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curtis73
12-06-2006, 08:57 AM
At what weight do you guys like to go to two axles? At what point is the stability and capacity worth it compared to the added expense/maintenance?
The boat in question is a 19' I/O. The trailer it came on is not original, its just one that the dealer came up with at the last minute so I could trailer it. The frame is adequate but the axle is wimpy and the spindles have some pitting/rust. I plan on a new 4000-lb axle anyway, so should I do two axles instead? Dry weight of the boat is 2160, so with gear, a cooler full of beer, a tank of gas, and skis I'm sure it will be close to 2700. So, to be safe lets assume GTW of 3500.
The tow vehicle is a 5300-lb 73 Impala Station Wagon, so there is plenty of heft and power, but it lacks a bit of suspension stiffness, so tongue weight is a concern which is what promted me to consider two axles.

HOTPURSUIT
12-06-2006, 10:07 AM
Adding a second axle does not change the tongue weight. Your tongue weight should be 7-10% of the entire load. If you have a single axle trailer now, you can plan on spending 1500-2000 to add a second axle. (new tires and wheels, new axle, new springs and hardware, new fender, new step plates, possible new undercarriage, brakes, etc. plus all the labor). You might be better off just buying a new trailer at that point.
So to accomodate the weight of your boat and trailer, you will need to either goto a tandem axle setup with 2-3500# axles or step up to a single 5200# axle. But to answer your question tandem axle trailers are nice and they definitely tow better.

dumbandyoung
12-06-2006, 11:11 AM
i have a tandem
my next boat will be tripple axle.
they tow straighter.
more tires is also nice if you get a flat.
i got one with a single axle on the way to the river @ 11pm
and had no spare..OPPS!
.. i had to sit on the 40 for 5 hours til a tow truck came to mount a new one on my rim.
i learned a lesson .. a $400 and 5hour lesson. ha

curtis73
12-06-2006, 10:45 PM
Adding a second axle does not change the tongue weight. Your tongue weight should be 7-10% of the entire load. If you have a single axle trailer now, you can plan on spending 1500-2000 to add a second axle. (new tires and wheels, new axle, new springs and hardware, new fender, new step plates, possible new undercarriage, brakes, etc. plus all the labor). You might be better off just buying a new trailer at that point.
So to accomodate the weight of your boat and trailer, you will need to either goto a tandem axle setup with 2-3500# axles or step up to a single 5200# axle. But to answer your question tandem axle trailers are nice and they definitely tow better.
I'd be doing all the labor, and parts seem to price out at about $500 including brakes. In fact on Ebay right now there is a guy offering a complete disc brake retrofit kit for $349. Add $160 for two torsion axles and I'm in business.
Couldn't I go with two 2000-lb axles?
I have a question about the tongue weight, though... The total weight of the trailer right now is placed on three points: the two tires and the hitch. So, of the 4000 lbs, 400 is on the tongue and 3600 is shared between the tires. If I do twin axles centered under the same spot on the trailer, now the load will be carried in part by an axle that is further forward than the original. Theoretically it should reduce the tongue load by about (quick number crunching) 100 lbs, assuming a 24" axle centerline. Unless you're suggesting simply adding an axle behind the existing axle which wouldn't carry equal weight. Confused....

dumbandyoung
12-06-2006, 10:51 PM
id say by a new one and sell your old one.. shadow trailers in cypress ca would build you a nice trailer for around 4000. with led lights crome fenders and all the extras ..shadowtrailers.com
or you can pick a clean used one for about 1500

HOTPURSUIT
12-07-2006, 10:08 AM
You can do 2-2000# axles. Typically for tandem axles, manufacturers are using 2-3500# axles. You might be right there with capacity if you use 2000# axles.(so be careful)....You have the right idea about adding a second axle properly, but I bet you will find out that if done that way, your tongue weight will remain the same.(which is good if the tongue weight is correct now).... So the center of your axle spindle now on your single axle trailer, is where the new spring equalizer needs to be centered, or if using torision's then that needs to be the center point between the two spindles on the new torision axles.... (hope that makes sense).
Again, dont forget you will still need 2 additional tires and wheels, 2 new fenders, brake lines, a brake actuator if you didnt already have brakes and misc. nuts and bolts.. I bet it will end up costing you well over a 1000 when said and done, even if you do the work. Let me know how it goes..
I'd be doing all the labor, and parts seem to price out at about $500 including brakes. In fact on Ebay right now there is a guy offering a complete disc brake retrofit kit for $349. Add $160 for two torsion axles and I'm in business.
Couldn't I go with two 2000-lb axles?
I have a question about the tongue weight, though... The total weight of the trailer right now is placed on three points: the two tires and the hitch. So, of the 4000 lbs, 400 is on the tongue and 3600 is shared between the tires. If I do twin axles centered under the same spot on the trailer, now the load will be carried in part by an axle that is further forward than the original. Theoretically it should reduce the tongue load by about (quick number crunching) 100 lbs, assuming a 24" axle centerline. Unless you're suggesting simply adding an axle behind the existing axle which wouldn't carry equal weight. Confused....

curtis73
12-07-2006, 10:20 AM
Ok, thanks for all the tips. Fortunately I already have the brake controller on my car. I tow a lot :)

dumbandyoung
12-07-2006, 01:59 PM
Ok, thanks for all the tips. Fortunately I already have the brake controller on my car. I tow a lot :)
ford installs them stock.. what a great idea.!

craiginlaverne
12-16-2006, 05:06 PM
Pacific Boat Trailers can hook you up with what ever you want. Call them at 909 902 0094. They are in Chino, Ca. They can probably beat showdows price any day of the week. Shadow does build nice stuff, but so does Pacific. Its worth the time to compare. Good luck...

Sleek-Jet
12-27-2006, 08:17 AM
ford installs them stock.. what a great idea.!
Ford didn't in 1973...
With that size of boat, the number of axles has nothing to do with how it pulls, how the trailer is balanced does.
I had a double axle trailer under a 18' V-drive I owned for a while, it had so little tounge weight that it sashayed down the road like a druken prostitute... I did not like pulling it.
I also pulled around an 18' O/B that had a single axle trailer... pulls like a dream, tucks in behind the truck and away you go. The trailer is well balanced and has enough toungue wieght to make the it track well behind the truck.
Personally, anything under 19' I would have single axle trailer. They are easier to manuever and it's one less set of trailer tires I have to buy, on less set of bearing I have to maintain.