Check the listing for details. Rear Wheel Hub Adapter CNC Fully Made for Spoke Bike Wheel-Gas Motorized Bicycle. Color: Silver, Condition: New. Listed at 36.88 USD. Package include: 1pc Racing Rear Hub Adapter (1"/1.25"/1.5" for choice) 1. Compatible with our 3+6+9 hole multifunctional sprocket CDHPOWER High Performance 32T/36T/40T/56T Sprocket-Gas Engine Motorized Bicycle 2. Compatible with our 36T/40T/44T/52T cnc sprocket CDHPOWER Aluminum 36T/40T/44T/52T Sprocket CNC Made-Gas Engine Motorized Bicycle 3. Do not works with 9 hole and 6 hole sprocket. 4. Package include only adapter 1", not include sprocket 1.0 inch Rear Hub Adapter 1. 1" Rear Hub of SPOKE WHEEL BIKE with a diameter of 1."to 1.02" 2. Does not works with 9 hole and 6 hole sprocket3. Only fit spoke wheel bicycle;4. 2pcs screw 12.9 Grade/W3/8-16X1" , 3pcs screw 10.9 Grade/W5/16-18X1";5. Adapter is a durable aluminum unit fully cnc machine made that provides fast and easy installation;6. Worked well on gas motor kit 48cc/50cc/66cc/80cc gas motorized bicycle;7. Please note: The bigger three allen bolts diameter is 10mm; 1.25 inch Rear Hub Adapter 1. 1.25"Rear Hub of SPOKE WHEEL BIKE with a diameter of 1.21"to 1.25" 2. Does not works with 9 hole and 6 hole sprocket3. Only fit spoke wheel bicycle;4. 2pcs screw 12.9 Grade/W3/8-16X1" , 3pcs screw 10.9 Grade/W5/16-18X1";5. Adapter is a durable aluminum unit fully cnc machine made that provides fast and easy installation;6. Worked well on gas motor kit 48cc/50cc/66cc/80cc gas motorized bicycle;7. Please note: The bigger three allen bolts diameter is 10mm; 1.5 inch Rear Hub Adapter 1. 1.5" Rear Hub of SPOKE WHEEL BIKE with a diameter of 1.52-1.528" 2. Does not works with 9 hole and 6 hole sprocket3. Only fit spoke wheel bicycle;4. 2pcs screw 12.9 Grade/W3/8-16X1" , 3pcs screw 10.9 Grade/W5/16-18X1";5. Adapter is a durable aluminum unit fully cnc machine made that provides fast and easy installation;6. Worked well on gas motor kit 48cc/50cc/66cc/80cc gas motorized bicycle;7. Please note: The bigger three allen bolts diameter is 10mm;