The MX20 will suit 6 to 8 year olds. At this age it's worth having gears, but not too many, so it comes with 6 speeds operated by a simple twistgrip. Now at least they can keep up with you. Front suspension also arrives. You also get V-brakes with reach adjustable brake levers. The frame is still nice and light, with a low crossbar and two simple vibrant colours. You might also want to consider the Dimension 20" which is a little more lightweight with no supspension.
Dark Blue or Yellow