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Considerations For Trailer Wheels & Tyres

There are millions of tires on the market, and they come with an array of designations and classifications. What are the best tires to use on my truck? This isn’t a stupid question .

In reality, the industry of tires can be like black magic with the many different names to help you stay in the right direction. When you go to the tire shop they whirl away the letters and numbers in such a speed that your head spins. Are I really interested in that? Would I look stupid if I ask many questions? Although it might be daunting, aren’t going to look foolish asking questions. You’re learning and that’s crucial.

The biggest issue with tire shops is the people who interact with sales representatives. Their task is to help you get out of the door with brand new tires. It is best if they offer you the tires they have on hand Add a lengthy warranty, and you’re finished. That’s a bit out of line with your goal to get the tires that will work most effectively in the long run. For that reason, in order to get the best tires you need to know what you are doing.

A knowledgeable client is a better one to deal with. If you’re prepared, it’s more likely you’ll walk out with the correct tires. So, let’s take a dive for a moment.

First, Tire Designations

Tires come in a myriad of of classifications but there aren’t any tires that have the same. To make space, we’ll focus on the most commonly used tire types, and point to Google for the more obscure ones.

The most commonly used method to define a tire is using this formula, which is also visible on the exterior sidewalls of the tire. The lettering is usually raised on the sidewalls of the tire with a shape like this:

(Service Type) (Width)/(Aspect Ratio) (Construction)(Rim Size) (Load Index)(Speed Rating) (Load Range) (Extras)


LT 215 75 R15 / 106Q 106Q BSW

Okay, so what do I do with this information? Don’t be too concerned about the finer details, since even tire experts need to research certain things. To keep you alert Sometimes, they make things a bit confusing or even leave some things out. Here’s how to understand the meaning.


Service Type — Passenger Car (P), Light Truck (LT), Trailer (T or ST), etc.. There are others however we’ll not worry about it right now. When it comes to trailers, we suggest LT and ST for the majority of trailers. Check out Tires for Trailers Tires as well as Automotive Tires for further details. Small tires may have distinct names, but we’ll leave the subject for later.

Width — The nominal tires width measured in millimeters, from the bulging edge to the bulging edge. It’s not the width of the tread nor is it the width of the bulge due to the weight of the vehicle that is resting in the street. The tire’s width is “theoretical” broadest part of the tire, when fully inflated and sitting by it. (If you decide to measure the width of the tire, it’s not always precise.)

Aspect Ratio – This is a percentage of the height of the tire section to the width. This is the section of the tire not including the wheel. Take a look at the image. When you’ve got a 75-aspect ratio, then your distance between the edge up to the treads is approximately 75 percent from the length.

Construction — the makeup inside. Radial (R) is the only thing you require. Although there are other options, Bias ply tires are not readily available anymore for use in consumer applications. For applications on heavy trailers, there are sometires, however.

Rim Size The Rim Size is the diameter of the tire seat in inches. It must be equal to the rim. It’s not the complete outer diameter that the rim has. It’s interesting that the width of the rim isn’t a factor in the tire’s designation, however it is crucial when purchasing your tires and rims. Since the tire is a flexible and pliable, it’ll have an array of sizes to choose from something like 6.5 8” in width or some other. The rim will be stiff, so ensure that your tires fit the rims.

Load Index — This is a definition of the amount the tire is able to be able to carry, but it’s really an actual code. For instance, 106 indicates that it’s carrying at least 2094 pounds. It is all you have to do is find the index number, based on the capacity of the load you’re looking for.

Speed Rating is the speed that is the highest for the tire. It’s also an identifier that can be looked for. From the example above Q is a reference to speeds between 100 and 100 miles per hour. Because the majority of trailer tires are than L 75 miles per hour; M up to 81 mph, and N up to 87 mph, be sure that your tires are designed to handle the speed at which you travel.

Load Range — Once again it is a coded number that will indicate the ply’s as well as the maximum load rating for the tire. Normal Load (SL) Extra Load (XL) C D E, F, G, H, and perhaps with a number similar to one of “1” E1 for example. It’s not as significant to me, since it is the best way to pick the right tire.

