Add another axle?-gctid369531

[Guest]

My trophy weighs about 1975# dry weight according to the website. Add to that 316# gas, 2 batteries, kicker motor, downriggers, and gear I think I am pushing 2750#s. My single axle Karavan is rated for max load of 2860, so I am pushing the trailer right to the limits with the boat. The trailer seems a little short, even with the winch post slid as far forward as it can go, the boat seems to be right on the balance point, and on rough roads it will bounce a little on the trailer. The tongue weight is acceptable and pulls fine, but the camber of the loaded axle makes the tires wear on the inside of each, making them wear out quickly. I pull the boat 100 miles one way on the average trip, but have trailered it over 500 miles each way or more on occasion.

The question on the table: Buy another axle, leaf spring set, and fenders and add another unbraked axle(labor and welding I can do easily) or replace it with a new trailer entirely?

Thanks for any experienced opinion.

[Guest]

Your axle came out of the factory with about a 3-4 deg bow up in the center, providing a camber of approx 1.5-2 deg on each wheel. This provides a level wheel at rated weight. Over time, and with age this bow tends to straighten out. It sounds like you are kind of a DIY person, I my first suggestion is to remove the axle, and take it to the trailer shop where they can put a bit more bow in it. Or, you could do it in your driveway with some bricks out at the ends, and a heavy truck, but that's not a calibrated way.

I would be more concerned about the tire quality than the axle issue or adding another axle. Get the best trailer rated tires you can, and keep them covered from sun when not in service. Your still under the max gross weight of the trailer which has a safety load factor built in.

[Guest]

That really isn't a big boat and shouldn't need tandem axles.

Most axles are rated at 3,500 pounds or 5,000 pounds.

See if there is a sticker on your trailer that says the GAWR, that is the Gross Axle Weight Rating.

More than likely it is 3,500 pounds, so it is plenty sturdy.

New axles arent that expensive if yours is sagging. You could even go with a 5,000 pound which will have bigger bearings.

Adding another axle is a little complex because you would have to move the original one forwar or backward, depending on which one you put in front.

http://www.southwestwheel.com/store/p-2303-5200-lb-standard-spring-trailer-axle.aspx

[itsabowtime2]

What type of tires are you running? If they are Bias, which are less expensive than Radial, they will wear quickly. If you really want duel axles I would sell the trailer and purchase one designed that way.

Or

How many lugs does your axle have?

Swap out the axle for a 6 lug which is usually a 5000lb rated axle.

[2850Bounty]

If you add a second axle, you'll need to move the existing axle either FWD or AFT to maintain center balance with the new double axle set up.

This may mean building an adjustable substructure for both axles to attach to.

If you do add an axle, great time to include brakes, IMO.

As for camber, you could have the existing axle camber checked and/or re-cambered by a font end alignment/frame shop.

Since you had to move the winch tower forward this much, it sounds to me like your trailer is a bit too short for the hull.

Longer tongues cause a trailer to track better, and are much easier to reverse with.

.

[yachtman]

If your boat weights 2750lbs you are already over your rated load. You have to add the weight of the trailer also. Plus if you add all the junk excuseme gear in the boat I bet it weighs more than you think.

Having said that yes it is probably your tires that are the limiting factor. You need to look at the load rating of the coupler. See what it says. If its sufficient then its most likely tires. Make sure you use "D" rated tires if you can. Your boat will tow much better if you had 2 axles but that's a bit of work. It will most likely intail more than adding another axle. You may need to move the one you have. Also the hangar set up for a double axle is not the same as a single. You may need to place new spring hangers depending on what you have and what you need.

Also you have to take in consideration the center of balance and that may require that you move the existing axle. For long life of a trailer you shouldn't exceed 80% rating of the trailer.

[boatworkfl]

I think you would be money ahead if you buy a new/used trailer and sell your old trailer.

Installing a 2 axel set up will be quite spendy.

[yachtman]

+ 1 on most of these posts. I built a 40ft trailer a couple of years back. I decided I didn't like the center of load and moved the axles (a tripple ). I was actually alot more work than I thought. I was thinking about adding a 4th axle but it would cost $1000 plus to do it. Some states require brakes on doubles. You should have brakes on both axles adding to the expense. I know how to build and rework trailers. If it were me I would buy a different trailer.

[Guest]

Your overloaded on the trailer.

As David said, you need to add the trailer weight - for that one probably 700-1000 lbs if galvanized steel.

Get a different trailer. The fact you are wearing your tires on the inside shows too much weight. Mic the spindles - I would guess they show upward bend which is overloaded.

[Guest]

The OP listed the 'max load' as 2860. I have to mildly disagree with those who think this trailer is overloaded. The 'load' is what you are allowed to carry, and does not include the dray weight of the trailer itself. This is referred to often as 'payload', or what the trailer will carry in payable weight. If we take the axle as a typical 3600Lb which is common for the C or D rated tires on 14" rims, that leaves 740Lb for the trailer weight and the balance for the payload.

