Trailer tire size range

justsomeguy · Sep 9, 2012

If the tire is an inch shorter in diameter, that should translate to a half-inch lowering of the axle, yes? Or am I misunderstanding the way tires are measured?
My tires are 215-75-R14, and my driveway can be hell sometimes, but I haven't noticed any dragging of the V.
As low as the V is on our trailers, a half-inch should be negligible. Still, I try not to center-straddle protrusions in the roadway!

justsomeguy · Sep 9, 2012

Caveat- I could be mistaken as to how tire height is measured!

http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=46

Model 70 · Sep 9, 2012

Correct, one inch smaller diameter lowers the trailer 1/2 inch.

justsomeguy · Sep 9, 2012

Model 70 said:
Correct, one inch smaller diameter lowers the trailer 1/2 inch.

I'm still not sure.

jjsbiggs · Sep 9, 2012

etrailer

I found that etrailer.com had the best prices and will ship for free for orders over $150.

Timo42 · Sep 9, 2012

Might want to look into galvanized rims, they will last longer. Make sure the tires can handle the load and are ST rated trailer tires. At that price you are looking at noname chinese tires, if you are hauling any distance, I would spend the extra money for Marathons.

monkeybars · Sep 10, 2012

225 has nothing to do with tire height or diameter, it is the width of tire in MM, tire hieght or aspect ratio will be a number in % such as 70 or 75, which means tire hieght (tread to bead) is 75% of 225 plus rim diameter.

tkanzler · Sep 10, 2012

I'd be more concerned about the tires' load capacity. That boat is something like 2200 lb or so, plus whatever has been added, plus maybe the outboard (inside, or on the mount), plus the trailer. You're probably over 3000 lb, so you'd want tires with a load rating of 1500 lb or more. ST205/75D14 load range C, which are rated 1760 lb at 50 psi, are what's on mine, but I don't know what diameter yours was designed for.

Just putting it out there.

tkanzler · Sep 10, 2012

Well, here's a page full of 15" radial Special Trailer (ST) tires, mounted, including galvanized (as well as alloy) wheels. I sorted on 5 on 4-1/2" bolt pattern (probably the most common on boat trailers), but you can sniff around to see what's out there as standard fare.

This is far from the only place to get mounted tires, of course - I'm just posting it so you can see the range of what's available. Back up to Tires and Wheels to eliminate the filters so it shows everything.

http://www.etrailer.com/dept-pg-Tires_and_Wheels-pt-Radial_Tire-sz-5_on_4~1|2_Inch-pc-15_Inch.aspx

Timo42 · Sep 11, 2012

ST tires are designed for trailer use, they have stiffer sidewalls, LT tires are designed for trucks. Just because it's the same size doesn't mean they are interchangeable. We have been over this before.

seaStan · Sep 11, 2012

Like others have said, load range or capacity is more important than i/2 inch in height. I have found that tires with a small difference in size can have different load ratings and I always go for the higher load range. I have blown a tire while towing and had one come off while towing(always check your lug nuts before towing) so I am careful with my tires. Northern Tool was a lot of trailer tires with some good sales and coupons online. My last set of 15 inch tires and rims were $88.00 each, a great deal if you can wait for a good sale.
When my tire came off(hitting 2 other cars) I think someone was trying to steal them. Lug nuts were missing on the other side that didn't come off and they were new tires. I was on the way home from a day at the lake and it was not the first time someone has messed with my trailer while I was on the water so now I check my trailer before leaving.

tkanzler · Sep 11, 2012

crosswind said:
Problem is, finding a galvanized rim at the width of standard tires to fit the 5 on 4 1/2 lug pattern

Unless you already have the tires, why not just order them online, already mounted on galvanized wheels? At etrailer.com, shipping is free over some amount, but a pair of mounted tires is more than that. I've bought 4 of them so far, and they've showed up a few days later, already inflated (had to drop the pressure a little, in fact).

No connection, just a happy customer.

monkeybars · Sep 18, 2012

hard to beleive they would attempt to steal cheap chinese tires, but if you do use high quality chinese tires like goodyears or a quality LT truck tire I wouldn't skimp, as long as i was shelling out 180 bucks for a tire rim combo i would spend the extra 20 dollars for a quality set of wheel locks for sure.

anchorclanker · Sep 18, 2012

Lug nuts loosen themselves. Cars, trailers, trucks, they all can have lugs come loose and do so quite often. Some manufacturers have tried to counter it by using left hand thread (backhand thread) on the left side (road side). Most trailers have a sticker advising to check lugs every 500 miles. Its much more likely the lugs self loosened and the wheel came off on its own rather than anyone trying to steal them.

Main differences between auto and trailer tires is that trailer tires have different compounds to limit oxidation in sunlight. Because trailers usually sit outside the sun will usually destroy them long before anyone will wear them out. They are also generally bias ply, thats where the heavier sidewall comes in.

I have ran radial tires on trailers a lot. You really just need to learn how to read tire side walls and know what kind of weights you'll be placing on them. Personally, I would rather have a radial shred itself without damaging everything around it, than watch a bias ply get cocked on the rim and try to rip the axle out or take the fender off.

Lots of debate on new vs used tires, and age. I was given a tour of a Bandag retread plant as well as explaining tire casing inspection by a guy a knew. I learned how to inspect tires visually and what to look for. Condition is the critical factor in a tires viability more than age, followed by application and maintenance. The Ford Explorer/Firestone tire debacle would never have occured, had Ford not reduced recommended tire pressures below anything than made common sense. Point being that you can destroy a good tire rapidly by running it under inflated and overloaded on a hot day.

Myself, I almost never buy new tire's. Plenty of good used ones around that have already proven themselves. Before you argue how great a new tire is, know that no Indy or F1 car, or NASCAR car, ever starts or runs on new tires. New tires are too unpredictable, so they run them on test tracks a bunch of laps to prove them first. Some truckers and Bus companies wont run virgin tires on the steer axle either, for the same reason.

tkanzler · Sep 18, 2012

I wonder if they make lug nut indicators for 1/2" wheel studs?