Spare ST Radial Tires - Storage and Replacement

[cricketkj26]

I run four ST 225R15 Radial 10 ply, load E tires (2830Lb) on my 20ft  enclosed Pace American Pursuit 7000Lb GVWR.  I carry 2 spares - 1 is a 

1 year old  Goodyear Endurance same as the four on trailer. It is stored in recessed tire well in the deck of the trailer.  The other spare is the 

same size and rating but is a Power King Towmaster.   It has never been used and stored inside the trailer in north FL for 7 years.

How long can these tires be a viable spare if never used and kept inside the trailer out of the sun ?   Trailer gets used approx 3000 miles a 

year right now . All tires including spares are balanced. Should the spares be kept in the garage and deflated when trailer is not being used ?

Thanks, Cricket

 

 

[3macboys]

Far from a tire expert but I'll pass along what I learned from fleet seminars and tire company reps.  Trailer tires are a special case due to their lack of use for extended periods of time.  It is not the total mileage on the tires but frequency of use as the tires need to rotate and generate some heat to keep the tire compound from breaking down.  If I recall correctly it's not so much sunlight as ozone and exhaust fumes that can be very damaging to the tires.   The problem with tires is that the ones with cracked sidewalls are easy to see, the ones with internal problems you won't know about until it's too late.  For peace of mind I'd be replacing the 7 year old one.  Other opinions will vary...

[Robert Street]

I have experienced the horrors of the question  I believe it was the Ocala National show early 2020 I believe.  Probably late February or March.  

I carried at that time 3 spares in addition to the 4 on the ground.  For that trip the four on the ground were at the beginning of their 5th year and I thought since it was "winter" heat wouldn't be a problem and could change them when back from that show, as I have had several trailer and tow truck tire issues before.  The tires on the trailer were Marathon's and the spares were two Carlisle and one tow master  I dont remember the date of the carlisles but the tow master was 7 years and was only used about 500 or so miles.  I use a tire monitoring system but it wasn't any help on this particular show.  I also carefully keep the tires to correct inflation.  I'll admit this was prior to realizing there is a max speed on trailer tires.  Since, I am a reformed tower.

I busted 3 tires that were on the trailer and had to stop and buy some tires in NC as was getting low on spares.  anyway on the way back I had one original 4 year old marathon on the ground and the one 7 year old barely used Towmaster.  well did ok until in NC on the way back on I-95 and blew out the last marathon and put my last spare on.  That tire lasted probably 100 miles before it blew and this one exploded with such force it tore up 4 panels of my trailer, the fender and damaged the tire wheel well but didn't penetrate into the trailer.

So.  I would never consider using your 7 year old tire.

My tire dealer told me that cracks on the exterior don't always appear on trailer tires but there is a way to determine if they might be ready to blow.  The tread will slightly crown up in the middle of the tire or a "golf ball" will appear on the sidewall.  And I am a reformed towing person now limiting towing speeds to 70 MPH.  The new Endurance series of tires are the latest design and the max speed is about 80 I think.  Never popped one of them though.

Robert

[Ed Nieves]

I have been using Maxxis tire for a long time and never had issue with them. I have driven on 4 year-old maxxis on 3000 mile ( loaded) trips and they've held up nicely. 

 

 

[Trulyvintage]

The Goodyear spare you mentioned

should be rotated into use as you

use your trailer.

 

The other is not not suitable 

to be used as a spare tire for

the same reason it is not 

on your trailer now.

 

You are better off to purchase

another new ST tire for 

the second spare and plan

on rotating into service as well.

 

 

Jim

Edited February 27, 2023 by Trulyvintage (see edit history)

[cricketkj26]

Thanks all for your comments, experiences, and advice.  Cricket.