Wow, this is a great thread. Lots of good discussion.
I learned to ride in the dirt, in fact my first 5 years of riding were all dirt since I was too young to drive. The rear brake is indispensable on a dirt bike, just like a street bike, IMO.
One thing I'd like to point out that's been hinted at here - if you close the throttle to reduce speed after entering a corner, you are braking with the rear wheel. Only difference is you're using the engine as a braking force instead of the rear brake itself. This is somewhat more true on the track, where corner entry RPM is generally higher, hence more engine braking force is available. So, on the street, when we are usually using a higher gear and lower corner entry rpm, a little bit of brake can be useful, as described:
I do blow corner entry speeds. When I do, I brake. I brake because I'm "guessing" I'm not going to be able to successfully get through this corner at this speed, or that if I do I will have used up all my margin for this event of the corner, and there darned well could be other things in this unknown Street corner that likely would not be there on some corner of a well known race track.
Amen, bro - well said.
I am a volunteer corner worker, have been for many years now. The track is a controlled environment, with a trained crew out there to ensure the track is clean and in good condition, and an ambulance and medical professionals at the ready. Crashing is a well planned event. That's one major difference with the street - it could literally take 15-30 minutes -or more- for help to arrive. The street demands that a greater margin of safety be applied for this and many other reasons.
Having said all this, I also do the vast majority of my braking with the front - but I use the rear brake sometimes just for practice, so I have a feel for how it works. You never can tell.....
