Misc Thread VI: Return of the Threadi

[IMBoring25]

For every flat I've personally ever had the slime would have been sufficient, but the OEM tires on my dad's truck had a manufacturing defect that led TWO to develop tumors on a family trip. The spare and the first one to fail were good enough to ride the shoulder to the next exit. Anything other than a puncture and the slime is worse than useless. Wonder how many people have to call out taxis to get to hotels and tow trucks to retrieve their vehicles before the fuel savings cancel out...

[Rope-Pusher]

^ In a clean environment, those might work, but if mud or ice gets in there and sticks it will put the tire out of balance.

I wonder if it would be possible to design them with the same rubber sidewall as pneumatic tires to mitigate that issue.

I think you need the innards exposed to air for cooling. If you walled it off with sidewalls on both sides excessive heat would build up.

[Teamwork]

Follow up question here:

How often do you guys check/inflate the spare? I mean what good is it having a full size spare if the PSI makes it unusable? I've been lucky and the only times I've ever had to change mine was once (it wasn't a full size spare/"bicycle" tire) and it just happened to have close to the recommended PSI. I have had full size spares now and really only check them once a year if even... Just curious so I can get into a good routine. I do carry a cig lighter air compressor regularly, so I don't think it'd be totally screwed but I wonder if these go in and out of psi as regular as tires actually on your car and being used.

[Rope-Pusher]

Follow up question here:

How often do you guys check/inflate the spare? I mean what good is it having a full size spare if the PSI makes it unusable? I've been lucky and the only times I've ever had to change mine was once (it wasn't a full size spare/"bicycle" tire) and it just happened to have close to the recommended PSI. I have had full size spares now and really only check them once a year if even... Just curious so I can get into a good routine. I do carry a cig lighter air compressor regularly, so I don't think it'd be totally screwed but I wonder if these go in and out of psi as regular as tires actually on your car and being used.

While temperature changes can affect the inflation pressures of roadwheel tires as well as spare tires, I don't think there are many situations where air leaks into a tire. It seems the predominant trend is for air to leak out. In my experience, it seems that high-pressure compact spare tires tend to lose more pressure, as a % of their recommended inflation pressure, than road wheel tires do. I think that the higher recommended pressure makes the air more likely to find a way out. Also, the volume (Hey youse kids, turn that music down!) of air these compact spare tires hold is typically less than the volume contained in the road wheel tires, so I think that the same amount of seepage would = a greater drop in pressure.

I've never performed a random survey of tire compact spare tire pressures (yes, I have performed a random survey of road wheel tire pressures. It's easier to just walk up and measure them in a parking lot. You don't have to ask anyone to open their trunk for you.)


I would say, anecdotally, that most compact spare tires I cum upon are only inflated to 1/2 of their rated air pressures.

Yes, we need to alert Donald Trump so he can tweet to the whirled that there will be a crack-down on compact spare tire air pressures by local, state and federal authorities. It's the onliest whey we're going to get people to keep them inflated properly. Maybe he can make it so you can't purchase gasoline unless the spare tire air pressure has been validated within the last 30 days.

[tankinbeans]

I've never checked. Maybe tonight I will just to be on the safe side. I imagine once a month is sufficient.

[theholycow]

But this is why I like full size spares on a matching rim. Easy as pie. My tires have less than 5k miles on them, so diameter difference due to wear isn't a concern. That, and I don't have an LSD to worry about anyway.

...and, of course, you do a 5-tire rotation however often you rotate, thereby keeping wear consistent, not letting your spare rot untested for years on end, and not wasting the treadlife of the spare.

[theholycow]

It just isn't worth the cost and weight savings not to have a spare tire of some sort, and like you point out, having a full-sized spare on a matching wheel adds a significant level of convenience.

Agreed. However, it does let them say "Look, we did something to try to help!"

At least tires are better than they have ever been, and the ubiquity (thanks to an unnecessary but useful law) of TPMS helps attentive drivers avoid the most common cause of failures that can't be fixed by a can of goop.

And addressing some of the other issues:

Slime brand sealant

That's been around for decades. It's one of those gimmicky things that some folks love and use constantly. Its popularity seems to wax and wane. Sometimes I think I'd like to try it for a hard-to-find slow leak, but I don't want to do that to the guys who mount my tires.

spare tire inflation

Don't TPMS-equipped cars (at least those still equipped with a spare) come with a TPMS-equipped spare? Either way everyone should check often, but as long as you have a 12v inflator (which everyone should have!) it changes the issue from "you're gonna be screwed" to "you're gonna take an extra 20+ minutes to change to your spare". At least you can quick change to the spare and drive (not far and not fast) somewhere safer than roadside to finish the inflating.

I've never performed a random survey of tire compact spare tire pressures (yes, I have performed a random survey of road wheel tire pressures. It's easier to just walk up and measure them in a parking lot. You don't have to ask anyone to open their trunk for you.)

This would be easy to do at a self-service junkyard...just try to stick with new arrivals so you get fresh data. Weigh data from crashed cars more heavily than those that were neglected at end-of-life for sure!

[Rope-Pusher]

Just last week, I got called to help my SIL with a flat tire. She was only 2 miles from my house, so I packed an Armstrong Airpump, a floor jack, sockets, a ratchet wrench, a breaker bar and a tire plugging kit and went out to help her.

The tire was flatter than a flounder. I looked all over the exposed tread to find where it was punctured, but found nothing, so I had her roll it backward 2 feet and I looked again. Still I found nothing.

