Yep, the rear is a 71 260 and I have the preload cranked up so high its not working right. I do have a 72 91 progressive but thought the 76 would give me a better sag setting, I took this spring off my 05 250 exc. I weigh in about 205. A friend of mine does suspension for a living, he rode it for a bit and suggested the 52 springs with a 145mm oil level and 7.5 weight, its near perfect in my opinion and more than sufficient for my riding skills. I will probably not go with the remote tanks since it so good right now. This has been the most successful upgrade I have made to my 640.