Extras — Although there are some additional items that be seen at the end of the page but they aren’t all that crucial for their function. Things such as BSW (Black Side Wall) or the manufacturer’s codes, or even other things could be displayed.

And, Wheel Designations

Wheels (also known as rims) are much simpler. They are equipped with the capacity to load as well as a diameter, width as well as a bolt pattern as well as an offset. There are some that also have the pressure designation, however typically, it is part of the capacity to load.

Rim Diameter The tire’s seat diameter. This isn’t the total size of the tire. It’s a corresponding diameter that has to match the size of the tire. Rims come in various sizes that, on the one time define the wheelas the 14 or 15′ wheel. There’s more however this is the most important thing to consider.

Bolt Pattern A description of the number of bolts that are in the pattern of what size. The bolt pattern must be in line with the pattern of the axle. It’s typically described with the format 5 on 5”, or similar to that. It can be identified as 5 holes on 5″ (bolt circular) diameter, evenly spaced. Wheels with higher capacity are equipped with more holes on diameters, referred to as a “Bolt Circle Diameter”. Examples include 6 on 5.5″ or 8” on 9″” diameter.

Width Rim width is the area between the flanges, where the tire is. This is a dimension that is linear such as 7”, and it must be within the acceptable limits for the size of tire. A wider rim will allow the tire to have more “bulge”. Wheels made for trailers are more likely to be shorter side to provide more clearance. Make sure that the specifications of the tire match with the wheel’s width, diameter and load capacity.

Offset The offset is typically at a zero value for the trailer wheel. Offset is the distance that is measured from in the middle of the wheel towards the mounting surface. It is sometimes referred to as “Dish”. For Front Wheel Drive cars, they feature offset “out” which allows the shafts of the axle to have more space inside. Dually-equipped cars have a huge offset, allowing wheels to bolt together while leaving space in between tires. If you choose wheels that have offsets other than zero may permit the tires to “stick to the road” or “pull into” slightly. It is not a common practice with trailers as it forces the axle bearings slightly different , which decreases the axle’s capacity for load. We suggest sticking with Zero Offset to avoid trouble.

Choosing Your Trailer Tires

Once we’ve got the important information taken care of Let’s get more specific about tires that are suitable for your trailer. Certain tires are not suitable for an enclosed trailer. Of course, you could use the high aspect ratio, wide tires on the trailer if you like or to complement the tow vehicle in a display. These are always interesting to observe. But, in a pragmatic sense, it is possible to find a lot of which we can eliminate.

Did you know? You can find a great selection of 10 inch trailer wheel over on this website…

Size Matters to Take into Consideration

In general the smaller wheel diameters have smaller diameter tires and can carry less weight. However they provide smaller trailers and lower vertical intrusion over (smaller wheel wells, fenders and fenders, etc. ) however they also have less clearance from the ground.

In general, larger tires are able to carry more weight. While having a bigger footprint is beneficial in certain ways, they require some extra space from between the sides. If you frequently drive on rough terrain — such as the lawn, deep gravel , or sand, larger tires can be beneficial.

Pressure on tires can be an issue, especially in the event that you drive your trailer with empty. Bounce of the trailer is a real issue and pressure is one method of dealing with it according to this article on bounce on the trailer. Smaller tires that have high pressure are especially susceptible to. Selecting tires with a higher Aspect Ratio (like 75 or 80) will help because they have more sidewalls that can provide some “suspension” impact.

Speed and Load

It is important to know that the Speed Rating and Load Index numbers are more than simply what’s appropriate and safe. Do not skimp on either. If you are unsure if you’ll ever be able to pull your trailer along the road, then you choose tires that are less than 75 mph. What happens when you need to drive and see that traffic is moving around you at speeds of 80+ miles per hour? Don’t be tempted to take it as a sign of weakness. My personal opinion is that there is no reason to think about a tire that has an octane rating less than N.

I think of Load Index the same way. While it’s simple to think of capacity of the axle converting directly to capacity of tires, you’re overlooking the way things are. Tires can be overloaded accidentally or through the dynamics (going around a curve). Because tire failures caused by trailers are not unusual and are not uncommon, it doesn’t seem sensible (to my mind) to go around with the minimum. I would recommend using tires that offer 10 percent to 15% more capacity. Check out this article for an illustration using numbers.

