12 inch wheels/tires

[mikere]

I have a small 13' TT with a dry weight of 850 lbs. On a recent trip I had some bearings burn out and the mechanic doing the replacement work commented that he was surprised that I'd made it 2500 miles on bias ply tires (6 ply equivalent). I thought this odd as the tires are rated for 1045 lbs. each (two tires) and 65 mph at 80psi. Was this guy blowing smoke or does he have a point? I'm thinking about replacing the old hubs on this trailer before a trip to Mexico in a few months (from Vancouver Island) and figured with the potential difficulty in acquiring tires in Mexico I might want to do as much research and preparation as possible before I leave. Fortunately the old bearings didn't leave me on the side of the road, but did overheat and spit grease as I rolled into a town and checked things over.

Any thoughts on this topic? Also any experience with the bearings and hubs available from eTrailer? Is it possible (advisable?) to put 14" tires on the 4.5"x 5 hubs I have? Thanks for any advice you may have.

[mikere]

Here's a fun fact. I just looked around for narrower 14" tires and came across a p155/55R14. It's listed diameter is 21", which is LESS than 5.30-12, which is 21.9".

https://simpletire.com/federal-p155-55r14-a55i4afa-tires

https://www.etrailer.com/question-77837.html

At least as far as the bearings are concerned, there's not any reason to change.

[gmw_photos]

If it were mine I would do whatever it takes to up the size to a 14" or 15". On a trailer that light, I'd be happy with a P metric radial. If going 14" though, a possible choice in a LT is Hankook RA18.

With that choice, I could pull any speed, and the tires would easily last out for 7 to 10 years, even if the trailer were to run upwards toward 100K miles.

[mikere]

Lynnmor wrote:

Don't see where you allowed for suspension movement.

The 0.2" is between the sidewall of the tire and the outside of the wheel well - not much lateral movement in any kind of suspension unless something's broken. But still, not really enough room in any case was my point.

[Lynnmor]

mikere wrote:

I did some measuring today of clearances around the current tires and it looks like the outer wheel well is the limiting factor with about an inch to spare with the current tires. About two inches to the inner wheel well and about an two inches of clearance above the tire. Not much to work with. I'm trying to figure out if p175R80/15" will work, but I think they might reduce the critical gap to about 0.2", which isn't much.

Don't see where you allowed for suspension movement.

[mikere]

spoon059 wrote:
12" rims? At 65 mph those things are moving, probably going 1200 RPMs. A standard 15" rim with tires is probably closer to 800 RPM. I would put the biggest wheel/tire combo that would fit under the fender if it was my trailer and I was intending to go that fast/far.

The 5.30-12" are 21.9" diameter. It comes out to just over 955 rpm. Probably a big part of why they have a maximum rated speed of 65mph. I've checked the timer temperature by touch after many stops and they've never been more than a bit warm feeling, so likely not much over 100 degrees.

I did some measuring today of clearances around the current tires and it looks like the outer wheel well is the limiting factor with about an inch to spare with the current tires. About two inches to the inner wheel well and about an two inches of clearance above the tire. Not much to work with. I'm trying to figure out if p175R80/15" will work, but I think they might reduce the critical gap to about 0.2", which isn't much.

[JIMNLIN]

op wrote:
Was this guy blowing smoke or does he have a point?

He was correct.
Bias ply tires run hot...hotter than a radial especially those tiny 12" tires and especially at highway speeds.
Years back 12" tires were common on small trailers ...rv and non rv and were very problematic.
One of the first mods I did to any trailer (rv and non rv) with a bias ply tire was dump them and go with a 13" or 14" wheels and P radial tires. That move eliminated bias ply blues issues as we called them back then.

etrailer can help you with axle/hub upgrades. Give them a 1-800 and tell them what you want and what you have. Those folks have been around for a long time and are well up on those type mods.

[Lynnmor]

midnightsadie wrote:
X2 ,those tires are really spinning,, timken bearings and good high temp grease. I carry two spares and a complete hub assembly.when installing the lock nut don,t tighten it real tight, read how this is done and watch a couple googles on it.

Good that you carry spares.

That is not a lock nut and you don't tighten it at all, you should have a very small amount of clearance. Some of the videos online were done by folks that shouldn't work on a wheelbarrow, so be careful using those. Dexter Instructions

[spoon059]

12" rims? At 65 mph those things are moving, probably going 1200 RPMs. A standard 15" rim with tires is probably closer to 800 RPM. I would put the biggest wheel/tire combo that would fit under the fender if it was my trailer and I was intending to go that fast/far.

[Lwiddis]

Your TT’s dry weight is useless. However, your TT’s color is important. Those tires are rated for 80 psi?

[midnightsadie]

X2 ,those tires are really spinning,, timken bearings and good high temp grease. I carry two spares and a complete hub assembly.when installing the lock nut don,t tighten it real tight, read how this is done and watch a couple googles on it.

[Lynnmor]

eTrailer sells junk bearings, perhaps some are OK, but I would use NOTHING but Timken after failures of their cheap, Chinese bearings. One source: here.

Use a good quality grease that is specifically made for wheel bearings, not a general purpose grease. Bearing Buddies aren't needed.

[mikere]

theoldwizard1 wrote:
Blowing smoke ! Nothing wrong with good quality tires as long as you are not exceeding the load capacity and are keeping them properly inflated.

The smaller the wheel and tire, the faster it spins. The faster it spins, the more important good lubrication is. Every time you fuel up, check the temp of the bearing/hub. If you are spitting lube or you can not put your hand on it for more than a second, it is time to re-lube/replace the bearing.

An extra 2 sets of bearings are cheap insurance. Tools/grease to do the job are cheap insurance. A second (even unmounted) spare is also cheap insurance.

eTrailer does not sell "junk". Call them.

Thanks for your reply, sir. I had been mostly following your advice, especially on the return trip with the new bearings. The hub temperature was never more than slightly warm to the touch, but I might have pushed the limits a bit on the stretch before the bearings went - we were going from Edmonton to Fairview Alberta and we pushed the speed a bit more than the rest of the trip - probably a long stretch of 70mph did them in. From now on, we'll check this every single stop. I'll certainly be bringing 2+ sets of spare bearings, possibly including fully set up and grease packed hubs as we have a lot of storage we haven't been using. I don't want to get gouged again on part costs. The place we had the work done had a reasonable shop rate, but charged 150+ (CDN) for the four L44643 bearings and another 50+ for two seals.

Very good to know about the tires. I can get 145-12" radials that will almost drop in fit for the 5.30-12" that are on it - and keep the speed down below 65mph for sure. What are your thoughts on Bearing Buddies in this kind of set up?

[theoldwizard1]

Blowing smoke ! Nothing wrong with good quality tires as long as you are not exceeding the load capacity and are keeping them properly inflated.

The smaller the wheel and tire, the faster it spins. The faster it spins, the more important good lubrication is. Every time you fuel up, check the temp of the bearing/hub. If you are spitting lube or you can not put your hand on it for more than a second, it is time to re-lube/replace the bearing.

An extra 2 sets of bearings are cheap insurance. Tools/grease to do the job are cheap insurance. A second (even unmounted) spare is also cheap insurance.

eTrailer does not sell "junk". Call them.