The substance ii the substance ii takes all the features from its older brother plus anything that was missing before using a full cromoly frame with a tapered headtube custom bolt thru dropouts pf30 bb and fenderrack mounts built up with a pair full carbon forks to allow a little more comfort at the front end and flared bars for added control although supplied with 700c wheels the substance ii has clearance for road plus wheels650b x 47c the substance ii is truely a bike that can do a