12" trailer tires: Pros and Cons

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#1
I recently built a 5x10 utility trailer w/15" wheels. It is great, but it is also very heavy for my Camry and Tacoma 4cyls. I have a set of 12"wheels/tires/springs and a axle that I am thinking about using to build a lighter trailer with. I also put on Buddy Bearing dust caps on the 12s when I was using it a lot. Everybody says that 12" tires suck, but I used it for a year before and didn't really notice anything different than my 15" tires on my new trailer. What gives? What is so bad about 12" tires besides the rinky dink appearance?
 

WaltCMoto

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#2
If you repack the bearings once a year, you will be fine. They spin faster and therefore put more wear and tear on the bearings. Ive put on many miles on my small tires with no problems.
 
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#3
I don't know of any pro's - just con's. Bearing/Tire fatigue is very high if you trailer alot. The bearings are being used considerably more and the tires are typically not well bulit in comparison to the 15". I would stick to the 15"!!
 
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#4
A guy was telling me that 12's, when being pulled, actually create a dragging action b/c the wheels are at a higher RPM than the 15's. I understand what he is implying, but I towed those 12's at 80MPH for probably around 6 or 7 thousand miles in the course of a year or two and never notice that phenomenon. Any input?
 
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#5
I was worried about buring up the bearings also.
My fears were unwarranted.
They have held up just fine.
Last year i had no problems towing my 12" equipped 4'X8' from Farmington,NM to Stillwater,OK for DW02.
I didnt take it too far over 75 mph though (just in case).
I did hit 85 or so though but not for extended periods.

Wish i could have tested those bearings again this year........ :( :whiner:
 

gixer

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#6
I have been running 12" for a long time with no ille effects. I was even doing 85 mph for a long time and it was fine. I have bearing buddys on the bearings and they keep them packed with greas really well. Just pump some greas in there every once in a blue moon and you are set to go. Mu buddy uses 8" tires and he ahs been fine also. He carrys around 2 Harlys on his and you know that weights more than a couple of dirt bikes.
 
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#7
Somebody check my math, but here is what I get for bearing RPM for 8,12 and 15" tires at normal speeds.

MPH 8" 12" 15"
30 1261 840 672
40 1681 1120 896
50 2101 1401 1120
60 2521 1681 1345
70 2941 1961 1569
80 3361 2241 1793

Wow, my 8 inchers are humming at 70mph.
 
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#8
Originally posted by kelseybrent
Somebody check my math, but here is what I get for bearing RPM for 8,12 and 15" tires at normal speeds.

MPH 8" 12" 15"
30 1261 840 672
40 1681 1120 896
50 2101 1401 1120
60 2521 1681 1345
70 2941 1961 1569
80 3361 2241 1793

Wow, my 8 inchers are humming at 70mph.
I'm within 2-3 revolution of your numbers, I used 3.145 for PI.
By the way not trying to brag but I got 12 inches... wheels on my trailer that is.
 

GAnderson

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#9
I have 15" wheels/tires on my light trailer and had 12" on a catamaran trailer - big difference in stability. When loading up gear on those 12" really had to watch weight. 12" should be fine on a 5x8 trailer - just keep weight/speed down and take care of spindle/bearings. Oh yeah, watch the leaf springs on those lightweight axle setups - broke 1 once.