Allen Sports Bicycle Carrier Adaptor Bar is a go-to rack accessory for non-conventional bike frames. The Allen adaptor bad adds a top tube to non-conventional bicycle frames. The top tube allows for transportation of your Bike to your intended destination. An internal spring maintains constant tension to securely transport. The adaptor bar quickly attaches to wide range of frame styles and can be used as you change your ride. Rest assured with plastic coated hooks that protect your bikes finish.