I love draggng up old threads... If you're doing any sort of riding with hills (or headwinds) gears absolutely help on a trail-a-bike. I recently bought a Tout Terrain Streamliner and am writing a review for TheBikeDads. The streamliner comes with 9 speeds. The only gears that really matter (to me anywyas) are the 2-3 lowest gears when we're on a climb because here we're either climbing or descending. There's very little intermediate fast-rolling singletrack where we'd want to pedal. I used to have a fixed gear hand-me-down, and when climbing I'd only get power contribution from my son every 2-2.5 pedal revolutions, but now I get it the whole climb and it's absolutely noticable and appreicated and I can totally tell when he lets off the gas. And he's 4.5. And the suspension is awesome. We can totaly blast through rock gardens and as long as he keeps his pedals level, he's like, "What bumps?"