How to Select Trailer Spare Tire with Adequate Weight Capacity

Updated 05/23/2017 | Published 05/22/2017

Products Featured in This Question

Karrier ST205/75R14 Radial Trailer Tire with 14" White Wheel - 5 on 4-1/2 - Load Range C

(1558)

$175.86

Karrier ST205/75R14 Radial Trailer Tire - Load Range D

(2247)

$140.51

Question:

My single axle travel trailer did not come with a spare tire, I understand the difference between the bias ply and radial tires to an extent. Can a 205 75R14 cover the 3300# dry weight of my camper when loaded up its probably pushing close to 4000# the tires on it now say 205 75D14 with a 5 4 1/2 J rim and a speed rating of L. Thanks!

asked by: Marcus

Expert Reply:

Thank you for the photo of your ST205/75D14 bias ply trailer tire and its white mod style wheel. You definitely want to use the same size tire for your spare as you have for your primary tires and while you could use a radial as a spare even though you have bias ply tires on the trailer I suggest staying with the same tire type. If in the future you change the trailer over to radials then by all means you can also use a radial as a spare.

Trailer tire weight ratings are expressed as a letter code, such as Load Range C, or LRC as it might appear on a tire. Although it does not show in your photo your tires will have a load range rating of B, C or D indicated on the sidewall. You want to select tires based on the trailer's GVWR, its gross vehicle weight rating, as this is the most the loaded trailer can safely weigh.

A wheel/tire similar to yours rated for Load Range C (1760-lbs) is part # TTWA14RWS. This combines a 14-inch white spoke wheel with 5-on-4-1/2 bolt pattern with a LR C bias ply tire rated for 1760-lbs. This is shown on the linked wheel/tire page.

But you can always choose a separate wheel and different tire and have them mounted together locally. For a white spoke wheel # TTW460545WS1 has the 14 x 6 size you need. If you need tires that can handle 2200lbs each, then you will want to use Load Range D radial tire # AM10235.

Please note that BOTH the wheel itself and the tire itself must be rated for the load you will put on them. A tire rated for 2000-lbs on a wheel rated for 1870-lbs means the combination has the capacity of the lower-rated component.

Please feel free to tell me your trailer's GVWR and I will be glad to help you select a spare. Links to tires, wheels and combination products are provided for you, along with some helpful articles.

expert reply by: Adam R