re "dragging brakes" in general, cycco will back me up on this one -- its just not a good idea to drag brakes, any brake, for any period of time.
Good hard application of brakes to bleed off some speed, then let off to allow heat to go down a bit, then good hard braking again, repeat -- this is the same in cars as well, to avoid overheating and fading braking systems.
Dragging rim brakes or disc systems will cause overheating and fading, I've done this in cars as well as touring in mountains with bikes with rim or disc brakes.
I've toured a lot in mountains loaded up, and while I am a light rider, not dragging brakes is key.
It's all about managing heat and keeping it at a reasonable level.
I am however very comfortable at speed and judging safe speeds for the conditions.
Just another long, disproven, urban myth from decades gone by.
In fact, pumping your brakes (repeatedly applying and releasing them) is generally less effective and potentially more dangerous for managing heat than proper technique.
The physics of braking is essentially the conversion of
kinetic energy (motion) into
thermal energy (heat) through friction. To slow a vehicle by a certain amount, a specific amount of heat must be generated. Pumping the brakes doesn't change the amount of heat required; it just changes the timing of when that heat is generated.
Why Pumping Isn't Better for Temperature
- Reduced Cooling Time: While it seems like the "off" phase of pumping allows the brakes to cool, the intervals are usually too short for significant heat dissipation. High-performance braking systems require consistent airflow over time to shed degrees.
- Peak Heat Spikes: Pumping often leads to more aggressive stabs at the pedal to maintain control, creating "flash" temperatures that are higher than the steady heat generated by constant, light pressure.