I never found a situation where I needed to turn off the high speed damping. It is only there to catch the bars for you. If the low speed is turned up too high, like going from a high speed rock road to low speed tight trails, I've had to turn it down. It's rideable, but you notice the extra effort to flip the bars. I've seen several of the dampers fail, leak, develop catches, break. Not the Scotts or the Fastway. I've only seen a very old Scotts get weak, may be from old fluid.