CanBike Instructors Workshop offered by the city of St. John's. The city now has several people who are nationally certified CanBike instructors, and the intention is to offer these courses to the public - another step forward for cycling here on the Avalon, but in this post I want to talk specifically about how the courses address emergency braking.
The CanBike emergency braking technique has the rider brake hard while shifting body weight toward the rear wheel and keeping the cranks horizontal. No minimum speed is specified for performing the test. In both my CanBike courses (I completed CanBike II as well) the instructors pointed out that the front brake does 75 % or more of the work.
After performing the CanBike exercise numerous times I happened upon a report titled "Testing Brakes" by Jan Heine, with Hahn Rossman and Mark Vande Kamp, in Bicycling Quarterly, Vol. 10, No. 1, Autumn 2011. These riders experimented with various equipment on a paved 12 % descent, braking hard after attaining 50 kmh. Their technique is pretty much the same as the CanBike manuals; note in the photo above (from the BQ report) how the rider's weight is way back behind the seat, and that the cranks are just about horizontal. Heine et al found that "the rear brake is useless during emergency stops". Should the CanBike emergency braking technique be taught then using the front brake only?
This might not be the obvious conclusion because these writers also cede that "The rear brake is useful when it is so slippery that hard braking on either wheel will cause a skid". Something else that would need to be established is whether the rear brake contributes more at lower speed. I doubt that my classmates and I in the Canbike course attained anything like 50 kmh when we performed the road test. One thing that CanBike could implement, and should I think, is a minimum speed for performing the braking test: 50 kmh may be fast for people just learning the technique but surely an emergency stop from 30 kmh is something that should be in every bicyclist's arsenal.
The Bicycle Quarterly report found a wide discrepancy in performance with different brake pads; CanBike instructors would certainly do well to keep this in mind when evaluating students.
By the way, BQ tested with the front brake controlled by the right hand brake lever; for most people this would be the stronger hand but it's also the case that bicycles in North America are normally set up opposite to this! The BQ report doesn't go into it but I concluded that this is one aspect of bicycle set-up that should have no default - the stronger hand should control the front brake!