Okay, kids grow up quickly, but when they're in the age between 5-8, that BMX bike with 20" sized wheels is simply too big for them. They'll lose interest because they can't handle the bike because of its weight and size. There are solutions, like the HARO 116 which is based on the geometry of what the older riders use and looks the part. Visit a HARO dealer near you and get advised.
HARO 116:-Hi-ten 16" freestyle frame
-1 1/8" threadless, Chromoly steer tube fork
-Hi-ten 7" bars with Haro alloy front load stem
-3-piece chromoly 8-spline 135mm cranks with loose ball USA BB
-25/9 gearing
-Grips: Haro Mini Stripe Grips
-Haro MS4 tires 16 x 2.0" front and rear
-Haro padded one piece seat with built-in alloy post
Colors: Gloss Black, Matte Silver.
MSRP: $309.99 (USA)
WEIGHT: 23.20 lbs
More info at www.harobikes.com