When do you replace a spare?

[Supernaut]

I had a 2012 vintage BFG KO that has lived a hard life under my truck since I bought it in the fall of 2013. I had a good look at it the other day and it was showing cracks between the tread blocks.

I run solo sometimes, most often in the desert. The tire did not inspire confidence and I wasn’t ready to trust it. I had it replaced with a new KO2 to match what I’m running now and plan to put that tire in the rotation.

Was I hasty through? BFG says replace a spare at 10 years. The way the original KOs would throw off chunks of tread and the signs of dry rot made me feel like 7 years was enough.

Still, I might have acted too quickly. Advice and perspective appreciated.

Didn’t find this had come up when I searched. Apologies if there’s something I’ve missed.

 

[Specter]

I have always rotated my full size spare into the fold when I rotate my tires. It keeps any one tire from getting to beat up, dry rotting, etc. while underneath or on the back, and reduces the amount of time before I need new tires by 20%, (at which time I get five new ones). The best part is I always have confidence in my spare. Just a thought.

 

[MidOH]

I do the same as you did. My spare is only a spare. Never rotated in with the prime tires.

I'll use cheaper, harder, work truck tires for spares. If I need a spare MT, so be it, but not right now. If I need a matching spare MT, then it goes in the bed as a 6th tire, two spares in a ways. My point is, if my spare absolutely needs to match my MT's to safely get off the trail, then one spare isn't enough anyways.

I drop my spare once a year to lube the mechanism, and to Simple Green the tire to prevent dry rot. Ford Superduties will only fit up to a 35'' spare.

 

[KonzaLander]

I have always rotated my full size spare into the fold when I rotate my tires. It keeps any one tire from getting to beat up, dry rotting, etc. while underneath or on the back, and reduces the amount of time before I need new tires by 20%, (at which time I get five new ones). The best part is I always have confidence in my spare. Just a thought.

I follow the same practice.

@Supernaut I think you made the right choice by replacing the cracking spare.

 

[Supernaut]

Thanks for the replies. Made me feel a little better about spending the money for the replacement.

 

[Specter]

Thanks for the replies. Made me feel a little better about spending the money for the replacement.

It why we are all here! Cheers.

 

[Charles M]

I have always rotated my full size spare into the fold when I rotate my tires. It keeps any one tire from getting to beat up, dry rotting, etc. while underneath or on the back, and reduces the amount of time before I need new tires by 20%, (at which time I get five new ones). The best part is I always have confidence in my spare. Just a thought.

I get 5 at a time too. I like how they match up and work more equally together. I also like the ability to replace one of them if I destroy one and just work it into the rotation. If when I have to replace a bad tire is close to a time to replace all the tires then I may only need to get four new ones to go along with the replacement.

My tires last longer between needing new ones too. With aftermarket rims and a spare mounted on the back I like the look of them all being the same too.

 

[Buckaroo]

I'd have replaced that spare too.
I don't like the thought of having a dubious item on my van and having to rely on it in the middle of nowhere.
good choice.

 

[bgenlvtex]

Pretty well accepted in the tire industry that the failure rate increases exponentially at about 5 years.

When a tire is built, bonds are created (forced) between dissimilar materials. Those bonds begin to degrade at the moment they are created, and will continue to do so for life.

There are too many variables to say that you need to pull tires at X, but just be conscious of what is going on with the and plan ahead.

I put lots of miles on my vehicles, I buy sets of 4 generally and move the best tire from the ground to the spare position. The only vehicle I have had in recent history that this is not the case for was a 2017 JKRHR that had 5 matching wheels and TPMS.

 

[64Trvlr]

If you have a posi, locker or other traction aid in your differential make sure your spare is the same size as the rest of the tires. Close doesn't count here as the different sizes are also different tire speeds. The differential will try hard to correct the tire speed on the tire spinning faster to the one that it thinks has traction.

 

[oldmopars]

Something else to keep in mind with all of this is exposure. UV kills tires and causes them to dry rot faster than a tire sheltered from the UV rays. That is why RV owners cover the tires to keep them from the UV rays.
So, if you keep a tire under the truck or inside like on my Suburban, they will last longer than a tire that is hanging off the back off the rig all the time. If yours is hanging off the back, check it, you will see over time the top that is exposed will start to dry rot and crack before the bottom that is in the shade. I suggest running a cover for exposed tires. It does not look as "Cool" but will save the tire.

Also, most tire makers say that 7 years is the life cycle of a tire. If its not worn out by then, replace it due to breakdown as mentioned above. One tire brand has a slogan "there is a lot riding on your tires" and it is true. Tires and brakes are the most important parts of your vehicle and the leading causes of non-human caused crashes.

 

[MOAK]

Lots of good posts here, so here is the method to my madness. I run 7 tires on 7 wheels, all interchangeable. 5 on the Cruiser and 2 on the trailer. My truck automatically gets 4 new tires every 40,000 miles. The youngest 3 tires stay for the trailer and a spare. The oldest 4 I sell. I’ve been completely honest with any prospective buyer and still, they don’t even flinch at $75- 80 per tire.. All said and done I’m getting a set of 4 BFG or Generals for 4 to 500 dollars. Rule # 1? Never ever skimp on tires.. once I learned this some 30 + years ago I’ve never had a flat and I get good bucks for used tires.

 

[Michael]

Thanks for the replies. Made me feel a little better about spending the money for the replacement.

Ya - I noted a split in my tire and opted to drive home 600 miles. The tire disintegrated 1 mile from home. Good call replacing. :)

 

[Billiebob]

Thanks for the replies. Made me feel a little better about spending the money for the replacement.

Look at it like an amortization. The old tire, $120 over 6 years, $20 a year. The new tire, $200 over 10 years, $20 a year.

Pretty cheap insurance.

 

[Mojavewanderer]

I have a trailer made from a 1974 Datsun pickup truck, and it still has the original spare tire under it. Looks like it has never been used. Definitely not road worthy, but neat that it’s still there. My truck is a 1980 model year, and it had the original unused spare under it too, but I replaced it. When I get new tires, I save the best old one for a spare.