Walk Thru New Bigfoot

[JimKE]

Josh, it should be stamped on the inner rim side. I have a 2008 Bigfoot and the rims were max 55PSI. Tire people said they would withstand higher! Ha! LOL!
I put new higher pressure rims on and went with Goodyear Endurance Tires (made in USA) that have a higher PSI rating. I didn't like the limitations of available tire selection at 55PSI rim rating.
However, that said, I ran Maxxis tires and they did well for me as well. This time around, I liked what I researched on Endurance and chose those.

Regardless, the advice you are getting here from others is rock solid!

[Josh and Sonya W]

Originally Posted by RV Doctor

Josh. I would recommend you try some different pressures in a lower, closer range to the manufacturer. Your trailer had GVWR of 7000. Today, my FB is 7500. My tire spec is same as yours but 35psi. Mine tows great at just under 40. Why not try 40-45? The problem with your pressures is that 80 cold can easily go over 110 in very hot weather or higher speeds. If you try 40, I think you will be safer and a smoother ride but still allowing a buffer. The other problem is at 80psi you are really wearing on the Center of the tread and getting premature wear there and insufficient road contact overall. Also uneven wear on the outsides of the tread.

Thanks Tony. A lot of things are beginning to make sense; the trailer does bounce around a lot on anything but really smooth roads. I looked at the tires today and I'm not seeing anything that looks like unusual wear after about 3,800 miles, so no damage yet.

I'm definitely going to go lower, think I'll start with 40 psi. Only hassle is reprogramming the tire pressure monitors. I opted for the inside-the-tire type, which makes programming a bit of a hassle with tires close together.

Thanks for all the good suggestions and data in this email chain!
Josh

[Josh and Sonya W]

Originally Posted by JimKE

Josh, it should be stamped on the inner rim side. I have a 2008 Bigfoot and the rims were max 55PSI. Tire people said they would withstand higher! Ha! LOL!
I put new higher pressure rims on and went with Goodyear Endurance Tires (made in USA) that have a higher PSI rating. I didn't like the limitations of available tire selection at 55PSI rim rating.
However, that said, I ran Maxxis tires and they did well for me as well. This time around, I liked what I researched on Endurance and chose those.

Regardless, the advice you are getting here from others is rock solid!

Thanks Jim, I'll pull off the spare tomorrow and see if I can find the rim pressure, but my guess is that you guys are correct about factory history. I've been running at 80 psi cold (and up around 90 and above at speed and in sun), and no failures (that I know of :>/ ) so far, so the rims have been able to take more than 55psi, but that doesn't make it a good idea, or more importantly, safe.

Josh

[Josh and Sonya W]

Originally Posted by Wacenturion

For those asking about Bigfoot weights, here is information on the scale weight of my Bigfoot 25FB, which should be close to a 25RQ. You can compare your trailer weight build sheet (located inside one of your cabinet doors) to mine.

Last year I had an opportunity to actually weigh the newly acquired and fully loaded 2008 30th Anniversary 25B25FB that I brought home from northern California in October of 2016. The build sheet shows a total dry weight with options at 5973.83 lbs. However my trailer does have the 2.5 kw Onan generator that wasn't on the build sheet which obviously weighs something. Mine also has the front storage which is listed in the option total with a weight of 116 lbs. The total dry weight is without water and propane in the tanks.
I have loaded it with 824 additional lbs of stuff (yes I actually weighed it all). So without actually weighing on a certified scale, my total weight would appear to be approximately 6797.83 lbs. Add in the weight of the generator's metal frame and generator itself underneath and I'm guessing close to 7000 lbs.
However after weighing it today I was plesantly surprised.......
Steer Axle..........3680 lbs.
Drive Axel..........5120 lbs. (44 gallon 2002 Excursion 7.3 diesel tank full)
Trailer Axel........6420 lbs.
Total Weight.......15220 lbs.
My 2002 Ford Excursion with a 7.3 Powerstroke has a 20,000 GCWR. I'm happlily 4780 lbs. under that combined rating. That gives me an honest 25% safety margin.

So in reference to the tire pressure discussion, if I ran at 35 psi, I would essentially meet the minimum weight requirement. My Goodyear Endurance ST225/75R15 tires at 35 psi (each tire 1760 lbs) for a total of 7040 lbs of support. I do not run the max cold psi of 65 psi only because my Bigfoot factory rims are rated at 55 psi, so that is what they are inflated to. That give a support rating of 2270 per tire, or a total of 9080 lbs., well above the minimum. Even if I load the dry tank up with water and some additional gear, I still have a good margin. As I said earlier, trailer pulls like a dream, tire pressure and temperatures on the road well within parameters with no towing hardness that I can tell.

Hi Dan,

I'm guessing that the 6,420 lb axle weight you gave is with the trailer attached to your truck and a weight distribution hitch engaged, is that correct?

So when figuring out the "correct" tire pressure, should that be based on the free-standing (detached) loaded trailer weight, or should it be based on the weight after being distributed to the truck by the WDH?

Thanks,
Josh