• Made of high quality steel material, high strength, wear-resistant and durable
• Hollow technology can easily reduce weight and make riding easier
• With nickel-chromium treatment surface, prevent flywheel from rusting, with longer service life
• Outstanding performance, to achieve the ultimate riding experience

Specifications:

• Speed: 9 speed
• Material: steel 
• Gear ratio: 11-13-16-20-24-28-32-36-40T