SHOCK ABSORPTION: Preventing the rebound no matter in rugged, bumpy, or rough roads and making your riding comfortable. LOW WIND RESISTANCE: Traditional bicycle rim always bring some uncertain volume of wind resistance when  . The bike will start decelerating immediately if you stop pedaling. "UNI WHEEL" is designed according to the Centrifugal Force and windmill theory. While riding, "UNI WHEEL" will keep cycling and moving on even the pedaling stopped and not decelerates right away. When in riding, it will be faster, easier and also accelerate the speed. VARIOUS COLORS: Color your bike with more colors to choose from and more combinations to make.FRONT FOR DISK BRAKE & REAR FOR V-BRAKESIZE: 26"x1.5"~2.35" (559x18) MATERIAL: ALUMINUM MAGNESIUM ALLOY ASSEMBLY: BEARING AXLE: FRONT: M9X100x108 W/Q.R. REAR: M10x130X140 6SP FREEWHEEL W/Q.R. M10x135X145 7SP FREEWHEEL W/Q.R. M10x135X145 8SP FREEWHEEL W/Q.R. 3/8X130x180 6SP FREEWHEEL NUT TYPE 3/8X135X185 7SP FREEWHEEL NUT TYPE 3/8X135X185 8SP FREEWHEEL NUT TYPE HUB: 6 HOLES IN FRONT HUB FOR DISK PLATE ASSEMBLY COLOR: POWDER COATING RED, YELLOW, BLUE, BLACK, SILVER / C Weight: front 1250g & rear 1400g FOR M.T.B. & A.T.B. & CITY & TREKKING