Fifth Wheel Hitch Decision

jshupe wrote:

SoCalDesertRider wrote:

jshupe wrote:
Their truck has a GCVWR of 31100#. They will be under that limit, which is the one to look at when it comes to safe braking. Trailer brakes fail, and I'm pulling these speculative stats out of thin air, but the rate of occurrence is probably far less than a tire blowing out, and no more often than a leaf breaking or suspension bolt shearing. Not something to be overly concerned with as long as you are under GCVWR, inspect your trailer regularly, and take care of your rig.

The truck's brakes are NOT designed to stop it's GCWR weight. They are designed to stop it's GVWR weight. Big difference.

They're not designed to, but unbraked trailer braking is part of the equation for determining GCWR. From section 4.5 of J2807:

Performance Requirements for Determining Tow-Vehicle
Gross Combination Weight Rating and Trailer Weight Rating wrote:

4.5 Combination Braking
This section defines combination braking performance requirements at GCWR. This section should be used to determine any or all of the following TWR/GCWR limits: maximum unbraked trailer limit, conventional braked trailer limit and fifth wheel/gooseneck braked trailer limit.

4.5.1 Combination Braking Performance Requirement Summary
The tow-vehicle brake system, in conjunction with appropriate test trailer(s) per 4.1, shall be capable of meeting certain braking requirements for the specified GCWR. The following table summarizes metrics, requirements and test methods for specific performance attributes. The purpose of 4.5 is to determine the suitability of the tow-vehicle brake system in conjunction with a trailer. Tests are to be run without the use of trailer brakes.

...

I would have to see the chart and other information to make any conclusions.

The wording you posted talked about tow vehicle braking performance with an unbraked trailer, and talked about tow vehicle and trailer combination braking performance with a braked tag trailer, as well as with a braked gooseneck/fifth wheel trailer.

FMVSS tests and certifies the braking performance of all motor vehicles, at their GVWR weight, not at a GCWR weight, and not at the sum of the front and rear axle weight ratings weight (except for commercial vehicles who's GVWR equals the sum of their axle weight ratings).