SPECIFICATIONSApplicable People: MaleBike Suspension Types: BidirectionalBraking System: Double Disc BrakeBrand Name: NONEFork Material: STEELFrame Material: aluminumHigh-concerned chemical: noneOrigin: Mainland ChinaRim Material: STEELType: Folding BicycleWheel Size: 18Inches 450mm Bike Type Road Bike Age Range (Description) Adult Number of Speeds 21 Color Black and White Wheel Size 680 Millimeters Frame Material Alloy Steel Suspension Type Rigid Included Components Pedals, assembly tools, reflector, and pump Size 49cm This road bike features a 21-speed gear shifting system and is available in sturdy alloy steel frames of 49cm and 54cm sizes. It is an excellent choice for both beginners and intermediate riders, suitable for competition with its improved handling, lightweight design, and stylish appearance. The bike is equipped with a Mechanical Disc Brake System, which offers long-lasting and stronger braking power compared to traditional V-brake systems. It comes with 700C x 28C tires, providing a classic look and double wall rims. The anti-skid design on both sides enhances grip and confidence during high-speed turns. The 700C wheels offer low rolling resistance, allowing for easier navigation over potholes, bumps, and other obstacles on roads or trails. The 21-speed shifting system, complete with shift levers, front derailleur, and rear derailleur, ensures smooth and durable gear changes, making your ride more efficient and enjoyable. The bike is available in two frame sizes: 49cm, suitable for riders between 54 to 5'7, and 54cm, suitable for riders between 58 to 6'1. Assembly is straightforward, with 85% of the bike pre-assembled. You only need to install the front wheel, handlebar, pedals, seat, and inflate the tires. Basic assembly tools and an installation manual are included in the bike box. An assembly instruction video is also available to help you assemble your bike in approximately 15-20 minutes.