Simple Sense Problem Avoidance

If you can prevent the problem from occurring it’s better than resolving an issue later. Tires on trailers definitely fall in the bill. Tires and tire problems are the main reason for trailers towing issues when driving. Have we seen an unattended trailer on an open road, with no wheel? This is something you can avoid by taking the use of a few common sense actions.


Before all else, ensure that the tires are in good condition. If you notice dry rot, sidewall damages, or even extra bulges or wear unevenly Fix the issue prior to taking the truck off. If the axles aren’t straight, for example this can result in additional wear on tires. The wear is not the issue , but the process of creating heat with the wear that damages the tire’s core (which isn’t visible). The tire is weakened and, at the right time it’ll give way.

The way to avoid this is easy. Check your tires prior to you go. The majority of the time, the warning signs will be there before you know you when it is time to replace the tires on your trailer that are worn out. Another indicator is heat. Place your hand on the tires before you stop to fill up with gas. If the bearings or the tires are hot, find out why and repair it prior to moving on.


Check that your trailer is in good condition to receive the services you need. I have seen many trailers which are “probably” overloading. I’ve noticed even more when it comes to an axle problem that can cause tire overload . Learn about the proper load sharing of axles. It’s difficult to alter these issues at the moment however, you should know that you could need to modify your travel plans if the thing you’re trying to accomplish does not fit with the available equipment.

It’s the same about equipment that isn’t in good condition for the task.


Select trailer tires that have more capacity than you will need. I suggest 10 15% up to 15 percent or over. Here’s an example using numbers.

If you own an axle of 3500 pounds the wheel and tire should be able to handle at least 50% of the load (because there’s an end tire on each side of an axle). That’s 1750# capacity per. When you look at the charts the chart, the Load Index of 100 for 1764# is a good fit. Right? It’s not in my book. This model assumes that both axles are carrying the same amount of weight but rarely are the trailer loads exactly even. Additionally, when you go around a bend and the tire that is on the outside is carrying more simply due to the centrifugal force. If your tires are at the limit of their capacity, you will overload at every corner.

Naturally, the manufacturers design the tires that can withstand a certain amount of stress in situations such as bumps and corners on the road. However, when you’re pushing the limits it’s a sign of danger. There’s only an unimportant price difference when you buy tires that have 15% more capacity.

In the case of an axle with 3500lbs I’d increase the load by 15% on the 1750# to make 2012# the capacity of the tire that is the minimum. This is an Load Index of 105 for 2039#. It’s a straightforward method of avoiding problems.


Beyond the tires When you install the new ones on your trailer be sure that they fit properly.


While not specifically focusing on tires, ensure that your axle spindles are operating in a proper manner and that they are greased appropriately. Yes, it can take only a few minutes however, it is worth the effort to check them every couple of years, particularly in the event that the trailer is stored outside.

It’s actually quite simple. Jack the wheel up and turn it. Pay attention to it. If it is spinning well and there is no grinding or scraping sound then move on onto the next. Every couple of years, you must remove a hub and wheel to inspect the bearings and grease. If you own an RV or boat that can be used on the water, it is recommended to examine the bearings each season and maybe more frequently. If you take often or for long excursions, make sure you check the bearings frequently.

Does this seem absurd? Sometimes, the grease lasts for a long time. But, if it does fail, it’s typically catastrophic and it’s not a pleasant experience.


Check the brakes’ function every now and then.

There was a vehicle pulling an trailer in Idaho many years ago, with the brake locked. The hub was heated and wheel so much that the tire started to catch on fire. It caused a string of flames along the road, resulting in a massive forest fire. Horrible.

In another instance the wheel was pulled by me, with my “park brake” in place It took a couple of hours until it had cooled enough so that we were able to take the wheel out. The bearings were cooked to perfection and grease.

It’s a simple part of the regular check-ups and regular maintenanceor bring it to the repair shop for inspection.

Best of Luck with the Tires for Your Trailer

You don’t have to rely on luck. As previously mentioned that the most frequent problems are usually avoidable. Make sure you check and maintain your trailer regularly and be a bit over the top with the specs. You now know a second trick to ensuring that you are successful in towing your trailer.