Replacing tires: increase size from 14" to 15"?

[ekirkland]

I've got nearly 3,000 miles on my Jayco Whitehawk 27DSRL with Rainier tires. As we are planning a 5,000-6,000 mile trip this spring/summer to Utah, I'm considering buying new tires. The present ones look good; would you replace before such a trip? My present tires are 205/75R14's. I'm looking at Maxxis M8008's or similar if I stay with the 14" wheels. What will I gain, if anything, if I decide to replace the 14" wheels with 15" wheels? Have any of you gone this route and if so what wheels did you get? It would be nice to order tire and wheel already mounted and balanced. Thanks for any info.

[Lynnmor]

ekirkland wrote:

Lynnmor wrote:
You probably have 3500 lb. axles. That is, the springs, bearings, spindles, brakes and axle tubes are rated for 1750 lb at each tire location. My experience is that you are very lucky if these parts will even carry that much. But yes, at least get better tires.

How do I determine the axle rating?

The trailer will have a plate or sticker on it that will list the VIN number. The weight rating of the axle should be listed on that same plate or sticker. Also, the axle could have a tag or plate on it that will list the weight capacity.

You can also tell the weight capacity of the axle by measuring the diameter of the axle. Here is a list that will show the axle weight capacity based on the axle diameter:

Typical Axle Diameters Based on Axle Capacity
1,000-lb - 2,000-lb Axles: 1-1/2 inch - 1-3/4 inch diameter
3,500-lb Axles: 2-3/8 inch diameter
6,000-lb - 7,200-lb Axles: 3 inch diameter

If you can't find the information, post back with the numbers on the bearings.

[wa8yxm]

You failed to mention the age of the RV or if you did I missed it.

Trailers, if you incrase the wheel size it will generally increase tire life and raise the hitch a bit, (this (hitch) may or may not be a plus) It will also pull easier.

Motor homes.. It may roll a bit easier, but... You won't gain power.. MPH may or may not be affected... You will need to re-calibrate the speedometer.

Generally, a larger tire can handle a slightly higher load.. I increased tire size on both of my tires (Cost way less to do that back then).

[ekirkland]

Lynnmor wrote:
You probably have 3500 lb. axles. That is, the springs, bearings, spindles, brakes and axle tubes are rated for 1750 lb at each tire location. My experience is that you are very lucky if these parts will even carry that much. But yes, at least get better tires.

How do I determine the axle rating?

[Lynnmor]

You probably have 3500 lb. axles. That is, the springs, bearings, spindles, brakes and axle tubes are rated for 1750 lb at each tire location. My experience is that you are very lucky if these parts will even carry that much. But yes, at least get better tires.

[ekirkland]

I am mainly looking at increased capacity in that the present tires (max load-1760) barely exceed the trailer's GVWR of 7500. Going to a Maxxis M8008 ST205/75R15-8PR would give me 2150 per tire, but I'd have to buy new wheels. The Kumho 857 ST205/75R14 would give me 2271 per tire and would not require me to buy new wheels; I had Kumho's on my previous Casita camper and they performed well for 5 years. I'm curious about the Kenda tires; I also see they offer another ST tire in the Loadstar K550

[Sam_Spade]

JIMNLIN wrote:

The best part of the move it gets you away from a ST tire.

The OP did not mention a change of class or capacity in the proposed new tire. It is hard to guess at stuff like that if it's not mentioned. That is why I asked what his objective IS.

[JIMNLIN]

Moving from a 14" trailer wheel/tire to a 15" tire/wheel is one of the best upgrades you can do with a trailer if your trailer has room in the wheel wells for the upgrade.
The best part of the move it gets you away from a ST tire.

Depending on room in the wheel well and proper wheel pressure/wheel width requirements the Goodyear Wrangler HT in a LT235/75-15 C (50 psi) at 1980 lb capacity. Most LT tire makers carry this size.

And a Wrangler HT in a LT215/75-15 D (65 psi) at 2090 lbs capacity.

Maxxis LT U-168 is a commercial grade tire with several 15" sizes and have became popular with all types of trailer owners.

Vanco 2 from Continental another popular tire for trailer users has several 15" sizes and load capacities.

I see the Yokohama RY215 in a 700R 15 D at 2040 lbs capacity is popular on some of the other RV websites.

Goodyear Cargo G26 2249 lb capacity in a 225/70R 15 C 65 psi load range D for trucks/vans and trailers. The G26 also comes in a 195/70R 15 D load range.
Do your home work on the numbers.

Now if your wanting to stick with the 14" OEM wheel check out the Kumho 857 commercial class tires.

[allenm]

I'm planning on replacing my 14" Rainier tires with Kenda Karrier ST205/75R14 Radial Trailer Tires, Load Range D, 2,040 lbs (65 psi) this Spring.

[old_guy]

yes you might gain weight capacity if you go bigger. that's what I did and I don't egret it. I spent a lot of time on the side of the road with blow outs so I went to the tire dealer I know and told them enough is enough. haven't had a blow out since

[Bowfreak]

It should be easier to find a higher load rating on a 15" tire and the 15" will have a little less heat build up because of the bigger circumference.

[janechucknicode]

Actually I on't think you will gain any thing except height . And that is not enough to help in any situ. The cost of wheels and tires will over ride any thought of a gain,.
Your idea of the Maxxis are the best that I know of, I run about 12K a year and have not had a problem yet, EXCEPT of a bent axel.:M

And that has nothing to with tires ,,cept wear them out faster.
Get your Maxxis' they will treat you right.
That's my story and you know the rest.
Happy trails
Chuck

[Sam_Spade]

You will gain very little and it will cost a LOT.
The overall size of the tires might not be much bigger but it might be enough to rub on something.
What do you hope to gain ??

If the present ones "look good" why are you considering changing them ?? Do you carry a spare ? How OLD are the old tires ??