cyccommute 

I agree with you that there are situations where it is difficult to avoid sliding the rear tire. On clear, flat, dry pavement, control of the rear tire under braking is much easier. Add in water, sand, leaves, ice, etc. and that changes the situation significantly. Braking become far less predictable. You can do everything right and still end up sliding the rear tire.

Yes, you can avoid skidding if you don’t use the rear brake [Edit: Oops. Meant rear but said front] but you are also throwing away some of your decelerating ability and, more importantly, an important indicator by doing so. When you initiate braking, while both wheels are in contact with the ground, about 20% of your deceleration comes from the rear wheel. The amount of deceleration decrease rapidly as your weight shifts forward to the point where the rear wheel lifts and the front wheel is providing all of the deceleration. While this is where you approach maximum braking, you are also depending on the front wheel to provide both braking and control. The front wheel does a great job of steering the bike but it does a lousy job on its own…because it can steer. Keeping the rear wheel on the ground and rolling will keep the bike more stable.

To keep the rear wheel on the ground, get off the front brake by releasing it momentarily. In practice, I usually release both and then get back on them. You are in a situation where you really don’t want to think about too much and releasing both brakes takes less brain power. By doing this, you are decreasing your deceleration (slightly) but it allows the center of gravity of the bike to settle back down slightly. Moving that center of gravity takes time and is a curve. By releasing the brakes, you have flatten the curve just a little but you now have a bicycle instead of a unicycle…with a pivot in the middle of it.

There’s another aspect of braking that many people don’t practice nor understand. Pushing back and dropping down moves the center of gravity. A lower center of gravity increase the amount of deceleration you can achieve before you lift the rear wheel. You don’t have move all that much…a few inches both rearward and down…just about doubles the amount of deceleration you can achieve before wheel lift.

Under braking, the bike is a lever that is trying to push you up and over the bars. By moving back and down, you’ve increased the lever length which requires more force to lift the load. The result is you can slow faster without skidding.

As to your practice tires, frankly, your tire is toast. You do have a tire to practice emergency stopping on. Mount it up and go find a parking lot. Measure out a distance (or just eyeball it) and try braking while in the “normal” seated position and while pushing back and down on the bike. Practice it a lot until it becomes second nature. You can also practice this on gravel and wet grass. If you can learn to stop on those you’ll be golden.

Alternatively, get a mountain bike and have fun riding off-road. A hour of off-road riding will teach you more about braking than years of road riding.