We counted the sprockets on the rear hub. There are 18 and it is 3" wide. Is this a typical size for a 26" bike?
It does not feel like anything is rubber. We have already turned the bike over and adjusted the rear hub bearings. I don't think the bearing grease would be caked on because everything is new on the bike, including the bearings. My first two suspects would be the larger ballon tires or possible and incorrect rear gear (the front gear is original, the rear gear is new and came with the new wheels I purchased).