"Short Wave Sportfishing" wrote in message
...

On Sun, 12 Nov 2006 13:02:36 GMT, Gene Kearns
wrote:

Weightwise it will handle it, but when you hit the brakes, good things
don't tend to happen in quantity. My trailer started life with brakes
on one axle and I added the other axle's brakes after a few years.
Stopping potential was immensely better.

That's a logical assumption - adding hardware always increases
potential.

However, in the case of a trailer, stopping potential isn't really
what trailer brakes are designed for. The stopping power is with the
tow vehicle, the trailer braking systems, as I understand it, are only
for controlling the trailer and do little to stop the tow vehicle.
It's not like a tractor trailer combination.

Later, I found justification for this in the following quote:

"A rule of thumb for brake system capacity is to rate the brake system
stopping capacity at the same value as the axle capacities.
For example: If you have a tandem axle trailer with two 3500# axles,
but only one of them has brakes, then you would be advised to
calculate your best stopping capacity at 3500#. "

borrowed from this article:

http://www.championtrailers.com/Drum...BrakeArtcl.htm

Interesting, but I have a couple of questions concerning their
assumptions.

First of all, the article assumes level roads, level loads and in the
real world, in particular with tandem axles, that ain't necessarily
so. Loads can be uneven, front to back and side to side which places
different loads on all four tires. Uneven surfaces, such as a high
crown in the road, place different stresses by shifting loads
side-to-side. Corner braking - the list is endless.

Additionally, you a dealing with hydrostatic, unboosted pressures on
the individual units (in their scenario of four discs) which, to me at
least, will introduce some instability in the pressures applied by one
single actuation cylinder. Given a potential combination of uneven
load, uneven surfaces and uneven brake pressure, I can't see where
their assumptions, which are interesting, are accurate.


I understand differently. Example:

My truck has a GVW of 8,400 lbs. To meet federal stopping distance
requirements, the brakes must be capable of stopping that weight in a
certain distance from a certain speed. It does not include added weight of
a trailer.

Adding a trailer requires the trailer brakes to be capable of stopping the
*trailer* GVW within the required distance.

Most trailers with electric brakes can be *locked* if the gain for the
controller is set too high.
The fifth wheel I had was a triple axle and it had brakes on all 6 wheels.

Eisboch