I need some help with my new boat/trailer set up. For some reason, whenever I drive across a bridge my trailer starts bouncing like crazy. I have complete control of the car and boat, but it definitely isnt right. It does fine driving down the highway, which is what I dont understand. Any help would be appreciated! I noticed today that the tires were a little underinflated. Max psi is 50 and they were around 44, and I will see if that helps. I guess I need to move it forward or back, but hoping for advice before I attempt that. Here are a couple pictures, but I am not sure they are much help. If you see anything I can do to help the situation fire away! Thanks as always
I think it’s the joints in the bridges. Mine does that on all of the big bridges on 526.
I think it has something to do with your speed and the distance between joints. It gets bouncing at a frequency at certain speeds. Try slowing down or speeding up to stop the bouncing.
Hope this helps. Maybe somebody else knows more about it than me.
Semper Fi
18’ Sterling
115 Yamaha
Big Ugly Homemade Blue Push Pole
Boat trailers don’t have shock absorbers. When your car hits a bump, the springs flex with the bump and start bouncing. Your shock absorbers (or struts) are dampers that stop the bouncing. So, if your trailer is bouncing all the time, your springs are to soft. Are they old/degraded to the point that they flex more easily than they should?
If they bounce excessively in specific situations, they may be structurally fine, but, end up matching the frequency of the natural trailer bounce with the frequency of the ‘bumps’ in the road. The first bump in the road gets it bouncing. Each successive bump happens to line up with the bounce and add to it. Referred to as ‘sympathetic.’ So, you need to either change the frequency of your trailer (new springs?). Or, slow down so when you hit each successive bump in the road, it does not match up to the existing bounce in the trailer. You could speed up a little, but, I would not advise. It may get a lot worse before it gets better. (See Tacoma Narrows Galloping Gerty on youtube to see what a sympathetic vibration can do. If you notice the cable anchors on the Ravenel bridge, you’ll see shock absorbers to avoid this problem. 'Hope they work.)
I guess you could add shock absorbers. But, I think they’d last about 5 minutes after a few salt water dunkings. Never seen a boat trailer with shock absorbers.
Thanks for the info! I will try those things out next time I take out that way. I will say that I noticed a flat bed bouncing around on the same spots along the bridge. I have never had dual axels or torsion bars so I was just wondering if that was normal. I am also going to play around with the tongue weight. Does bouncing occur more with a heavy tongue weight or if it is too light? Thanks!
Do see the one issue that would help a little is your ratchet crank is sitting to low on front of boat . Won’t help the bouncing that much but puts your center of gravity in a little better shape.
Wicked fishing
175 CC Pioneer Bay sport
90 Yamaha 4 stroke
I will try to find a scale…any recommendations? If I move the ratchet thing up, won’t that increase the tongue weight. It would also cause the bunks to stick out further. Any problem with that? Thaanks
