I plan to take my 21SC places (mostly bigger WA lakes) this coming season. That means some road time.
Boat and trailer are roughly 1000lbs.
So far I have trailered it on one longer and two short trips.
Trailer has leaf spring suspension and I am not overly happy with the bouncyness. Trailer tracks great but the boat could do with less impact energy and vibration.
What are the opinions and solutions here on torsion vs leaf spring when it comes to ride quality for the boat?
I am not interested in tire wear, or how the trailer tracks for this argument here.
Comments on axle-less solutions?
Are you using anything else to add dampening, reduce vibration for the boat / the load?
(Foam, or similar in cradles, mounts, etc. ?)
(Cat) trailer suspension and dampening
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Posted: Feb 03, 2020 - 05:57 PM
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Posted: Feb 03, 2020 - 08:08 PM
I've added shocks to a trailer and it was way easier than I thought. Still bounces a little, but only once. I intended to put airbags on that I have but there wasn't enough room. This on a 5x10 utility trailer. On my boat trailer, when I replaced the springs I went with 1500 pound springs, which is as light as I'd go and probably too light. Got the shock kit from maybe etrailer? The other consensus is to run larger tires at a slightly lower pressure.
If moneys not a problem, there are some fantastic trailing link torsion suspensions that would be the bomb, but I just remember they were pretty high dollar. Think the shock kit was less than $100. Cheap and took about 3 hours including touch up paint. Worth a shot. I need to do the same for my new trailer.
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Chuck C
NACRA 500 Mk2
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Posted: Feb 04, 2020 - 07:14 AM
First thing I would look at would be the leaf springs themselves - are they sized properly for the load you’re carrying? I’ve never seen shocks on a Hobie trailer, but getting the right springs sized for your load should help. Just make sure you take accurate length and width measurements and swapping them out should be pretty straight forward.
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Posted: Feb 04, 2020 - 10:15 PM
nope, you dont see shocks on trailers much at all. Don't know why exactly. Maybe too complicated for a cheap, light trailer, perhaps or maybe theres not enough weight to cycle the shocks and get use out of them. But, new springs are very easy and cheap.
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Chuck C
NACRA 500 Mk2
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Posted: Feb 05, 2020 - 11:06 AM
Thanks for the input.
I'll have to check on the tire upgrade! They are due anyway - old and fairly hard.
I did look at shocks at first but did not follow it up with more research as it seems to involve more fabrication - maybe not so much afterall?!
Yes, I made this post about ride quality but how would this hold up to saltwater? I was talking lakes but I'm just three miles from saltwater, so that will happen as well.
Checking the leaf pack is an option for sure. Instead of using shocks, are those addon rubber dampeners any good? I do recall very little suspension action from the trailer when moving around on the boat - and I'm 200lbs.
In my head, torsion bar is still a thing but I have no personal experience with them!
What will help decide this is also me measuring the trailer width. Looks like the smallest ones are 1500lbs rated and if I need a longer axle I'm looking at 2000-2500lbs rated ones.
The torsion stubs / axle less option would depend on the trailer structure - does it require a bar?!
I'll have to gather some info next time I'm with the boat & trailer. -
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Posted: Feb 05, 2020 - 02:37 PM
I've had a couple of trailers with torsion axles; in a previous life, I had a 28' gooseneck horse trailer with tandem torsion axles. It was nice relative to leaf springs b/c the trailer sat lower to the ground and if you blew a tire, the axles didn't kick up on the pivot.
My current cat trailer has a torsion axle... well, I guess it's actually two axles b/c there is one on each side. I think it rides just a hair stiff, but I think it will be better now that I've added some weight by converting it to a tilt trailer and lengthening the tongue by three feet. It is nice b/c the trailer itself sits 6-8 inches lower than it would with leaf springs.
The lower ride height is something to consider if you think about switching axles. You can look at places like etrailer.com; they have quite a few "axle-less" torsion setups, so width isn't an issue. -
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Posted: Feb 05, 2020 - 03:44 PM
When I did a lot of traveling double stacking boats, I simply went up a level on the leaf spring. Take a picture of what you have, and go to a trailer dealer. Be sure you do get something that will handle the water immersion if you ramp launch the boat. Here, we have to deal with salt water and I ramp launch my cat in come locations. It is a simple solution you can change out yourself.
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Scott
Prindle Fleet 2
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Nacra 5.0
Nacra 5.8
Tornadoes (Reg White)
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Posted: Feb 06, 2020 - 02:11 PM
On the damping subject, leaf spring design has some damping built-in. One end is fixed and the other slides as the spring flexes. The sliding causes friction which damps the motion. In my experience, this is enough. No need for the complexity, cost, and weight of the additional shocks.
Torsion design might give you just a bit less unsprung mass, but not sure the cost/complexity of the change would be worth it. Haven't studied the implementations well enough to know if there is intrinsic damping or not.
Key to me is keeping the spring-rate matched to the load. Two stiff and things will bounce all over the place. Too soft and it will be smoother but you can bottom out and risk permanent deformation of the spring (a friend ran into this issue after converting his single-stack to a double-stack with out changing the springs for the additional load)
I've pulled my cheap and simple '80's vintage "Little Dude" trailer with my F18 on it all over Michigan and down to the FL keys twice with zero issues. I did move up from 8" to 12" tires. Mostly to make life easier on the bearings. I think the larger diameter tire has less vibration since its spinning at a lower rpm.
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Jeff R
'88 H18 "Jolly Mon"
'10 C2 USA1193
NE IN / SE MI
cramsailing.com
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Posted: Feb 07, 2020 - 04:55 PM
Reading the OP again, I'd guess you might be over-sprung or under-loaded. If there is room in the trailer box, you might put all the heavy stuff in there and any remaining light stuff in the back of the car.
Using foam or good quality cradles to manage point loading is always a good idea.
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Jeff R
'88 H18 "Jolly Mon"
'10 C2 USA1193
NE IN / SE MI
cramsailing.com
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