I proceeded to inflate it with the Armstrong Airpump and it lifted about an inch but then I heard the hissing. There were two cuts on the sidewall, about an inch long each, that together formed a flap that was hissing quietly until I pressed on it with my thumb and then the air escaped rapidly - not a candidate for plugging, to say the least. I gave her the bad news that she needed to purchase at least one new tire before I took out her compact spare and mounted it in place of the holey tire. When I checked it, her compact spare was only inflated to 30 psi, so I used the Armstrong Airpump to take it up to the 60 PSI requirement.

I will say that I am usually lucky to find merely a screw or a nail puncturing the tread when I come across flat tires, but I have also had experiences where the sidewall was damaged, or where the puncture in the tread was so large (50 caliber shell casing one time and a rock shaped like an arrowhead another time) that the hole was too large to safely repair with a plug or two.

We tend to think that our personal vehicles will always provide dependable transportation, so much so that we might not even consider allowing in our planned travel time for a breakdown delay, but in addition to thinking about whether you'll be able to get back on the road in a short time after sustaining a flat tire, or whether you'll be stranded alongside the road, wishing you had a spare tire to replace a severely damaged one, think about what you wear when you go driving in your car. In the winter, or when there is rain, you should have clothing in the car appropriate for spending an hour outside the vehicle.

[tankinbeans]

I guess shorts and a tank top are innapropriate this time of year. I do have knockoff Carhart workwear, but it's in the Buick.

[theholycow]

I often think I ought to carry a set of appropriate clothes in my car. Then I load them in and go for years without needing them, then when cleaning I say "Why do I bother hauling these clothes around?" and remove them...then I read a post like that and the cycle begins anew.

I think I might have slapped on a dirty work jacket once while re-hanging my exhaust on the way to the office.

[Rope-Pusher]

All the breakdowns and accidents I've ever had have been unplanned.

Not that I've had many, but there was the time the day after Christmas when I wished that I had told my son to bring a jacket when we drove off on a short errand and ended up on the side of the road as a policeman wrote up the accident report for the 4 cars and drivers involved. Oh, and I was only wearing an open-knit sweater and it wasn't doin' much out there in the wind.

Yanno, a knit cap, a raincoat to repel wind and rain and a fleece shirt for insulation go a long way toward preventing hypothermia.

Speaking of hypothermia, most cases are actually from being out in the rain in temperatures between 32 and 60 F. Tell someone the temp is in single digits and they will prolly dress appropriately, but we tend to underestimate how much more heat we lose when wet due to evaporation and conductivity.

[theholycow]

we tend to underestimate how much more heat we lose when wet due to evaporation and
.

fickset?

[Rope-Pusher]

we tend to underestimate how much more heat we lose when wet due to evaporation and
.

fickset?

Eye ham still sprised that nobody remarked to "When I cum upon a compact spare tire" - I guess Yukon can lead amanda water,....

[potownrob]

It just isn't worth the cost and weight savings not to have a spare tire of some sort, and like you point out, having a full-sized spare on a matching wheel adds a significant level of convenience.

Agreed. However, it does let them say "Look, we did something to try to help!"

At least tires are better than they have ever been, and the ubiquity (thanks to an unnecessary but useful law) of TPMS helps attentive drivers avoid the most common cause of failures that can't be fixed by a can of goop.

And addressing some of the other issues:

Slime brand sealant

That's been around for decades. It's one of those gimmicky things that some folks love and use constantly. Its popularity seems to wax and wane. Sometimes I think I'd like to try it for a hard-to-find slow leak, but I don't want to do that to the guys who mount my tires.

spare tire inflation

Don't TPMS-equipped cars (at least those still equipped with a spare) come with a TPMS-equipped spare? Either way everyone should check often, but as long as you have a 12v inflator (which everyone should have!) it changes the issue from "you're gonna be screwed" to "you're gonna take an extra 20+ minutes to change to your spare". At least you can quick change to the spare and drive (not far and not fast) somewhere safer than roadside to finish the inflating.

I've never performed a random survey of tire compact spare tire pressures (yes, I have performed a random survey of road wheel tire pressures. It's easier to just walk up and measure them in a parking lot. You don't have to ask anyone to open their trunk for you.)

This would be easy to do at a self-service junkyard...just try to stick with new arrivals so you get fresh data. Weigh data from crashed cars more heavily than those that were neglected at end-of-life for sure!

methinks only cars with active tpms systems (can) have the sensor in the spare tire to measure its pressures. passive tpms systems do not use tpms sensors to measure the pressures, and they cannot tell the exact pressures of each tire. one of the trade-offs is that they are much easier to deal with (don't have to put sensors in winter wheels or deal with tpms light). also agreed about the downsides of green slime.

[Teamwork]

methinks only cars with active tpms systems (can) have the sensor in the spare tire to measure its pressures. passive tpms systems do not use tpms sensors to measure the pressures, and they cannot tell the exact pressures of each tire. one of the trade-offs is that they are much easier to deal with (don't have to put sensors in winter wheels or deal with tpms light). also agreed about the downsides of green slime.

Looking at it this way makes it better for our vehicles to have a passive system IMO. If you're going to run a set of dedicated summer performance/winter tire you won't have to worry about the light being on for one of those periods because you can literally just reset it whenever. I literally don't see an advantage of the active system unless you are the ultimate lazy.

I really could probably name the number of people who I know who I've seen/feel confident know how to change a tire on one hand. I remember this notion was also used as a defense for the lack of spares in new vehicles from one auto maker. Valid- it may be.