How Fast For 12 Inch Tires

SweetLou wrote:

CapriRacer wrote:
First, 4.80-12 tires are restricted to 65 mph.

Second, 4.80-12 tires come in different load ranges: Load Range B - 785# at 60 psi, and LR C - 990# at 90 psi.

I'm going to guess the OP has LR B - and if that is so, then towing with 1500# is really marginal on load carrying capacity.

Also, there is a less than well known provision in the tire load tables that if you want to boost the max speed of trailer tires from 65 mph to 75 mph, add 10 psi. If you want to get to 85nph, also reduce the max load by 10%.

So the OP's original question? Like others, I would be more concerned about the tires than the bearings.

Agreed!. I am learning that the bearings won't be the issue. I can handle that with good synthetic grease and Timkins, however the tires will melt going 1500 miles one way with stops of course, then return trip. I think I will switch to passenger tires. The trailer is small, and the loads small as well, but the speed can safely be increased being a passenger tire. The load per tire will be rated around 900lbs which then will make it 1800 lbs. That trailer would never hold that weight so I am safe.

Before I came to this forum I was a member of a Gold Wing MC forum. Many, many guys are building their own cargo trailers using the little red Harbour Freight style trailer. The 4x4' size with 4.80x8 tires. Most just replaced the bearings or repacked them. Those guys racked up 1,000's of miles as I did. I put 4,000 miles on my 4.80x8 tires and never had an issue. It's about the weight on trailer tires. If you running empty or light loads (600lbs say) then I see no problem. Just grab a spare incase you get a flat. FWIW I never had a spare. Just a can of fix a flat. I ran 55-75mph all day long. I also ran my psi at 22lbs not the 60 psi on the sidewall. We ran lower psi's because at max psi the little trailers would bounce over it's own shadow. Tires were Cheng Sinh B rated. Max 590lbs at 60 psi. Think about it for a minute. If you took a tire and rim and just rolled it down the road at 70 mph, then took the same tire mounted to a trailer that had the max load on it, which tire would be under the most stress? Those tires aren't going to fly apart unless they're being stressed. Here's a pic of my setup.

CapriRacer wrote:
First, 4.80-12 tires are restricted to 65 mph.

Second, 4.80-12 tires come in different load ranges: Load Range B - 785# at 60 psi, and LR C - 990# at 90 psi.

I'm going to guess the OP has LR B - and if that is so, then towing with 1500# is really marginal on load carrying capacity.

Also, there is a less than well known provision in the tire load tables that if you want to boost the max speed of trailer tires from 65 mph to 75 mph, add 10 psi. If you want to get to 85nph, also reduce the max load by 10%.

So the OP's original question? Like others, I would be more concerned about the tires than the bearings.

Agreed!. I am learning that the bearings won't be the issue. I can handle that with good synthetic grease and Timkins, however the tires will melt going 1500 miles one way with stops of course, then return trip. I think I will switch to passenger tires. The trailer is small, and the loads small as well, but the speed can safely be increased being a passenger tire. The load per tire will be rated around 900lbs which then will make it 1800 lbs. That trailer would never hold that weight so I am safe.

First, 4.80-12 tires are restricted to 65 mph.

Second, 4.80-12 tires come in different load ranges: Load Range B - 785# at 60 psi, and LR C - 990# at 90 psi.

I'm going to guess the OP has LR B - and if that is so, then towing with 1500# is really marginal on load carrying capacity.

Also, there is a less than well known provision in the tire load tables that if you want to boost the max speed of trailer tires from 65 mph to 75 mph, add 10 psi. If you want to get to 85nph, also reduce the max load by 10%.

So the OP's original question? Like others, I would be more concerned about the tires than the bearings.

gmw photos wrote:

SweetLou wrote:

gmw photos wrote:
I've got a little three rail motorcycle trailer that I bought new in 1972. Came with 4.80x8's, at some time along the line I put 5.60x8's on it. We towed that thing way too fast for many years, and never failed a bearing. I always kept them greased of course.
I did destroy a few tires though ! Every one of those tires that failed, did so at highway speeds, and every one of the was totally destroyed by the time I got pulled to the side of the road and stopped.

I tow with a Dodge Cummins dually. This little trailer is a speck to it for towing. I want to run 68-70 mph so I guess I need to buy a spare tire.

If there is any way you can do it, given the four hole hub and whatever clearance issues, I would put the largest diameter radial tire you can possibly fit.
I'll no doubt start a firestorm here, but I would MUCH rather have some sort of 13" car tire on there than ANY st tire.

