I ran across a rough formula for pin weight on fifths

[Greywolf]

Approximately 15% to 25% of the gross trailer weight (Dry weight of trailer, plus maximum expected load, INCLUDING full tanks). I found this in a leftover installation guide for a Cequent fifth wheel mounting set of instructions. To be on the safe side - figure 25% of total tow (GVW) The trailer and it's contents together MUST NOT EXCEED truck or hitch tow ratings. The pin weight is another story and is a seperate computation. This may not be applicable to travel trailers, utility trailers, or especially car haulers. Cars are usually heavier at one end or the other, depending on engine and tranny weight. Utilities are usually loaded "TONGUE HEAVY" to help prevent sway, but if all of the load is forward - LOOK OUT! I haven't seen a busted hitch head yet, but I haven't seen it all yet either... I'm sure someone broke one. This is intended as a guide, not the final authority on it. If in doubt - use a bigger truck and a beefier hitch.

[acheda]

I would think that 15% would be suitable for a single rear wheel setup and 25% for a DRW. One more reason for a true fifth wheel instead of a ball & socket.

[95van]

Not saying your formula is wrong, but just wanted to add that fifth wheel trailers are very forgiving compared to tag alongs. I welded a reciever to the back of my fifth wheel camper so I could haul one of those platforms to hold a 150 quart cooler when camping at the races. When I took it for a test run full of ice, food and beverages, I found there was so little pin weight that the pin was pulling up on the hitch once in a while on a bump. Needless to say, I gave up on that idea, and only use the platform for a messy but light campfire ring now - but the trailer still handled fine, where as a tag along would have had the tail trying to wag the dog badly. Fifth wheels tow sweet !

[Greywolf]

Good point.

ROAD TRAINS need a lot of forethought before attempting them...