Hello. There are many places that sell them. You can buy them from Agco-Allis, but these are expensive! You could try Shoup as someone suggested or also maybe THE company. loewen sells them too and St.John's Michigan has them too. If you want me to give you their web addresses let me know! I would say THE Company would be the cheapest, then Shoup, then loewen, and St. Johns and then Agco. There are also many other companies out there as well, if you want to "surf" the web. Also I would suggest maybe rebuilding the ones you have. We took the old ones and removed every other rib on the bar and hard-sufaced the remaining others and it works great!!! Kuchar came up with an idea like this and sells them for the Gleaner F too. Personally I like spike cylinder for my crops, but it depends on what you grow. The other big thing is that you should make sure you take your time and balance it right! Clean up the dirt and foreign material with a wire brush before putting on the new ones. Also make sure you torque the ( [8] I believe) nuts up well, on the bars. let me know how it goes and what you decided!