The park dh 1 dummy hub is perfect for chain cleaning and transport it easily slides into the rear dropouts to replace the rear wheel the unique design allows shifting when the dh 1 is installed and works with thru axel frames up to 12mm and open dropout this park tool dummysleeping hub is compatible with all derailleur and 18rsquorsquo chains park dh 1 dummy hub features fits into a frames rear dropout to replace the rear wheel unique design allows shifting with the dh