I ordered some upgrade parts for my MTB last month and I received them all but the shifters, seems that Shimano and Sram have stop the manufacturing if some 9 speed shifters and have slowed down on the rest. I was told both companies are going to 10 speed drive train systems. My question is, is 10 speed really necessary for a mountain bike. Sounds like a lot of readjusting after each ride since the shift tolerance will be so close. Just wanted to know if anyone else felt this way?