Tongue Weight War-Gaming

[silverloaf]

I did a preliminary tongue weight check of our 88 30P using a Shurline scale. The weight measured 420 lbs at the coupler. The factory weight of the trailer is 5940 lbs dry.

The reading was performed with empty holding tanks. While we still have stuff to re-install, most is in the rear 75% of the trailer.

Has anyone ever performed a study on how weight distribution in a trailer affects tongue weight?

[Rostam]

420# seems a bit low. Are you sure the trailer was level?

I was inspecting a 1979 30 R for purchase a few years back and measured the tongue weight using a Sherline scale and it was 700# under the jack (under the coupler it would be slightly less, maybe 650#). I weighed the tongue weight of our 26 H and it was 630#. But that was before I put back the spare in the rear hatch, so I think now it should be slightly less than 600#.

Towing literature says tongue weight should 10% to 15% of trailer weight for towing stability (Sherline scale website says it should 11% to 12% for travel trailers). Avions have lower tongue weight compared to Airstreams and also tow better (this shows that just having a nose heavy trailer does not provide stability and there is more to it). Airstreams have between 15% to 20% tongue weight. I've seen a 6500# 25' Airstream with 1250# of tongue weight!!! Airstreams have poor weight distribution. Avions seem more balanced.

[silverloaf]

The 1st try the trailer was low in the back. The 2nd time it was tipped a bit low in the front (like when towing). Both readings were roughly the same. When I stood on the a-frame, it jumped to 600 lbs.

Maybe I’m a bit premature of being concerned about this until I get everything back together. However, I may have to scuttle the bike rack idea on the back if I can’t get the travel-ready tongue weight to 650 lbs.

[slowmover]

Trailer needs to be dead-level. There’s no substitute. Nose-down towing IS A SCREW-UP.

Place a carpenters level across the doorsill. This is (was) the reference point for the construction of the trailer. The bubble is your friend.

A SHERLINE and a CAT Scale weigh are going to have a variance. The CAT is the more realistic. Doesn’t much matter anyway, as TW isn’t any sort of concern with these trailers.

Depending on the SHERLINE model, accuracy will be best where the TW is mid-range in the scale.

Your hitch rigging IS a concern. 95% get it wrong. A weight-distribution hitch cured the TW problem a long time ago if it is set up correctly. The tow vehicle may be down at the stern slightly once rigging is correct, but the trailer needs ALWAYS be dead-level. Braking, handling, crosswind resistance all depend on this.


I see bike racks on the trailer rear all the time. The worst thing about them is actually two-fold:

1). Blockage of tail/turn lamps. The bikes needn’t be in front of those lamps, just close.

2). Shake & vibration. Nearly universal.

Were this mine, the bikes would be covered (wrapped) in a neutral, non-reflective cover AND securely strapped against any movement at all.

The last thing your rig needs is visual confusion from the rear. Cover & ratchet-strap it against each other.

I hope it doesn’t need to be mentioned that incandescent tail/turn lamps should have dumped the week you bought the trailer. Same for clearance lamps. No one can see them any more.

3M highest quality conspicuity tape should also be in place, ESPECIALLY on the trailer rear face. Bumper, if nothing else.