Common Questions People Ask About Tires on a Flatbed Trailer

Neighbors Trailer

Dec 15, 2023
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6 min read
Flatbed Trailer Renta

Flatbed trailer tires sit at the bottom of every safe haul. They carry the weight, absorb the road, and decide how confident you feel pulling a heavy load down the highway. Yet most owners learn about them the hard way, on the shoulder of an interstate with a blown sidewall and a tow truck on the way.

This refreshed guide answers the questions flatbed owners ask most often: what to buy, how to size them, how much pressure to run, and how to spot a tire heading for trouble before it strands you. Whether you tow a deckover for a side hustle or rent your flatbed out on a peer-to-peer marketplace, the answers below will help you keep miles on the clock and your cargo on the deck.

Trailer Tire Types: What Belongs on a Flatbed

Tire selection is the single most common mistake new owners make. Passenger and light truck tires look similar in the bay, but they are engineered for a completely different job. Trailer tires, marked with an "ST" prefix, have stiffer sidewalls and a load-first construction that keeps the trailer planted in turns instead of swaying behind your tow vehicle.

Radial vs. Bias-Ply

Radial ST tires use steel belts running at 90 degrees to the tread, which puts more rubber on the ground, runs cooler, and lasts longer on highway miles. Bias-ply ST tires use overlapping diagonal plies for a stiffer sidewall, which favors heavy short hauls and rough job-site duty. Most modern flatbed owners run radials for the lower running temperature and the better fuel economy over long trips.

Why Not Light Truck (LT) Tires?

LT tires are built to steer and drive, not to be dragged. They flex more in the sidewall, which feels fine on a pickup but causes trailer sway, uneven wear, and dangerous handling on a fully loaded deck. Stick to ST-rated tires sized correctly for your axle, and the rest of the trailer behaves the way the manufacturer intended. If you want a deeper walkthrough of selection, our guide on how to choose the right tires for your trailer covers the math in detail.

Reading the Sidewall: Size, Load, and Speed Codes

Every ST tire prints its specs on the sidewall in a fixed format. Once you can read it, choosing replacements is much faster. The example below is the most common flatbed size in North America.

Code Segment	What It Means	Example (ST225/75R15 117L)
ST	Special Trailer service	ST
225	Section width in millimeters	225 mm
75	Aspect ratio (sidewall % of width)	75%
R	Radial construction	Radial
15	Wheel diameter in inches	15 in
117	Load index (lbs per tire)	2,833 lb
L	Max speed rating	75 mph

Always match new tires to your trailer's GVWR. A four-tire axle pair rated at 2,833 lb each gives you 11,332 lb of tire capacity, which should sit comfortably above your fully loaded weight.

Pressure: The Free Performance Upgrade

More flatbed tire failures come from under-inflation than from tread wear. ST tires are designed to run at their max sidewall pressure when loaded, which is much higher than what people are used to from passenger tires. The chart below shows typical cold pressures by common ST size.

Typical cold tire pressure in PSI for common ST trailer tire sizes from ST175 to ST235

NeighborsTrailer.com

Check pressure cold, before the first miles of the day, and check before every long trip. A 10 PSI drop on a fully loaded ST tire builds up enough heat at highway speed to delaminate the tread inside an hour.

Maintenance Habits That Add Years to a Tire

ST tires usually fail from age before they fail from tread wear. A flatbed that only sees occasional weekend use can still age out in five to seven years. The habits below add the most life per dollar.

Cover the tires when the trailer sits, especially under direct sun. UV breaks down rubber faster than rolling miles.
Rotate side to side every 6,000 to 8,000 miles to even out shoulder wear from highway crowns.
Inspect for hairline cracks at the sidewall and between tread blocks every time you hook up.
Get bearings packed on a regular schedule. Bad bearings cook a tire from the inside.

For the full seasonal routine, our guide on extending tire life is worth a read.

Seasonal and Damage Questions

Do I Need Winter-Specific Trailer Tires?

In states that see real winter weather, dedicated winter ST tires improve traction on ice and packed snow. They also stay flexible at low temperatures, which standard ST compounds do not. If you only tow occasionally in cold weather, all-season ST tires are a reasonable compromise. Owners in Canada or the northern Plains often switch to dedicated winter tires for the season.

Can a Punctured ST Tire Be Repaired?

A clean puncture in the tread, away from the shoulder, can be plug-and-patched by a qualified tire shop. Sidewall punctures, bulges, or cuts that reach the cords are replacement-only. ST tires carry stresses passenger tires never see, so a marginal repair will not hold up.

How Should I Store Tires Off-Season?

Inflate to max sidewall pressure, set the trailer on blocks so tires are unloaded, cover them, and keep them in a cool dry space away from ozone sources like electric motors or welders. Done right, a stored ST tire will outlast a tire that rides on a parked trailer all winter.

What This Means for Owners and Renters

If you own a flatbed, the tire program is the highest-leverage piece of maintenance you can run. Proper ST tires, matched to the trailer's GVWR, kept at the right pressure, and replaced on age, will pay for themselves in fewer roadside calls and longer rental seasons. If you list a flatbed on a peer-to-peer marketplace like Neighbors Trailer, well-maintained tires are also what move a listing from "fine" to "fully booked," because experienced renters can spot a tired tire in the parking lot.

If you rent rather than own, do not skip the walkaround. Check pressures, look for cracking on the sidewall, and confirm the load rating exceeds your planned cargo weight. A two-minute inspection at pickup is the single best safety habit you can develop.

Content updated May 2026