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Pick · 05-02-2003, 09:52 AM

Here is a snip from a thread over at rv.net:

Quote:

Not to try and shoot you down, but studies done on OTR truck trailer combos's, show that if a trailer has too deep a tread, then this will cause trailer sway. This is more than likely why a ST tire does not have as much tread depth as an equal LT tire. On bigger tires, 19.5+" tires, you can find trailer tires and steer tires with the same tread, core build etc, but one will have over an inch of tread, for the truck, but the trailer version will have about 1/2-3/4" of tread, and the sales brocure will say for less sway on the trailer.

Maybe this is why I have sway after my axle replacement? I did replace the tires and they are bias ply LT's. I don't think the tire dealer could find ST's. Maybe they do not make ST bias anymore. Anyone know for sure?

**Action** · 05-02-2003, 10:38 AM

Pick,

My guess is your bullet does not have a 80,000 pound load. So the tires and tread are going to be a shade different than a commercial trailer. Another reason that I have been told that ST (or trailer tires) are of shorter tread is that most of the time the tires are sitting - parked. In fact most of the time the tires will crack and rot long before the tread is worn down.

For your situation, look and tread width and tire construction of these tires vs your old ones.

As to suggested solutions..... vary tire pressures by 3 psi. Make sure tire pressure is the same from side to sie. Look at your shocks, worn or loose. In fact is there anything loose... axles, wheel bearings, coupling. Are the axles mounted in the exact same location as the old ones. An inch makes a hugh difference. Distance from coupler to the center of the axles is the critical distance. Tire construction (even in same size and type) can make a difference. -- Example: I went from a Fisk radial tire to a Michelin radial tire of the same size on my truck. Big difference in handling.

And ST bias ply tires are available. Discount tire locally can order them. But why, other that being original.

>>>>>>>>>>>>>>>>Action

davidz71 · 05-02-2003, 11:24 AM

It was my understanding that the sidewalls are built sturdier on ST tires so that they will take the abuse when turning sharp corners or maneuvering while parking the trailer, especially a dual axle trailer. They also have built-in chemicals which retard UV ray damage. I've watched the tires flex and scuff the pavement while someone backed my trailer into a tough spot and it made me wonder how much mileage I will get out of them. So far I have approximately 3,000 miles on them and the tread looks fine.

Pick · 05-02-2003, 12:46 PM

Action,

Yes, I have checked all of the "usual suspects". Axles are mounted dead on where the other ones were, within 1/16th of an inch. Bearings repacked, and no wobble. Shocks have been replaced. One thing, I am going to try on the next trip is this, the old tires were load range C, and inflated to their 45 psi max. The new tires are load range D, and I had not inflated them to the max of 60 psi. Could this make a difference also? They do have a real DEEP tread, though, that is what makes me think this could be causing some of the sway. I wonder how many miles a set of these tires would last on the coach if it was used quite frequently. Anyone ever WEAR a set out on their coach?

**Action** · 05-02-2003, 01:00 PM

To what pressure are the new tires inflated?

I have had 3 boat trailer since 1986. (In addition, to my bullet that I have only had for a year) A 19', 27' and my current 26' boat trailer. I have never replaced tires due to tread wear.

>>>>>>>>>Action

femuse · 05-02-2003, 02:07 PM

Quote:

. Anyone ever WEAR a set out on their coach ?

Yes and no.

What happened with us is, over time, we had to replace them one at a time: one got a bad cut, another a puncture in sidewall,.....

Our 1974 has maybe 60,000 miles with us. We started with a new set, we now have them all replaced, one or 2 at a time: they didn't "wear" out evenly at all.

53flyingcloud · 05-03-2003, 08:29 AM

Action

Quote:

To what pressure are the new tires inflated?

I would think you'd be safe to use the max pressure listed on the sidewall of the tire.
On mine, it's 65lbs cold. (if that's any help to you)
ciao

**Action** · 05-03-2003, 09:32 PM

53Flying Cloud,

Yes I believe Pick's issue is tire inflation. (or not enough) I would also, suggest using the max inflation from the side wall. Then if the desired result is not obtained reduce the presure by 2 psi on front tire.

I am still curious as to what pressure Pick was running.

>>>>>>>>Action

Boondocker · 12-02-2006, 12:17 PM

Well, since the last post in this thread was 3 years ago I dont feel to bad....
Anyway, I was towing the other day into a cold front and had the impression that as the air temp dropped, I was getting increased sway from passing trucks. Is this because the airpressure in the tires was less? Or is it more likely something else?

Inland RV Center, In · 12-02-2006, 12:58 PM

Quote:

Originally Posted by Gen Disarray

Well, since the last post in this thread was 3 years ago I dont feel to bad....
Anyway, I was towing the other day into a cold front and had the impression that as the air temp dropped, I was getting increased sway from passing trucks. Is this because the airpressure in the tires was less? Or is it more likely something else?

Probably gusty winds associated with a weather frontal system.

Andy

2airishuman · 12-02-2006, 01:08 PM

cold air is dense...more push

hitch is metal which shrinks when cold...loosey goosey steering too

tires warm up rolling...pressure goes up to

cold dead threads not good... rewarmed as zombies

neurotransmitters different cold...perhaps you imagined it all

2air'

Boondocker · 12-02-2006, 01:25 PM

I guess the cold air being more dense would make for more force. I didnt feel like it was that gusty out. I can tell you I didnt like the loss of stability. I guess the moral of the story is, winter towing will be slower even under dry conditions.

**azflycaster** · 12-02-2006, 08:35 PM

Your tires will drop 1 PSI forevery 10 degrees F. They will also drop 1/2 PSI for every 1000 feet of altitude you go down. That means if you air your tires to 50 PSI on a warm afternoon (70 degrees)at 4000 feet. You drive down the hill and the next morning it's 30 degrees at sea level, your tires will have around 44 PSI. I would guess from what you stated that your tires were a little low and that was a factor.

flynmike · 12-03-2006, 04:29 PM

Quote:

Originally Posted by 2airishuman

cold air is dense...more push

hitch is metal which shrinks when cold...loosey goosey steering too

tires warm up rolling...pressure goes up to

cold dead threads not good... rewarmed as zombies

neurotransmitters different cold...perhaps you imagined it all

2air'

I'll have what he's smokin'

Mike