Barely used, includes custom comfort seat For kids making the jump from a push-bike to a “big kid” bike, the Jr Viper fits the bill. This bike has all the features you’d expect in a BMX bike, like a bomber steel frame and fork, sturdy wheels, and beefy tires. Then we added a few extras to help smaller riders enjoy neighborhood jaunts even more: a chain guard to protect skin and clothing, a rear hand brake plus a coaster brake to help ease the transition to braking with their hands, plus super short 140mm cranks sized just right for kids. This model fits riders 44”-54” tall, aged approximately 5-9 years old.