Originally Posted by Oranoco

I think where Tony is going is that because teh front is braking hard the weight transfers to the front thus making the rear of the car light and as a result more likely to lock up. By increasing the effort the car will brake more level and thus stop quite such an excessive transfer of weight away from the back of the car

Originally Posted by NUTS RuS

you must have read my PM I sent to Karlos this morning

If it locks up under braking it could actually need more on the back to stop it, depending on what its doing.