What Is The Metric Size Conversion For The A78-13 ST Trailer Tire Size
Updated 03/28/2013 | Published 06/25/2010
Question:
I have a 1994 Spartan Elite boat trailer. It has Loadstar A78x13ST original? tires on it, and I want to replace them. Since A78x13 is no longer made, what would be an equivalent size I could use? There isnt a lot of room between the fender and the tire, so I wouldnt want to go any larger in circumference or width. Thank You.
asked by: michael r
Expert Reply:
The replacement size for the A78x13ST original tire is the ST175/80-13. The overall diameter is 24.1 inches and the overall width is 7 inches. You might want to measure on your trailer to make sure you have the clearance for the ST175/80-13 size.
The Loadstar ST175/80D13 Bias Trailer Tire with 13 inch White Wheel, # AM3S030, you have referenced is a bias tire on a 13 X 4-1/2 white wheel. The tire is a Load Range B, which means it is a 4-ply rated and has a maximum load of 1,100 lbs. at 35 psi.
You will want to check the maximum load on the A78x13ST tire you have to make sure you get the correct load rating for your trailer.
The ST175/80x13 size is available in a bias tire with a load range of B (1,100 lbs. at 35 psi), load range C (1,360 lbs. at 50 psi) and load range D (1,610 lbs. at 65 psi).
It also comes in a radial tire with a load range of C and a load range of D.
The difference in the bias tire and the radial tire is that the radial tire will give you a smoother ride than the bias tire and better stability with the newer, continuous rib tread design.
I am including links to the page of radial tires available in the ST175/80x13 size and a page of bias tires in that size. Also, I am including links to a couple of FAQ pages that will describe tire sizing and frequently asked tire questions.
Product Page this Question was Asked From
Loadstar ST175/80D13 Bias Trailer Tire with 13" White Wheel - 4 on 4 - Load Range B
- Trailer Tires and Wheels
- Tire with Wheel
- Bias Ply Tire
- Load Range B
- 175/80-13
- 13 Inch
- M - 81 mph
- 4 on 4 Inch
- Steel Wheels - Powder Coat
- Kenda
more information >
Featured Help Information
Miscellaneous Media
Continue Researching
- Shop: Kenda 4.80/4.00-8 Bias Trailer Tire with 8" White Wheel - 4 on 4 - Load Range C
- Shop: Loadstar ST175/80D13 Bias Trailer Tire with 13" Galvanized Wheel - 5 on 4-1/2 - Load Range D
- Shop: Roadmaster Hitch Spare Tire Mount with 2" Receiver Opening - 2" Hitches
- Shop: Karrier ST175/80R13 Radial Trailer Tire with 13" Galvanized Wheel - 5 on 4-1/2 - Load Range D
- Shop: Loadstar ST175/80D13 Bias Trailer Tire with 13" Galvanized Wheel - 4 on 4 - Load Range C
- Shop: Vesper Steel Modular Trailer Wheel - 16" x 6" Rim - 6 on 5-1/2 - Silver
- Q&A: Replacement Trailer Tire for an Old A78-13 Tire
- Shop: Trailer Hitch
- Q&A: Lug Nut Torque Chart for Trailer Wheels
- Article: Trailer Wiring Diagrams
- Search Results: trailer hitch
- Shop: Curt Powered Tail Light Converter with 4-Pole Flat Trailer Connector
- Video: Measuring To Choose The Right Trailer Axle
- Shop: Trailer Wiring
- Q&A: Comparing Kenda KR03, KR35, And KR53 Tires
- Search Results: trailer tires and wheels
- Article: Brake Controller 7- and 4-Way Installation Kit (ETBC7)
- Video: Hands-On with the Hub Saver Hub and Wheel Protector
- Shop: Suspension Enhancement
- Q&A: Which is Better for Highway Use 4.80-12 or 5.30-12 Trailer TIres
- Search Results: trailer jack
- Article: How to Measure Your Trailer Wheel Bolt Pattern
- Search Results: trailer wiring
- Q&A: What is the Difference Between Load Range C and D ST175/80D13 Trailer Tires
- Article: How to Measure for Trailer Hitch Drop
- Shop: Brake Controller
- Q&A: Difference Between Trailer Tire Sizes ST205/75R15 and ST225/75R15
- Video: Review of etrailer Trailer Hubs and Drums - Hub with Drum - AKHD-545-35-EZ-K
- Article: Wiring Trailer Lights with a 7-Way Plug (It's Easier Than You Think)
- Search Results: spare tire mount
on Trailer Tires and Wheels
Sean R.
3/3/2013
I just replaced my old trailer tires, date code 2002.The old ones were Nanco A78-13ST but right on the tire next to the size numbers it says Replace ST16580-13. I have verified that these were the correct original tire size for my trailer 1991 ShoreLandr B1715.I replaced with Nanco ST165/80D13 as stated on the old tire and can see that a 175 would not have probably fit as I already have tight clearances.My question is why does the old tire actually say replace with a 165 when every site I go to says the replacement is a 175?