Al,
I believe that if the tongue weight is at least 10% or greater (of the trailer weight) there should be no problem. Therefore if lightly loaded, as you indicated, the trailer was likely near or under 3500 lbs. You had two bikes on a bumper hitch.
Let's try a little math exercise using assumptions.
Assume: Trailer 3500 lbs; tongue weight (w/out rack) 12% of 3500 = 420 lbs.
N.B.: I had the geometry wrong in original post. Below was amended to reflect moment arms measured from axle attachment point on the frame.
Geometry: Axle-to-rear bumper = 7'3".; Axle-to-hitch = 12'9".; bike rack arm behind bumper approx 1 ft(?).
Bikes plus rack = 2@35 lb + 10 lb = 80 lbs total. (replace with actual weights).
Moment around trailer axle = 420 lbs*12.75 ft - 80 lbs*8.25 ft = (5355 - 660)lb-ft = 4695 lb-ft. (sum of moments)
Question: What is the new tongue weight?
Answer: Tongue Wt = Sum of moments / Arm = 4695 lb-ft / 12.75 ft = 368lbs.
Result: Tongue weight dropped from 12% to 10.5%.
Reason: Long moment arm to the bike rack.
The point - small increments of weight at a long moment arm have a large effect. The geometry is such that each 10 pound increment of additional weight behind the bumper removes about 6-7 lbs pound from the hitch. If the bikes and rack weighed more than in the example, and the hypothetical tongue weight were even less than I used, the final tongue weight could be closer to 9%.
Denny_A
Quote:
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Originally Posted by ColoradoAl
-------snip---------noticable sway----snip
The trailer was lightly loaded and so was the TV since we were out for a quick three day camping trip. I'm aware that it is
recommended that the bulk of the weight should be concentrated in front of the trailer axle and that's where I stowed most of the things we carried inside the trailer. However, I had the dealer install a hitch on the rear of the trailer for my bike rack and I had two mountain bikes mounted there for this trip. I just occurred to me that that could be my problem.
As a greenhorn to the trailer world, I may have shot myself in the foot. I would appreciate any constructive advice on how to deal with this fine mess I may have gotten myself into. ----snip-----------
ColoradoAl
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