Lowering a Pontoon Bunk Trailer

CarlW

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Jun 16, 2015
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I recently got a used pontoon bunk trailer that's really tall (28") and really long (35' overall)...
I have a really shallow launch area and am thinking about lowering it.
Trailer currently has 14" rims and rather tall 75-series tires that are 26" in diameter.
Trailer is tandem axle.
My question is...
Would putting wide 10" rims with 20.5/8-10 tires, E-load, (20.5" overall diameter) be advisable?
I would get 3" lower with 10" rims. Not a lot, but the fenders could come down with these and so could the bunks, giving me 4-5 inches total.
I'm curious if a long trailer is workable with this wheel setup (have yet to see a long trailer w/ 10" wheels)... wondering if things might have very little room to tilt, etc...
Anyway, I do not ever plan on taking this down the highway. I live right next to the lake and the only travel would be to a marina about 5 miles away.
Thanks in advance....
 
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fhhuber

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Secondary solution...

Tongue extension so you can push the trailer back more without putting the tow vehicle in the water.
Its a bar with a trailer tongue hitch, several feet later a ball then another 2 to 4 ft there's a "trap" for the trailer frame.
Unhook normal towing connection. connect extension to the trailer then to the tow vehicle. Generally not good for pushing a trailer backward uphill but works great backing down a ramp

Extreme version is a cable between tow vehicle and trailer...
Needs a good wheel on the trailer tongue
You back down the ramp and line up, chock the trailer. connect the cable and pull tow vehicle forward to tension the cable so you can pull chocks and then let the boat and trailer on in.
This one is how many deep keel sailboats are launched.
 

gm280

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Jun 26, 2011
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Thanks. Work is no problem. Wondering how things would maneuver.

If you are trailing this pontoon a lot, I would stick with the tire setup you presently have. You still can lower the bunks. But there is a lower limit you don't want to cross. Remember it all works great on flat level roads. It is the dips, bumps, hills and valley transitions that will cause the problems. JMHO!
 

fhhuber

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Also... if you use smaller wheels, then the back end of the boat will go down more than at the axle... and you can end up dragging over every speed bump.
 

bruceb58

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Mar 5, 2006
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If you are trailing this pontoon a lot, I would stick with the tire setup you presently have. You still can lower the bunks.
Most pontoon trailers have the bunks right on top of the fenders so if you don't lower the fenders, you can't lower the bunks.
 

CarlW

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Jun 16, 2015
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Most pontoon trailers have the bunks right on top of the fenders so if you don't lower the fenders, you can't lower the bunks.

True. I basically have two ways to lower the trailer height: smaller tires gets the axle down... which in turn lets the fenders/bunks drop.
I think I'll put the smaller tires on.
I don't have to drive far at all to the launch and it's all dirt roads that are relatively level.
Maybe I'll keep the old wheels just in case it turns bad, haha.
You gotta love experiments!
 

CarlW

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Jun 16, 2015
Messages
24
Secondary solution...

Tongue extension so you can push the trailer back more without putting the tow vehicle in the water.
Its a bar with a trailer tongue hitch, several feet later a ball then another 2 to 4 ft there's a "trap" for the trailer frame.
Unhook normal towing connection. connect extension to the trailer then to the tow vehicle. Generally not good for pushing a trailer backward uphill but works great backing down a ramp

Extreme version is a cable between tow vehicle and trailer...
Needs a good wheel on the trailer tongue
You back down the ramp and line up, chock the trailer. connect the cable and pull tow vehicle forward to tension the cable so you can pull chocks and then let the boat and trailer on in.
This one is how many deep keel sailboats are launched.

Interesting post. Thank you.
And somewhat applicable to my situation.
 

CarlW

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Joined
Jun 16, 2015
Messages
24
Wow, that extension is l o n g
in that "win" video! A neat rig... it's got me thinking...
 
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MH Hawker

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Jul 13, 2011
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5,516
and you may be able to put the axle on top of the springs to get a few more inches lower
 

CarlW

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Jun 16, 2015
Messages
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Something I didn't consider... the brake drums on my trailer are too big to fit a 10" wheel. Glad I measured. The back plate is 11" in diameter. Not sure if a 12" wheel would even fit.
Looks like I'm kinda stuck with the existing setup ... probably have to go the extension route to find deep water.
And looks like the springs are already under the axle. Thanks for the suggestion.
 

H20Rat

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Mar 8, 2009
Messages
5,199
How about option C, find a new trailer? Scissor trailers work well for short distances. You really don't want to do highway towing with them unless you need to, but they can't be beat for bad loading/unloading. (you can drop and pick the pontoon off dry land, can't get better than that!)
 

CarlW

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Jun 16, 2015
Messages
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Yeah, probably would've done that but my boat's a tri-toon now. I put a third pontoon under it this year (homemade from 18" diameter sch 20 sewer pipe). I need and want a bunk trailer, and the custom configuration of the center log means the latest tri-toon scissors lifts probably aren't an option either ... not to mention the price of one of those things...
 
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CarlW

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Jun 16, 2015
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I'll keep the tall trailer I have. It's a good one. I'll just have to travel to a deeper launch area, I guess.
 

Silvertip

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Sep 22, 2003
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Load range E 10 inch tires are not cheap either. If the ramp you use is not very steep, you may be able to use an extendable tongue (with a dolly wheel if necessary).
 

CarlW

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Jun 16, 2015
Messages
24
Load range E 10 inch tires are not cheap either. If the ramp you use is not very steep, you may be able to use an extendable tongue (with a dolly wheel if necessary).

True, and I would need 4 of them. On amazon/ebay for about $130/pair, wheels and all. My boat is a 24' tri-toon and heavy. The trailer is old and rugged, welded steel 25' bunks and 35' overall, so I'd want the extra rugged tires if I put 10" on it..
Part of the reason for getting the trailer was the extra length. It's kinda like an extension in itself.
But I'm afraid it's too damn tall...haven't used it yet.
My ramp is 100 yards away from home, but SHALLOW, esp. this year. It's all dirt and not steep.
I am still toying with the small tires, but would have to remove the surge brakes.
I don't really need the brakes as I'm not going to trailer this this often. Probably never on the highway. I live on the lake.
A question:
The rear plates on the surge brakes are 11" in diameter...does this nix the 10" wheel option or can I change these plates?
Is removing the surge brakes difficult?
 
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