Originally Posted by
Redbullet
I'm afraid I didn't really understand the core message of this movie. With rim brakes at fast speed, on flat, descent, dry or light wet (which I avoid as much as I can), I always have to be careful not to squeeze front brake too much because if I block the front wheel, I crash immediately. I also move my but back after the saddle, to allow me a stronger brake without blocking the front wheel. I never felt a limitation in braking force with rim brakes; on the contrary (as I said), I must be careful not to brake so hard until I stop the front wheel.
This is not to say that disk brakes ale lower: I have to pay them the same attention not to squeeze so much that the front wheel stops, because I crash.
I think that the real advantage of the disk brakes can be seen in conditions which are so bad that the rim is flooded in water and mod, in such a way that the rim brake pads critically lose friction - so, poor braking power. In such conditions, disks would not be flooded in water and mud, so they would perform better.
But I can't see such conditions in the movie. What prevents him to squeeze the lever stronger and have a stronger brake - either on rim brakes or disks?
Would you have understood it better if rim brakes had been equal or better than discs in the tests he did? I thought the summary was pretty clear.
I think you are probably over-estimating the power of rim brakes when stopping from 60 kph. The initial bite at that speed is nowhere near enough to lock the front wheel. Disc brakes generate more power initially and that’s probably where most of the advantage comes from in the emergency braking tests.
With dynamic forward weight transfer under braking it is the rear wheel that is far more likely to lock up under heavy braking.