Kayak trailer owners

Finding that my Light Utility trailer modification has a problem I can't quite solve.  Bounce!  My Tartar trailer is rated for 1750 pound load max.  The Gross trailer weight with the Hobie Outback and modifications is only 520 pounds or so.  So I am under weight of at least 1200 pounds.  I have reduced the tire pressure to 42psi.  I have just added two 80 pound bags of concrete over the axles.  Today's road trip did not seem to be an improvement.  So, those who do have a similar trailer could you tell me what you do to limit the bounce?  I have concluded that I need to replace the leaf springs with a much lower load weight.  Will this work?

Thanks for any opinions.

Im no expert of anything unless bs'in counts, but I'd say you have WAAAAAY to heavy of a spring for your load if your getting bounc, also check load placement with tow-ability issues you want some extra weight over the tongue, but I believe lack of weight might be your issue. Also bad roads in Oregon seem to cause trailer bounce no matter the load. 

Have a 4X8 Harbor Freight rated about 1100.  Have 1/2 inch marine plywood on it.  I put 2X4s in the rail mounts, drilled a hole and put a pipe to hold the Thule saddles.  My trident 13 MIGHT hit around 80 pounds. Sometimes my wifes 40 lb sit in.  13 inch tires at rated air pressure.  Have about 40-50 lbs of tongue weight.  No bouncing at all.  and costs me about 2-3 MPG. 

I'd guess heavy springs.  If i towed my larger boat trailer empty I usually had clear lanes on each side of me. NOT fun on a grated bridge, so be careful of that.  Also, if you add weight make sure it's secure and not likely to snuggle into the car if you're in a bad accident.

Good luck.

If you dropped your tire pressure down to 42 psi, what were you running prior.  Are you running the tiny 12" pizza cutter wheels/tires?

Like Mojo suggested, load distribution can play a part in how it handles as well.  You want your tongue weight to be roughly 10% of your trailer loaded weight.

My kayak trailer/camper that I built has 3500lb rated axles, and E rated tires.  The heaviest I have ever had it loaded was 1800 lbs for a two week desert trip.  Lots of water, oil, tools and spare parts. Drug it over 300 milesbof washboard.

Usually it is closer to 1100 -1200lbs when I'm just hitting the coast for a few days of kayak fishing, packed for 2-3 guys.

It does tow extremely smooth behind all my trucks and friends trucks without bounce, shy of going over speed bumps.

Seeing that you are in Tiggerd, you could always tow it with your normal gear loaded out my way and I can see what your working with and maybe give you a few ideas to try.

Thanks for the input!  I have been looking at leaf spring replacements and found a set that would lower the max capacity down to 1250 pounds.  That would be a 500 pound reduction.  Not sure this is a solution, but it seems logical.

The tire pressure reduction from 65 psi to 42 psi was a suggestion from one of my friends at Warn.  He actually suggested that I run the tires at 30 psi because to the extremely light load.

I am going to retest my tongue weight.  With the added cement, the location over the axle may not be good.  Prior to adding the concrete bags, the tongue weight was around 65 pounds for the 520 pound trailer.  A bit more than the 10% recommended.  Still had bounce.  And I agree Mojo JoJo, our roads are part of the problem.  On the freeways everything is fine.  Its local roads where the bounce issue is most prevalent.

Insayn, let me try the tongue weight and cement bag location first.  If these do not help, I will certainly take you up on your offer.  Thanks!

Are you running biased tires or belted radials?

Can you post up a picture of your trailer? 

I would like to see what your tires are and if they are overkill for the trailer.

Is this a commercially built trailer, or a shade tree mechanic built unit? 

Are you running biased tires or belted radials?

5.3-12 Six ply rated Tire

Can you post up a picture of your trailer? 

I would like to see what your tires are and if they are overkill for the trailer.

Is this a commercially built trailer, or a shade tree mechanic built unit?

The trailer is a Tarter light utility trailer.  http://tarterusa.com/tarter-products/5-x-8-wood-floor-trailer-with-gate-ramp/  I have removed the tail gate which weighed 70 pounds.

I tested the tongue weight.  By moving the kayak about 6 inches closer to the tongue, I increased the tongue weight to 72 pounds which is a little over the 10% recommendation.

30 psi would soften the tire bounce a little but with light loads on our roads some bounce is unavoidable.

Most likely spring rate.  It's discussed lots of times on https://tventuring.com/trailerforum/

Different trailers, but the same issue.

KBStudio, ditch that trailer and put the Outback on the roof of your vehicle.  Problem solved!

Are you running biased tires or belted radials?

5.3-12 Six ply rated Tire

Alrighty. 

Those tires are definitely part of the problem.  They lack air space between the rim and the ground like a full sized tire provides.
They are closer to having the bump absorption of a rock.  A taller and wider tire will help "bigly" here.

If you truly want to smooth out the ride of your trailer, and even up the load capacity a bit a couple of things need to happen. 
Moving up to a 15" wheel will allow you to run much smoother rolling tires.
To run a bigger wheel/tire combo, you will also need to change your springs with a bit more lift.

Depending on your current hub bolt pattern, your new 15" wheels may not fit and will require a different hub. 
This is easily remedied with a different axle/spring configuration.

It all depends on what you want to spend to smooth out the ride. 
Your trailer has A LOT of potential. 

KBStudio, ditch that trailer and put the Outback on the roof of your vehicle.  Problem solved!

Actually the trailer is the my progression from the roof and a Hullavator.  I am no longer able to lift the Outback high enough to set it in the Hullavator rack.  So I modified this trailer to allow me to slide it on and off with the minimal of effort.  So, no solution there.