Lower Gear or Brakes? (On a Downhill or Turns)
By: James R. Davis An interesting everyday kind of question was asked recently: quote: If you have a long, descending, curving highway merge ramp, do you use a lower gear to provide some engine braking if you have to let off the throttle, or do you use a higher gear and use your brakes in the curve if you encounter slower traffic, trucks, etc.?
Most experienced riders will virtually always opt to use a lower gear whenever they are about to enter an off ramp or when dealing with a meaningfully sharp turn. This affords then the best responsiveness (acceleration as well as engine braking) potential possible to deal with the unexpected.
But the question was really more about brakes than about gearing.
On a long downhill you want to use engine braking whenever possible for two reasons: - To prevent premature brake wear
- To prevent temporary overheating of those brakes
If you do mostly touring (long distance, and therefor high-speed highway riding), you should have little concern about premature brake wear as you use your brakes infrequently compared to miles travelled.
On the other hand, temporary overheating is a major concern from a safety point of view.
Your brakes work by converting kinetic energy (movement) to heat. In the process the brakes can get VERY HOT as they can only dissipate that heat at a modest rate. When brakes overheat they lose efficiency. In other words, it takes more braking effort for hot brakes to scrub a given amount of speed than it does for cooler brakes.
Further, if that overheating gets severe enough it will no longer be a temporary loss of efficiency as they can bake and glaze into surfaces that are permanently less efficient at doing their job.
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(James R. Davis is a recognized expert witness in the fields of Motorcycle Safety/Dynamics.)
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