trailer brakes

[Monkey Butler]

Years ago I would have thought nothing of going without brakes but now I worry more about things like insurance, tickets and more importantly the safety of friends and family that might be in the car so I feel a lot more comfortable with my brakes.

Originally Posted by Destroyer

... put one set on the front axle.

To follow the letter of the law in many states, and I think Florida is one of them, you are required to have brakes on both axles if they are installed at all.

If you do go with a single axle install then I have to disagree with you about putting them on the front axle. While it seems like common sense that the front axle would be the best location froman engineering standpoint that is not true. The brakes will be more effective on the rear axle and here is why.

Look at the crappy drawing below and imagine the trailer is standing still with the road rushing under it and the hubs spinning in a clockwise direction. When the brakes are applied you are essentially trying to lock the hubs to the axle. The torque from the rotating wheel/hub is then transmitted to the springs. If this happens on the front axle then the forces will cause the front spring to act on the equalizer in a way that pivots it in a counterclockwise direction which will tend to unload the front axle while increasing the load on the rear axle.

If the brakes are on the rear axle then the rear spring is acting on the eqaulizer but the net result is the same except now the greater the torque the greater the dowforce on the axle with the brakes on it.

I actually witnessed a trailer with the front axle hopping under braking but at the time I didn't understand what was happening.




If you don't believe me then you can double check me here:

http://www.championtrailers.com/techsup.html

When only one brake axle is being installed on a tandem axle trailer, the brakes should be on the rear axle for maximum system performance. Rotational torque applied to axles during braking shifts the equalizer and applies more weight to rear axle. If brakes are installed on the front axle, the wheel may skid during braking. Brakes on rear axle are more effective as the equalizers shifts and the rear tires dig in to the pavement.