14" vs 15"

[bigb56]

I believe the Imagine xls trailers come with 14" tires. The regular Imagines come with 15". .So if we buy the xls 22RBE like we plan to the tire choices are pretty limited, and the load range is limited to "D". The Imagine 2150RB is practically the same weight as the xls by a couple hundred lbs yet it comes with 15" tires. I am wondering if it would be worthwhile to upgrade to 15s even if it means a lift kit. Or maybe the "D" rated tires will be just fine on a 6,500 GVW trailer? FWIW I am religious about tire maintenance and inspection.

[MidwestCamper]

I believe the Imagine xls trailers come with 14" tires. The regular Imagines come with 15". .So if we buy the xls 22RBE like we plan to the tire choices are pretty limited, and the load range is limited to "D". The Imagine 2150RB is practically the same weight as the xls by a couple hundred lbs yet it comes with 15" tires. I am wondering if it would be worthwhile to upgrade to 15s even if it means a lift kit. Or maybe the "D" rated tires will be just fine on a 6,500 GVW trailer? FWIW I am religious about tire maintenance and inspection.

You will need to see what tire clearance you have to make a choice in moving forward. I have an Imagine that came with the ST205 75R15 D and moved to a ST225 75R15 E where I lost 0.5 inch of clearance. Before making the move I had discovered my original tires had struck the floor, so I added a one inch lift among other improvements and have been happy. I ran the Westlake tires for two seasons, sold them and purchased Goodyear Endurance tires for piece of mind. Also looking at the Goodyear inflation chart their ST215 75R14 tire has a higher load capacity than the ST205 75R15 tire so there is some overlap on load capacity.

[bigb56]

You will need to see what tire clearance you have to make a choice in moving forward. I have an Imagine that came with the ST205 75R15 D and moved to a ST225 75R15 E where I lost 0.5 inch of clearance. Before making the move I had discovered my original tires had struck the floor, so I added a one inch lift among other improvements and have been happy. I ran the Westlake tires for two seasons, sold them and purchased Goodyear Endurance tires for piece of mind. Also looking at the Goodyear inflation chart their ST215 75R14 tire has a higher load capacity than the ST205 75R15 tire so there is some overlap on load capacity.

Thanks, just what I was looking for. I had my eye on the 15" 225 tire as well. On the chart it does not show as an E rated tire till 80 PSI, does this mean it's the same tire all the way across the chart but doesn't support an E rating till it gets 80 PSI?

[MidwestCamper]

Thanks, just what I was looking for. I had my eye on the 15" 225 tire as well. On the chart it does not show as an E rated tire till 80 PSI, does this mean it's the same tire all the way across the chart but doesn't support an E rating till it gets 80 PSI?

The tire is an E rated tire based on its construction and its ability to handle the higher pressure to support a higher load. Looking at the chart you could inflate this tire to 50 psi to support the same 2150 lbs that the ST205 tire would be at fully inflated at 65psi. This is due to the tires heavier sidewall construction which contrary to some, provides additional support. But we want a higher safety factor so I fill to the same 65 psi where I have the additional load carrying capacity but I am also not at the tires maximum capability. You can always run at the maximum side wall pressure of 80 psi on the ST225 tire but your suspension and chassis will take a pounding. To be sure it would be best to weigh the RV fully loaded off an on the truck (with bars) and side to side to be sure the proper inflation pressures are used. Also purchase a good quality TPMS system to monitor your tires pressure and temperature while traveling.

[bigb56]

The tire is an E rated tire based on its construction and its ability to handle the higher pressure to support a higher load. Looking at the chart you could inflate this tire to 50 psi to support the same 2150 lbs that the ST205 tire would be at fully inflated at 65psi. This is due to the tires heavier sidewall construction which contrary to some, provides additional support. But we want a higher safety factor so I fill to the same 65 psi where I have the additional load carrying capacity but I am also not at the tires maximum capability. You can always run at the maximum side wall pressure of 80 psi on the ST225 tire but your suspension and chassis will take a pounding. To be sure it would be best to weigh the RV fully loaded off an on the truck (with bars) and side to side to be sure the proper inflation pressures are used. Also purchase a good quality TPMS system to monitor your tires pressure and temperature while traveling.

Thanks, I can see I will have a lot of homework to do concerning lift amount. I also want to do the Moryde suspension kits with wet bolts for the leaf springs and yes definitely a TPMS as soon as I figure out which brand and screen color/no color, flow thru/non flow thru etc. Leaning toward TST with grayscale screen but not sure on the flow thru vs non flow thru just yet. I am also curious about the extra steel TucsonJim added to his wheel wells for extra protection in case of a tire failure. I'm sure though that Jim would rather never have the opportunity to know if they helped.

[MidwestCamper]

Thanks, I can see I will have a lot of homework to do concerning lift amount. I also want to do the Moryde suspension kits with wet bolts for the leaf springs and yes definitely a TPMS as soon as I figure out which brand and screen color/no color, flow thru/non flow thru etc. Leaning toward TST with grayscale screen but not sure on the flow thru vs non flow thru just yet. I am also curious about the extra steel TucsonJim added to his wheel wells for extra protection in case of a tire failure. I'm sure though that Jim would rather never have the opportunity to know if they helped.

Bigb56,
Several of us have done this whether buying a kit or making the blocks up at home. Here are a couple pics of my Imagine solution. For TPMS and if I had to do it over again since I purchased replacement tires, I would buy the integrated sensors since the valve stem mounted external models are sort of a hassle to add air.

[Leon T]

FWIW - I bought a 20' Load Trail flatbed trailer years ago that had 14's on it. I questioned the dealer about this and he said to try them and if I didn't like them he would swap to 15's for free. He said a little lower profile and easier to load things. He was right. I have run that trailer many thousands of miles now with 14's hauling cars, tractors, alfalfa bales and everything in between. I know I've had it overloaded many times. The last set of tires I put on it were D rated and I have only had one blowout (a crappy Green Dot tire from Discount) in all the years I've owned it.

In short - I wouldn't be the least bit afraid of 14" tires. I was initially skeptical like you but time and experience have now taught me otherwise.

[TimtheToolMan]

Friday at a trade show a GD representative said that larger tires will not work on 22MLE or 22RBE (not sure which) because they are too wide and that modifying suspension would void warranty. He did not say what size or width that he was talking about.

Are the stock tires side wall pretty close to something? Could this be related to having clearance for mud or snow buildup on the tires.

Jim's mentioned lift design looks like a good way to gain clearance above tire.