Rv axle rating decision

Are you talking bout an upgrade choice?

I would find out exactly what the upgrade entails. For example:


Beefier mounts to the frame?
A cross brace?
Bigger brakes?
Wheel lug pattern?
Tire Size?
Bigger wheel bearing?
Is there an option to match trailer bolt pattern to tow vehicle?
Is there a GCWR increase?

etc.

If normal is 6K I would be very careful getting 8K. The springs will be so stiff everything in the trailer will take a beating. Going up one size is usually good, any more than that gets questionable.

graypark wrote:
I am early on in the buying decision for our first fifth wheel. My question is whether or not to insist on 8000lb rated axles, irrespective of the GVW of the particular rv. Should this be a "must option" or look for one with these as standard equipment.

There's more to axles than just their rating. Say you compare 6000 lb axle to 8000 lbs axle, likely to require different wheels and tires, and the 8000 axle wheels/tires may not fit on a trailer designed for 6000 lb axle wheel/tire combos. How big is this 5th wheel you are considering? Make and model? ALWAYS have to consider the GVW.

Old-Biscuit wrote:
My 5vr came 'standard' with 6K axles and a GVWR 13,675#

I upgraded to the 7K axles which changed GVWR to 14,375#

Cargo carrying capacity remained the same.

IF 8k axles are an option.....go for it. Always better to have MORE axle and increase load carrying margin (amount axles really support) then be right at/closer to axle ratings....especially the suspension. (spring pack rating)


No reason this shouldn't be here....it is 'tech' in nature. But does it really matter

Interesting how the GVWR got raised. Many (all?) jurisdictions that can't be changed after-market so the axle upgrade was pre-original delivery?

With the cargo capacity remaining the same, and the GVWR going up by 700lbs, that means the trailer itself now weighs 700lbs more empty with the heavier axles. So what has been achieved? No increase in load carrying margin at all. Just more weight for the truck to deal with.

I do agree with upgrading the tire capacity in some cases where they take different weights each side and the total per axle is close to GAWR. This can mean one tire is overloaded at GAWR. However that has nothing to do with the axle ratings.

Mostly the trailer has a certain frame strength, hitch strength, axles, tires etc etc and it is all supposed to be fine the way it is. If you don't like its specs, there are lots (pun!) of others to choose from.

Weight threads are hopeless! :( Nobody ever convinces anybody. Like trying to tell RJ his PD converter isn't the best ever :)

BFL13 wrote:
What for?

Probably for the same reason many RVers upgrade their tires with a higher ply rating than what comes standard. For an extra margin of safety.

My 5vr came 'standard' with 6K axles and a GVWR 13,675#

I upgraded to the 7K axles which changed GVWR to 14,375#

Cargo carrying capacity remained the same.

IF 8k axles are an option.....go for it. Always better to have MORE axle and increase load carrying margin (amount axles really support) then be right at/closer to axle ratings....especially the suspension. (spring pack rating)


No reason this shouldn't be here....it is 'tech' in nature. But does it really matter

I would opt for the HD axles, tires & wheel package if it was a normal option.
Otherwise you are mostly going to be accepting the trailer as built.

graypark wrote:
I am early on in the buying decision for our first fifth wheel. My question is whether or not to insist on 8000lb rated axles, irrespective of the GVW of the particular rv. Should this be a "must option" or look for one with these as standard equipment.

What for? The trailer is designed as being a certain weight and able to carry more weight up to its GVWR. Getting higher weight rated axles (heavier no doubt) just eats into your available cargo weight before you hit the GVWR. If you don't trust the designer of that trailer, don't buy it.

This actually belongs in the 5er forum.

Have never had a problem with my 7K axles under my 13,500 pound scaled fiver. I guess it depends on how big of a fiver your considering. With 8K axles you should also insist on disc brakes and 17.5 inch wheels.