Originally Posted by DannoXYZ
Yeah, that will build braking forces too fast for you to adjust. I think the OP wanted a simple answer, so here it is:
F/R balance__braking-force
50/50 - initial braking, under 0.25g deceleration
60/40 - 0.4-0.6g
70/30 - 0.6-0.9g
80/20 - 0.9-1.3g
90/10 - 1.3-1.5g
100/0 - 1.5g+
Where are you getting those numbers? Forester, who I'll believe on this issue because he's an engineer, says you can do about 0.3g max using the rear brake, and about 0.6g max with the front brake before you go over the handlebars. Using either brake causes weight to shift from the rear wheel to the front; at the limit of braking all of the weight is on the front wheel and the rear wheel contributes nothing.
I normally only use the front brake. The only case where you can get more braking power using both brakes than just the front is when conditions are so slippery (or your front brake is in such bad repair) that you can't generate enough braking with the front brake to lift the rear wheel.
I'd be surprised to see any vehicle with rubber tires pulling 1.5 g.