Spare Tire

[pineranch]

I'm looking for advice. I have 614's on the wheels. I made a decision to keep the Marathon on the spare. My reasoning is;
If I need to put the spare on, it is to get me to the next town ONLY. We have Good Sam's also.
I didn't see the need to put a $300 tire in a rack to weather out.
Anyone check the tire size of most automobile spares?
Where am I going wrong in my thinking.
Mike

[tim43]

Yes, the fifth G614 was another $300 plus out of pocket, but my thought at the time and still is is that if one of the other tires should get punctured by a road hazard and repaired, it will become the spare and be replaced by the 614 carried as a spare. There is also a difference in tire size between the 614 in the marathon.

[HOOK]

Tim43x2

[Ozz]

I would get a same size cheaper tire maybe? I really don't know if the size difference would be any problem at all for the short need for it, but you know Murphy's law Mike.
I would plan on the worst happening and prepare for that; no tire available for 500 miles.. like that.

[1retired06]

I agree with you Mike. I got rid of the Marathons day of delivery for LTs, but kept the spare. Size difference is not a big deal for use as a spare, and I would not run any farther than necessary without a spare. Even our small home town of Littleton, population 800 has three places where tires can be purchased, or ordered/delivered the next day. Congrats on the 614s.

[tanner1070]

quote:Originally posted by 1retired06

I agree with you Mike. I got rid of the Marathons day of delivery for LTs, but kept the spare. Size difference is not a big deal for use as a spare, and I would not run any farther than necessary without a spare. Even our small home town of Littleton, population 800 has three places where tires can be purchased, or ordered/delivered the next day. Congrats on the 614s.

I did the same. Don't see any problem getting me down to road to get the good tire repaired and the Marathon back up the belly where it belongs.

[dieselguy]

Mike ... I fully agree with you. A spare is just that, a spare. Look at the spares in most vehicles nowdays ... the most minimum piece of rubber you can call a tire. There's a good chance your spare will never be wound down from it's carrier. I'll argue about saying five 614's already gives you another tire in case of puncture ... you'll still have to pay for two off and two on as the spare wheel is steel for those of us who have aluminum rims. It all boils down to peace of mind of the owner ... If I were to ever go with 614's, I'd save that extra $300 for spinners for my hub caps or maybe yet another LED yard ornament for my campsite setup

[bncinwv]

It still seems to me that the weak link in the smaller spare scenario is the axle. There is no differential, therefore the axle is going to turn at the same speed. The circumferential difference in the tires has to translate to axle strain (one tire has more rpm's per mile than the other when free-wheeling). Since the tires are not free-wheeling, the differential force has to be transferred to the axle to some extent based on the friction of tires and the road (Are these Chinese axles as well and subject to bending??). Maybe I am overthinking it since I am not an axle guru, nor did I stay at a Holiday Inn Express last night. Any rebuttals or agreement to my highly opinionated theory?? I take pride in the fact that I did not mention the words Marathon or Mara-bombs once in the composing of this post.......OOOPS!!
Bingo

[helmick]

Bingo
If the tires are not free-wheeling how can we back the Montanas into a tight spot. One side would be traveling more than the other side.

[bncinwv]

Good point Ron. I guess my thoughts are totally in left field, particularly when remembering that running different diameter tires are only not recommended for drive axles. So I was completely backwards when referencing the differentials, since it makes complete sense that different diameter tires would definitely not be recommended on axles that are driven by a differential. Guess this topic has had me totally brain-dead for the last couple of threads. On the bright side, I have now been educated and enlightened regarding this subject. At least I am getting brain exercise tonight!!
Bingo

[CORattler]

I kept my spare as well. I keep it aired up to 80psi. Should get me to the next town where I can get a replacement.

[BB_TX]

My spare is a Mission!
When I replaced the Missions on the ground with Michelins, I kept the Mission spare. And it still holds air fine. My thinking is the same as some others, the spare will only be no the ground long enough to get me to town for repair or replacement of the one that went flat.
Same reasoning for my trucks and cars. I have never bought a new tire for a spare for any of them. And there have been very few spares on any of those trucks and cars that ever hit the ground.
If I had a flat I would probably change it myself even though I have Coach-net.

[hunts800]

Had recent experience which directly applies. Had fairly new G614's, but had kept the Marathon spare. Picked up a large scissor blade which destroyed one of the G614's (went flat, no damage to trailer). Called Good Sam, dropped spare, only to find it is an 80R, not an 85R like the G614's. Good Sam guy would not install as it is a smaller tire, and they would not let me go on the road with one smaller tire for safety (liability) reasons. Upshot, had to purchase not only a new G614, but a new spare the same size as the G614's while on the road in Oregon. Would have been easier and cheaper to have put five G614's on at the time! Plus, finding G614's in a non-metropolitan area is difficult at best.

