I have ordered a new mountain bike and I am contemplating some accesories. I am fairly new to the game here. I read or heard somewhere that if you have a riser bar you don't need bar ends. In fact I even remember something about people pointing and laughing at people who use them with riser bars. True? Why? Also, how important is a computer? They sure seem like a good training tool. Plus it would be good incentive to know how many miles or how fast you went. Just weighing my options and hope you can set me straight. Thanks!