It appears that Karavan doesn't sell the same exact trailer but the closest approximation is the KCB-2800-82L for a boat from 17-20'.

http://www.karavantrailers.com/spec_sheet.cfm?photo=kc_bunk%2Ejpg

This trailer weight is 709, and well under the rating for the axle and tire installed.

[Guest]

docmirror wrote:
The OP listed the 'max load' as 2860. I have to mildly disagree with those who think this trailer is overloaded. The 'load' is what you are allowed to carry, and does not include the dray weight of the trailer itself. This is referred to often as 'payload', or what the trailer will carry in payable weight. If we take the axle as a typical 3600Lb which is common for the C or D rated tires on 14" rims, that leaves 740Lb for the trailer weight and the balance for the payload.

It appears that Karavan doesn't sell the same exact trailer but the closest approximation is the KCB-2800-82L for a boat from 17-20'.

http://www.karavantrailers.com/spec_sheet.cfm?photo=kc_bunk%2Ejpg

This trailer weight is 709, and well under the rating for the axle and tire installed.

Actually your forgetting the 15 - 20% load factor.

Axles are rated 2500, 3500, 5200lbs for standard use. We will assume he has a 3500 axle @ 20% safety factor for bounce and the extra force that is applied going down the road, so now he is at 2800 lbs, minus 700 for trailer weight, now at 2100lbs. He thinks he has 2750 lbs load, he is overloaded by 650 lbs.

My trailer has 2 - 5200lb axles, a plate rating of 9100lbs GVWR, minus 895 for trailer, I have a plate load (this is stamped on the manufacturers plate rating) of net capacity of 8200lbs, a far cry from the original 10,400 axle rating.

Now he can do as he wishes, we are just pointing out he is overloaded based on 1 - 3500 lb axle. If he wants to stay that way, I would recommend he weighs everything to know for sure.

[88fourwinns]

Adding a 2nd axle is a lot of expense, you have to change the whole spring mounting system, probably use different springs, buy 2 more wheels/tires, etc.

In this case if the frame is strong enough and if the trailer fits the boat right, adding a 5200 axle, with 15" rims + tires and 12" brakes would be the way to go, but it's expensive. Some companies do make single axle trailers with a 5200 axle like Load Rite, 5 Starr and Venture. The tandem will tow better but the single is much easier to maneuver in tight parking situations.

[yachtman]

88fourwinns wrote:
Adding a 2nd axle is a lot of expense, you have to change the whole spring mounting system, probably use different springs, buy 2 more wheels/tires, etc.

In this case if the frame is strong enough and if the trailer fits the boat right, adding a 5200 axle, with 15" rims + tires and 12" brakes would be the way to go, but it's expensive. Some companies do make single axle trailers with a 5200 axle like Load Rite, 5 Starr and Venture. The tandem will tow better but the single is much easier to maneuver in tight parking situations.

+1. Don't forget you will need also to remove purchase and relocate new fenders and all their mountings.

[BLCarl]

I spent some time at www.Etrailer.com when I was considering building a trailer. It was good because there was everything at one site. I was able to fill a shopping cart past my credit cards load limit. It might help you decide.

One nice trailer I was thinking about copying had the 2 axles attached to a angle iron subframe, Fenders and everything. Then the subframe bolted to the trailer frame. It was easy for him to move the assembly front to back to balance the load.

Another thought is the size of the wheel bearings. Beefing up the tires won't help the bearings much if you are really near the limit.

I understand your not from around here but Pacific Trailer offers a "rebuild Service" . They basicly fix it up for a price. Perhaps there is a local manufacturer in your area? Pacific will also sell the parts.

Boat trailers are not easy to find around here especially non rusty ones. In addition to trying to find one that is close enough to fit your boat. New ones are surprisingly expensive and adding good stuff like disc brakes,etc makes it even pricier. Unless yours is in bad shape I think it might be a good Idea to upgrade it.

Check out the prices

[2850Bounty]

I see that the OP has not posted back! Yes/no?

BLCarl wrote:


One nice trailer I was thinking about copying had the 2 axles attached to a angle iron subframe, Fenders and everything. Then the subframe bolted to the trailer frame. It was easy for him to move the assembly front to back to balance the load.

Another thought is the size of the wheel bearings. Beefing up the tires won't help the bearings much if you are really near the limit.

That would be the sub-frame that I mentioned earlier.

You'll now not only have the additional spring purches, but also the load sharing rocker arms, all which must have a fixed position on the sub-frame.



Good point on wheel bearings.

Five lug pretty much determines the smaller size spindles/bearings/hubs and even brake size.

Six lug gets you into a larger spindle/bearing/hub size and brake size.

.