Nacra 5.5 on a four yr old galvanized trailer, all in good shape. arround 10 to 15 mph the whole trailer seems to hop or bounce. Slower speeds or faster speeds no problem, only issue is at 10 to 15? Any ideas why?
The trailer does have a bit of a long tong(if that is what you call it). Dealer suggested I cut it down if I want but I have not scene a need to shorten it.

My guess is check your tires. Might have one out of round. Check for flat spots in the treads that would be an indication.

Clayton

Turn down the Too Short

Does it happen all the time, or just a new thing? Has the trailer been put up for the winter and it happened on the first trip out? My first guess is that you have bias-ply tires and they have been sitting for a while and have flattened one side, (but not the same connotation as flat spotting). If this is the case they should return to round when they are put into normal seasonal use. Might want to check air pressures too.

Rich

Try and change the tire pressure and see if the problem changes or goes away. Chances are it is just bad tires. My trailer is very long (about 26-28' so I can fit the mast behind the RV - I have no problems at all - a longer trailer should tow better.

Did it step in Red Ants?

Could be springs are too stiff for the weight of the load. At specific speeds, you would get a harmonic effect leading to the bounce. At higher/lower speeds, the problem would disappear.

I have seen this at 45-50 mph when my trailer had 2000lbs torflex axle with an 800 weight...going above or below by 5 mph stopped the bounce. Swapping the axle for a 1000lbs unit completely cured it.

Mike.

LOL. What a picture that comment put in my head!

Thanks for the chuckle.

NEVER turn down Short Dog

Make sure the trailer was not made by an Eastern company, they tend to be very hoppy in late April. Also if you know any Free Radicals, sometime the Resonance Frequency is consistent with the Pacific Decadal Oscillations.
Otherwise make sure there is no water in your tire.

Are you serious? If so, I have never heard of that. How would water get in there? And how would you get it out? Or am I asking dumb blonde questions?

having worked in the automotive maintenance industry for a period in my past, it does happen. It usually happens when the tire sits flat for a long time and the bead comes off the rim allowing rain water to accumulate. A careless owner may try to just pump the tire up (it will take some effort to get it reseated). It will be very difficult to remove the water while the tire is still on the rim. The water in the tire will make it impossible to balance...

Also note that most of that "fix a flat" goo that you squirt into your tires will also have the same effect. It makes the tire practically impossible to balance because it stays gooey and will slowly move around the tire...especially when it sits for a period. You may have some of that goo in the tire too. I think the newer stuff is better about this though.

Goodyear once made a tire that had a layer of goey tar like substance on the inside of it and they heralded it as the no-flat tire. While it proved to be very resitant to puncture, it proved equally resistant to balancing and was quickly removed from the market.

sort of like those spinner hubs?

As long as you're not abusing the "frog"...

Water often gets in tires by being part of the compressed air that we all pump into them, unless the compressor has a water seperator. The more humidity, the more water.

This definitly happens in more humid climates. When I was in the bicycle industry and ran a shop in the Wash. D.C. area we would regularly drain condensatoin from the compressor's tank, though it would take a lot of refills before a trailer tire had water from a compressor. More likely it's a flat spot from sitting all winter.

However, if someone wanted to play a nasty trick, they could pump water into the tires. We would sometimes use a hand pump to fill some unsuspecting employee's bike tire's with water. We had a guy commute to work at the shop for a week before he realized what was going on.

I was being a smart A$$, however you can get a significant amount of water in a tire, I have seen as much as a cup in one, no idea if this would cause the tire to hop or not. but I can imagine that at certain speeds the water might go around with the tire instead of just sliding on the bottom.

In my experience it's most often tyre pressure being too high. These boats weigh very little and the tyre pressures we are used to are generally what's needed to carry much heavier loads which leads us to over-inflate the tyres on our cat trailer tyres.

Try reducing the pressure to the lowest safe alternative, sometimes noted on the tyre itself.

If the trailer has 'leaf' springs, you could try lubricating those as well.