We created the prototype offset sprocket using shark teeths from a great white shark and stuck them to a ring of metal. The result was so good we decided to built the identical sprocket from galvanised metal. With this offset sprocket you can use extra thick wheels on our Ruff Frames and this might prevent falling over with your bike. At least we hope so.The offset sprocket lets you use 100 mm rims on you bike. Without the sprocket the chain would either grind on the tire or frame. So if you would like to use a 100 mm rim with our Ruff Frame (or any other frame) we would recommend to use our Offset Sprocket.