Size of 2020 Rockwood mini lite 2109s tires

[1ed]

I would like to know the size of the tires on a 2020 Rockwood Mini Lite 2109S.
Thanks Ed

[6CatDaddy]

Since no replies yet, our 2019 model 2109s has ST205/75R14's.
Castle Rock ST's.
We have about 2200 miles on them... Ikeep up on the air pressure (65lbs) and I ck on them throughout a trip...
I want to replace them with GY Enduance but, so far, the OE's are doing ok... I know of all the China Bomb stories, but... there are also a lot of owners who have not had issues...
Don't know if I should or shouldn't change em out.

Standing by for flaming responses.

[Jay2504]

6CatDaddy, are your tires load range C orD?? I have the same 205/75/14, load range C on our 2504s, which I would imagine is heavier than a 2109s. Jay..

[dicktracy]

Our 2018 2109s has Castle Rock ST 226 ST205/75R14 Load range C

[67L48]

Originally Posted by Jay2504

[...] I have the same 205/75/14, load range C on our 2504s, [...]

This would be more helpful with details -- year matters. I recommend putting your RV and TV in your signature to eliminate the ambiguity.

My 2018 2504S has Castle Rock ST205/75R14, load range D.

[Jay2504]

Good idea. I actually never thought of doing that. My unit was built 12/15, I bought it on 2/16. Jay

[01tundra]

Our 2020 2109s came with 205/75/14 Castle Rocks, stopped on the way home from purchasing and had five GY's of the same size (but Load Range D) and steel valve stems installed.

[67L48]

It's a bit of a weird deal, because Castle Rock Tires doesn't even list an ST215/75R14 D Load tire in its tire chart. So, when I read a few weeks ago about someone discussing his ST215/75R14 D Castle Rock tires, I immediately thought, "WRONG! Such a tire doesn't exist!"

Yet, then I looked at my own tires and, sure enough, they are Castle Rock ST215/75R14 D tires at 2,020 lbs of capacity.

At some point in the ~2017-ish range, it appears that the larger (26' slide-out models) Mini/Micro Lites went from C to D. The smaller ones may have stayed at C throughout. Not sure.

And, I'm not sure if the new 2020 large ones still have D or if the current tires chart I linked to above is accurate/comprehensive ... and all ST215/75R14 tires from CR are now C. Again, I'm not sure.

I know this: these trailers have a GVWR of ~6,800 lbs. If 12.5% of that weight is on the hitch, then about 6,000 lbs are on the axles. Four tires for 6,000 lbs is about 1,500 lbs. So, you need tires to support 1,500 lbs.

C rated tires are 1,760 lbs. So, they give you 7,040 lbs of capacity. That's about 800-1,000 lbs more than you'll need, depending on how you load the trailer. So, that's why these trailers had been equipped with C tires. Technically, that's enough capacity to support the GVWR.

D rated tires are 2,020 lbs. So, they give you 8,080 lbs of capacity. That's about 1,800 - 2,000 lbs more than you'll need. So, people like me have an atrocious amount of margin between trailer weight and tire capacity. I'm bending axles and frames before I overload my tires. This could be deemed overkill and, in a margin-tight industry, may be why a company would look to scale back to C at some point.

The larger 215 D rated tires are 2,200 lbs. So, they give you 8,800 lbs of capacity. That's approaching 3,000 lbs of excess capacity ... or 50% more than your trailer's GVWR.

When pushed hard, I would expect Castle Rock to fail earlier than GY Endurance. But, when I'm using ~67% of the tire's capacity, I'm less worried. Maybe that's false reassurance based on a faulty premise, though.

Enjoy.

[rockfordroo]

Originally Posted by 67L48

It's a bit of a weird deal, because Castle Rock Tires doesn't even list an ST215/75R14 D Load tire in its tire chart. So, when I read a few weeks ago about someone discussing his ST215/75R14 D Castle Rock tires, I immediately thought, "WRONG! Such a tire doesn't exist!"

Yet, then I looked at my own tires and, sure enough, they are Castle Rock ST215/75R14 D tires at 2,020 lbs of capacity.

At some point in the ~2017-ish range, it appears that the larger (26' slide-out models) Mini/Micro Lites went from C to D. The smaller ones may have stayed at C throughout. Not sure.

And, I'm not sure if the new 2020 large ones still have D or if the current tires chart I linked to above is accurate/comprehensive ... and all ST215/75R14 tires from CR are now C. Again, I'm not sure.

I know this: these trailers have a GVWR of ~6,800 lbs. If 12.5% of that weight is on the hitch, then about 6,000 lbs are on the axles. Four tires for 6,000 lbs is about 1,500 lbs. So, you need tires to support 1,500 lbs.

C rated tires are 1,760 lbs. So, they give you 7,040 lbs of capacity. That's about 800-1,000 lbs more than you'll need, depending on how you load the trailer. So, that's why these trailers had been equipped with C tires. Technically, that's enough capacity to support the GVWR.

D rated tires are 2,020 lbs. So, they give you 8,080 lbs of capacity. That's about 1,800 - 2,000 lbs more than you'll need. So, people like me have an atrocious amount of margin between trailer weight and tire capacity. I'm bending axles and frames before I overload my tires. This could be deemed overkill and, in a margin-tight industry, may be why a company would look to scale back to C at some point.

The larger 215 D rated tires are 2,200 lbs. So, they give you 8,800 lbs of capacity. That's approaching 3,000 lbs of excess capacity ... or 50% more than your trailer's GVWR.

When pushed hard, I would expect Castle Rock to fail earlier than GY Endurance. But, when I'm using ~67% of the tire's capacity, I'm less worried. Maybe that's false reassurance based on a faulty premise, though.

Enjoy.

For another point of reference, on my Mini Lite 2503S, my C rated Constancy ST205/75R14's are rated for 1984 lbs.

At a GVWR of 6583 lbs and 12% TW, they're loaded to 72%.

At actual weight, they're loaded to about 61%.

[72guy]

I’m looking at purchasing a 2020 2509S. Has anyone looked into upgrading their tire/wheel combination to 15” or 16”? Is there adequate space in the wheel well or between the axles/tires to mount a larger tire? Thanks for your input.