Originally Posted by
metro2005
In an emergency stop you weight shifts forward and therefore lifting weight of your back wheel. When you brake with your rear brakes you only get a skidding back wheel and no stopping power. On a shortwheel based recumbent bike its even worse with all the weight on the front wheel you have almost no stopping power at the back wheel at all.
That your weight shifts forward is certainly true...
under all conditions. Even if the bike has only a coaster brake on the rear wheel, the weight shifts forward. Ask any 10 year old about skidding the rear tire with a coaster brake equipped bike. That's not the point of this thread. No one that I've seen post here is say to use only the rear brake. They are talking about using both brakes vs the idea that you should (almost) never use the back brake.
Your recumbent example is a special case, however. For regular bikes and longer wheelbase recumbents, the rear brake's contributions aren't zero until the rear wheel lifts off the ground. Even in your short wheelbase example, the contribution from the rear brake isn't zero. The time between going from contributing some deceleration to contributing zero may be shorter but that's a function of the bike geometry.
Originally Posted by
metro2005
When in slippery conditions the rear brake can be usefull as well as when going downhill. You can then use the front and rear brake at the some time or switch between them to let them cool down.
You can also use the rearbrake to slowdown a little bit but not for coming to a complete stop.
The rear brake is useful in almost all situations until you lift the rear wheel off the ground. At that point it doesn't matter.
On downhills...high speed downhills with a 50 lb touring load in mountainous terrain...I've never experienced wheel overheating because I don't drag my brakes. You will get far less wheel heating if you use
both brakes to check your speed momentarily, then get off the brakes entirely. Simply sitting up can have a dramatic effect on speed too.
Originally Posted by
metro2005
In all other conditions: the front brake is the best option, it gives you the most stopping power (about 80% of the stopping power comes from the front brakes) and the most control over your bike because when your backwheel skids you fall.
Therein lies the lack of understanding. Yes, you get most of your power from the front brake. But you should just throw away 20% of your deceleration because you are afraid of sliding the back wheel. As I said above, when the back wheel starts to slide, get off the
front brake. You may lose a small amount of deceleration but you'll gain a lot more control of the bike.
And a skidding rear wheel doesn't necessarily mean that you are going to crash. Again, ask the 10 year old.