GMC Denali Road Boys Bike, 24-Inch Best suited for smaller riders. Age Range: 9 - 12 years 21-speed road bike features a lightweight aluminum frame Alloy calipers and alloy brake levers High-profile alloy Vitesse racing rims Shimano derailleur and Shimano Revo shifts makes it easy to change gears quickly and smoothly Frame Size- 14.75inches(measured center to center) Effective Top Tube- 18.75inchesStand Over Clearance at the center of the top tube- 26.75inches