Shimano Disc Brake Rotor RT-MT900 Size:180mm The down tube size is

The down tube size is limited to 75mm diameter (3″)

Material: Aluminium construction

Lightweight internal hem elastic with silicone gripper

It also has a handle integrated into the saddle so you can guide while they ride and tool-free training wheels that are super easy to install and remove

<dtw>Ksyrium has always represented the best in aluminum wheel technology

Shimano Disc Brake Rotor RT-MT900 Size:180mm The down tube size isDescription XTR and Dura Ace RT MT900 Ice Tech rotors providing consistent braking performance through energy control, using revolutionary stainless steel alloy 3 layer sandwich construction that manages heat while riding The clad steel alloy steel rotor construction allows heat generated from braking to radiate quickly through the aluminium core achieving surface temperature drops of around 50 deg C. When used with Ice Tech pads surface temperatures