What is the difference between having a bar with the spindle at the end versus one without? I picked up a second Husqvarna 61 last week, and the bar doesn't have the spindle at the end. My other 61, which is at least 15 years old, has the spindle on the end of the bar (as does my smaller 136). I have heard these being referred to as "hard" and "soft" bars, but haven't been able to find out the main differences or advantages of one over the other. Thanks!