesn't.
Technically speaking, it has a 44 t front ring and a 14 - 28 cassette. With a 20" tire, this yields a gear inch range of 31.4 - 62.9. This is roughly equivalent to the range on my Surly CrossCheck from the middle chain ring (36t)/largest cog (32t) to the middle ring/middle cog (16t). In these gears I have an effective cadence from approx. 5 - 20 mph, which is plenty of range for when I'm riding with a trail-a-bike. We've ridden some pretty steep paved hills, as well as technical singletrack (Banner Forest, Capitol Forest, and Lake Sawyer are our favorites).
Last edited by hopperja; 02-20-07 at 11:56 PM.