Welcome to the new and improved Proflex / K2 Tech Forum!
sorry to be a bit kate in the conversation - but the Ti springs have such a high rating because they are very short and don't compress much. You will only get an inch of travel out of them. When K2 was still a bike company, their pro XC riders used the Ti springs. I was riding with Nora Roesche (XC womens Worlds 1998ish) and held her 957/K2 5000 mashup bike for a bit and it must have weighed about 20 lbs. callumrds