Trailer axle/tire question

[Skyco]

We're talking about tandem axles not duals.
The equalizers on tandem leaf spring axles insures the weight will be the same on both axles regardless of trailer loading. That is why they are called equalizers
Also you failed to consider the rotational torque under braking forcing more weight to the rear axle thereby making it the one with greater traction.
The equalizer is what causes this action. Independently sprung systems (no equalizer) operate completely differently.

 

[pat32rf]

Up here any trailer over 2000lb must have brakes, and if its a tandem it shall have brakes on BOTH axles, not just the one with the flat tire!! ;-)

 

[LBrown59]

1*To mandate that all trailers have dual axle brakes is trying to require things that aren't always necessary, just because in your case they are.
2*If dual axle brakes were always needed, there would be no single axle trailers on the road.
David from jax

1*I'm not advocating that all trailers have 4 brakes ; but that all trailers have brakes on all wheels.
2*that's fine if the trailer has just 2 wheels.

 

[Wis Bang]

The first question is 'Does the suspension use the equlizer system or are the two axles sprung independently?' I would suspect that an independent system might shift the weight to the froward axle while the equalizer would do the opposite. Independently sprung axles would also cause different frame stress points and would require different re-inforcement in the design process as well as different behavior when crossing dips and other un-even pavement situations.

I'd start visiting places w/ trailers on display and start looking how the manufacturers do it. You can pace along side a trailer and get a feel for how the axles are spaced, etc.

Also make sure you understand why they gusseted some areas and not others & make sure you have good penetration on your welds.

 

[David Devuono]

I have built a few trailers, Only one twin axle which I put two braked axles on. I have checked out a lot of custom trailers from the Jeep-trailer queen types. I think a lot of the front axle\rear axle brake discussion should keep in mind the method of springing the axles. Weight bias moves forward during braking so if you were using axles bolted solidly to the frame or Torsion axles, you would likely put the brakes on the front axle. If you are using conventional spring axle with an equalizer, as the front axle dives, it forces the rear axle down. This lifts the front axle and you loose a lot of the braking effort. If you add the brake to the rear axle, you will have more braking effort as it will carry more of the load as its forced down? Makes sense to me now that I think of it.

 

[David Devuono]

Wis Bang, you type faster then I.

 

[David Devuono]

So as I am getting ready for my first trailer pull this spring I was going to check the brake adjustment as it seems one axle locks up before the other. Now I understand I would be wasting my time and will investigate the resistor idea, or live with constantly adjusting the trailer from the brake controller?

 

[Wis Bang]

We're talking about tandem axles not duals.
The equalizers on tandem leaf spring axles insures the weight will be the same on both axles regardless of trailer loading. That is why they are called equalizers
Also you failed to consider the rotational torque under braking forcing more weight to the rear axle thereby making it the one with greater traction.
The equalizer is what causes this action. Independently sprung systems (no equalizer) operate completely differently.

Close, the equalizer lets the axles move with the teraine conditions while allowing the weight of the load to be equalized between the axles. Examine the setup on a tractor trailer, the spring ends hook into the equalizer and the outboard ends float in the spring hangers and the 'torque arms' keep the axles in position. Utility trailer axles use shackles instead of floating the spring ends. Equalizing the weight on both axles prevents overloading the frame.

 

[Skyco]

Ok for all you doubters I emailed the two leading axle manufacturers, Dexter and Alko, with the question of which axle on an equalized leaf spring system gets the brakes.
Not surprisingly both recommended both axles but said if only one axle gets brakes it should be the rear.
BTW they both answered on the first business day, I'm impressed.

 

[sandman2234]

Dexter makes good stuff, and stands behind it, last I purchased. Haven't done any with the other manufacturer you mentioned.
I still disagree with lbrown, in saying all axles should have brakes. Depends on what you do with it. If a single axle trailer will work, and you opt for a dual axle just because you hate to overload the p.o.s. tires they put on them nowadays, then single axle brakes should be fine. Pulling lawnmowers is an example, on a 6x12 foot single axle trailer. Add a second axle just to make it pull better going down the road, and why should you have to add brakes? If you say something, then you have to figure all of the angles, or your just spitting out bull.
David from jax