How to Determine Weight Capacity of RV with Higher Rated Suspension and Tire/Wheels
Question:
Someone asked about increasing the capacity of an RV travel trailer and you replied you can’t just do the tires, you need to do the axles, leaf springs and hubs as well. You also said to relocate the springs but not sure why on that one, cuz that takes it to another level and makes a much for difficult project! The question I have is we all know that RV manufacturers are very cheap and in more cases than I care to think about will actually use an axle rated several hundred pounds LESS then the certified weight!!! How that’s even possible and how they get away with it legally I’ll never figure out.. That said I’m wondering if y’all have any experience with the frame itself? I am going to be a full timer and some of these trailers only have an extra 750 pounds or so you can load on with personal belongings, which quite frankly is absurd. Barely gets you past filling up your water tanks! But I brought up them being cheap because if they cut corners there by using bare minimum ratings just to get by, than most probably they are cutting corners on the subfloor and framing as well. I guess what I am saying is I would hate to invest time and money upgrading the suspension just to find out the frame it self could bend or warp or contort or worse, BREAK when I’m done with the suspension work and throw on an additional 1000 pds with all the kind of good stuff I like to carry! Do the frames have any kind of a rating as well and if they do can it even be trusted knowing how crooked and sloppy the RV industry has become? And if there is no ratings on the frame or structure how can you tell what’s “too much?” Thanks and by the way you guys are absolutely awesome with every single aspect of your business :
asked by: Louis P
Expert Reply:
When you are talking about weight capacity you are limited to the least rated component in your setup. You are correct that the weight capacity of the frame needs to be taken into account as well as using tires, axles, leaf springs, and hubs with higher weight capacities. You can typically find the weight capacity of the frame itself stamped into the frame or on a sticker or label on the frame.
The reason that trailer manufacturers can rate their trailer weight capacities a little higher than just the axles is because some of the weight is transferred to the tongue of the trailer. At any given point the tongue weight (TW) is taking up either by your tow vehicle or a jack (or landing gear for 5th wheel and gooseneck applications).
If you cannot find the weight rating for the frame itself the best thing to do is contact the manufacturer and see if they can give you that information. Typically you will need to have your VIN ready when inquiring about specifics like weight capacity.
The reason behind needing to relocate your springs is that changing the weight capacity may actually change what your TW is. Since you want to keep your travel trailer TW between 10-15% of the weight of your trailer you may need to adjust where your axles sit to achieve this. I have attached a helpful article that goes over axle placement for you to reference.
Thank you very much for the kind words! Let us know if you have any other questions!
Product Page this Question was Asked From
Loadstar ST225/75D15 Bias Trailer Tire with 15" White Wheel - 5 on 4-1/2 - Load Range D
- Trailer Tires and Wheels
- Tire with Wheel
- Bias Ply Tire
- Load Range D
- 225/75-15
- 15 Inch
- M - 81 mph
- 5 on 4-1/2 Inch
- Steel Wheels - Powder Coat
- Kenda
more information >
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