I have noticed that the downshift on the RH Ultegra STI is getting progressively worse, especially onto the smaller sprockets. Bike has done about 2600 km plus some trainer time. I have replaced all the cables and housings but it feels as though the shifter itself is the problem, almost as though the return spring on the black lever has gone completely soft. I do all my own service etc so this really irrititates me. Anybody out there experienced this problem? Thanks. NickD