[pineranch]

I'm still confused. It sounds like if I stay out of Oregon, I can use my current spare and pump my own darn gas. I knew all those Californians moving to that state would screw it up also.
Mike

[dieselguy]

In reference to the Good Sam's experience.
Goodness, another reason I'm glad I live in the plains states. If it's round with just enough air in it ... they put it on. 80 - 85 is just aspect ratio or the width of the tire compared to the height. I think I would have asked for his 4 way tire wrench and proposed the guy go smoke his Lucky Strikes for about 5 minutes. Drag the spare from your car's trunk and stand it up next to your regular tire on the drive axle no less ...

[Art-n-Marge]

I think I agree with Bingo about the size of the tires being more important than not and having a spare not of the same size is a detriment. It's bad enough when the spare is gonna be slightly larger than the other tires because it has more rubber.

While the size of the tire does not matter when backing or turning a rig into a parking spot, this is typically done at very slow speeds. But driving highway speeds after correcting a flat is more critical that the tires be at the same size on the same axle. The single fixed axle with the smaller tire might tend to want to turn to that side or since the TV is just power dragging both tires in a forward direction, one of these tires is gonna be subjected to some unnatural dragging or forces and I think this is another mishap waiting to happen.

This is the major reason that a vehicle's cheater spare is limited to slower speeds and short distances for a vehicle and even in that case there is a differential to help combat the different sizes temporarily. A trailer has none of these luxuries, weighs a lot more and therefore think that the different tire sizes on the same axle cannot be good.

Just my thoughts from reading articles from people smarter than me that have described why this is not good. I can't provide any links but if we think about it, this makes more sense than keeping different size tires and capabilities for my behemoth trailer.

But like what I've learned from the MOC, one can do whatever they want, but just know what you're doing and accept what happens! I have since mentally added the corollary, but if things break under normal operating conditions, why provoke it? My past tire problems have never occurred with 50 miles of a long term solution.

[DonandJudy_12]

It seems to me that the only difference would be the smaller tire will rotate more rapidly than the larger tire- What difference does that make on free-wheeling tires? It certainly would not effect trailer braking in my estimation- Just remember, if you use an ST tire on the ground, the maximun safe speed [if there is a "safe " speed ] is 65- JMHO- Don

[dieselguy]

I'm gonna shut up after this reply ... really. The topic is about a spare tire ... A spare is something to get you down on down the road to a place where you can get whatever issue resolved with the regular tire / wheel combo. Hopefully there will not be a need to leave it on for another 5000 miles, so I really don't understand all this spilled milk over the possibility of running a tire that's maybe an inch less in diameter. It's going to temporarily rotate, track, and hold its share of your fiver just like the other 3 are doing all the while doing it's job of being ... a spare. The only good point of having a high dollar spare was mentioned and with chagrin, I'll have to agree. If you're in the boonies, you'll be hard pressed to locate a 614 ... but then again, your spare is there to get you out of the boonies. The gentleman from Good Sam's had better not spend an afternoon gandering at tractor trailer tires on I-70 ... he'll regularly see quite a mismatch of rotating rubber under the semis.
Headed to the kitchen to take a couple of "Happy Camper" tablets ... Dieselguy
PS ... Art ... there is no need to worry about the lack of a differential on a trailer axle, the wheels are completely separate rotating asssemblies.

[bncinwv]

Can I get more details on the "Happy Camper" tablets??. By the way, my spare is a 614, and if I have to use it, I truly hope that it will get me to my destination, where then I will worry about getting the failed one fixed! Traveling with a crew cab full of women is no time to be sitting at a tire store trying to get emergency service. That is my opinion only based on very practical experience!! Hee Hee!!
Bingo

[pineranch]

I must apologize to the folks from California and Oregon for my earlier comments. It appears we to have our share of 1d10t in Florida. Decided to split the difference and bought a Sam's 235/85 16 as a spare. Sam's had a 2 hour wait to swap so I took it to the Walmart across from our house. The same place that installed my 614's. Manager insisted they must balance any tire they mount and wanted to see my wheel. Saw the steel wheel and Marathon that clearly states "for trailer use only". Now he states that they cannot and will not mount a car tire as a replacement for a trailer tire. Took it to our Goodyear store and for $10 they did as I asked. When you don't have any skin in the game, profits really don't matter.

Mike