I have heard that ti bikes are not as stiff as what I am currently riding which is aluminum. I would like my next bike to be one that will last a long time but which is also fast and fun to ride. Question: Are there ti bikes out there that are known to be stiffer than others? Are there major brands that are known to be flexy is the bottom brackett area that I should stay away from. Recommendations for a good stiff bike of ti would be greatly appreciated.