These rims are 12inch and a 5 lug pattern not 4. I can put passenger tires on this trailer which would be 155 x 80R12. They would be rated at 108mph hwy speed which sounds better to me. Those little tires will be burned off in no time. Bearings may be an issue, however most people's experiences don't dictate that.

gmw photos wrote:

SweetLou wrote:

gmw photos wrote:
I've got a little three rail motorcycle trailer that I bought new in 1972. Came with 4.80x8's, at some time along the line I put 5.60x8's on it. We towed that thing way too fast for many years, and never failed a bearing. I always kept them greased of course.
I did destroy a few tires though ! Every one of those tires that failed, did so at highway speeds, and every one of the was totally destroyed by the time I got pulled to the side of the road and stopped.

I tow with a Dodge Cummins dually. This little trailer is a speck to it for towing. I want to run 68-70 mph so I guess I need to buy a spare tire.

If there is any way you can do it, given the four hole hub and whatever clearance issues, I would put the largest diameter radial tire you can possibly fit.
I'll no doubt start a firestorm here, but I would MUCH rather have some sort of 13" car tire on there than ANY st tire.

The bolt pattern is typically 4x4" or 4x100mm which does allow for automotive tires and rims and long as you relocate the fenders with taller brackets.

I also had a little trailer with 8" rims that never failed me, but I stored it covered or inside, repacked the bearings annually and kept the speed bellow 60 mph. After 10 years I did replace the valve stems, but the tires and bearings were original when I sold it after 14 years of use and two cross country trips.

I used Bearing Buddies and would find with the 12" tires that the bearings would need a lot of grease after a 400 mile trip. Started taking a grease gun along for the ride so I could add grease at my destination before making the return trip.

I look at it in terms of what happens if a bearing fails and a trailer loses one of two tires. I was in a car towing a trailer filled with firewood when that happened and within seconds that wood was all across the highway. Luckily the oncoming cars were able to stop in time or it would have been very ugly.
The trailer tongue as badly twisted and needed to be cut off with a torch and replaced. Now I take a conservative approach and use trailers with full size tires and I keep the bearings well greased.

SweetLou wrote:

gmw photos wrote:
I've got a little three rail motorcycle trailer that I bought new in 1972. Came with 4.80x8's, at some time along the line I put 5.60x8's on it. We towed that thing way too fast for many years, and never failed a bearing. I always kept them greased of course.
I did destroy a few tires though ! Every one of those tires that failed, did so at highway speeds, and every one of the was totally destroyed by the time I got pulled to the side of the road and stopped.

I tow with a Dodge Cummins dually. This little trailer is a speck to it for towing. I want to run 68-70 mph so I guess I need to buy a spare tire.

If there is any way you can do it, given the four hole hub and whatever clearance issues, I would put the largest diameter radial tire you can possibly fit.
I'll no doubt start a firestorm here, but I would MUCH rather have some sort of 13" car tire on there than ANY st tire.

gmw photos wrote:
I've got a little three rail motorcycle trailer that I bought new in 1972. Came with 4.80x8's, at some time along the line I put 5.60x8's on it. We towed that thing way too fast for many years, and never failed a bearing. I always kept them greased of course.
I did destroy a few tires though ! Every one of those tires that failed, did so at highway speeds, and every one of the was totally destroyed by the time I got pulled to the side of the road and stopped.

I tow with a Dodge Cummins dually. This little trailer is a speck to it for towing. I want to run 68-70 mph so I guess I need to buy a spare tire.

I've got a little three rail motorcycle trailer that I bought new in 1972. Came with 4.80x8's, at some time along the line I put 5.60x8's on it. We towed that thing way too fast for many years, and never failed a bearing. I always kept them greased of course.
I did destroy a few tires though ! Every one of those tires that failed, did so at highway speeds, and every one of the was totally destroyed by the time I got pulled to the side of the road and stopped.

One item to consider in this situation: I upgraded my utility trailer to 5.30 x 12 tires to buy some extra load margin. This size should fit the same wheels as a 4.80 x 12 tire. I've got thousands miles, mostly long trips on the highway, with widely varying loads on these tires - and no problems.

In my experience, bearings aren't a problem, even for the low-end utility trailer kits. My bearings are still original from 1992 - but get re-greased regularly.

5.30 x 12 tires are a fairly cheap and easy upgrade that makes the typical low-end utility trailer kit much more capable for long trips.