Carrying a Spare.... Underneath?

Topic: Carrying a Spare.... Underneath? (Read 1678 times) previous topic - next topic

Re: Carrying a Spare.... Underneath?

Reply #25 – October 04, 2017, 02:12:02 pm

All of the comments here are helpful.

My experience regarding flats/tires issues is that they are indeed uncommon on a tow vehicle, much more likely on a trailer or a towed vehicle. That does not mean such a problem couldn't occur, and the insurance policy seems worth it to me. I have experienced more than my share of exploding trailer tires. The first time was on "new" tires, and I was not carrying a spare. Never again!

The concept of carrying the spare on the front does not appeal to me, because I believe that it ruins the aesthetics of the coach. Certainly, I could rig something up that would be sturdy and safe, I just don't think I'd like the look. As for using a receiver mount like the Roadmaster unit linked by stump, there are issues. That specific one would not be up to the job, according to the specifications. The oil fill and dipstick are behind the side gate on my rig, not a factor. However, I intend to do some towing, and a "stacked" or extended receiver is less than optimal, with reduced weight/load capacity. But the real problem I see is that the spare would be subjected to zoned heat cycling, and at temperatures significantly higher than seen during normal use. Inconsistent or excessive temperature heat cycling is the killer of an otherwise good tire.

As a habit, I use an infrared no-touch heat gun to check things out every time I stop after an extended drive segment. The highest tire temperature I saw during the 2K+ miles I drove to get home from where I found the GV was on the order of 120 degrees. That was on a front tire, after a curvy descent from altitude. The rears stayed cooler than that, and run within 5 of each other.

(As an aside, yes, I also checked brake temperatures on the trip, the coach had been sitting for a while, and I was concerned about sticking/dragging calipers. One groans at low speeds in stop-and-go traffic, which I have decided is pad chatter. Temperatures of rotors and calipers are consistent between left and right.)

The 295 tire mentioned should be way too big for this coach. All of the research which I did prior to buying the FT, and looking at tires led me to believe that there would be fitment problems with even the 255's. Rim width and dual tires sidewall proximity were issues. The Toyos are about an inch smaller in diameter than the 9R. That does not bother me a bit. The effects are slightly increased wheel RPMile, and also engine RPM at the same speed. No big deal. This coach seems to really like cruise control at 65 MPH. They handle well, stability is good.

Before I will be able to "play" with the FT, my wife has indicated that I must accomplish a honey-do list first. Likely that I will not get to working on the underneath carrier until spring. But it was the first thing that came to mind as a way of breaking the ice for me on this list. Yes, I am a DIY kind of guy.....

Thank You, Everyone!

Re: Carrying a Spare.... Underneath?

Reply #26 – October 04, 2017, 02:22:16 pm

I don't know about clearance issues with body and/or suspension components, but the 6.75" Alcoa rims have been successfully run with 255/80R22.5 by many, many of us.

You might check with other ORED owners, as that would change your effective drive axle ratio, and with the 8.2 DD, you don't have a lot of power to spare.

Re: Carrying a Spare.... Underneath?

Reply #27 – October 04, 2017, 02:31:19 pm

My advice to customers long ago(30 years) was to carry a spare in the 19.5 sizes as the cut rock roads would cut the tires sidewalls as the tire leaned over in corners. A few 8r/22.5. Had the same problems. No reports of current tire issues even in Alaska.

Roads were really bad 30 years ago there and had a few customers build front shields to stop broken windshields from the opposite way high speed trucks.

Re: Carrying a Spare.... Underneath?

Reply #28 – October 04, 2017, 04:36:03 pm

Quote from: wolfe10 – October 04, 2017, 02:22:16 pm

You might check with other ORED owners, as that would change your effective drive axle ratio, and with the 8.2 DD, you don't have a lot of power to spare.

Going with a slightly smaller tire raises the effective numerical axle ratio, providing increased torque multiplication. A taller tire would theoretically improve fuel economy, but cost acceleration.

In any case, the tires which are on it are NEW, and will remain there a long, long time, unless something drastic happens to change that situation.

O/T
I can't complain about the fuel economy with this setup. I tracked it using the miles traveled between fill-ups, divided by the gallons put in. I now expect that it will settle down somewhere right around 10 MPG, maybe a little higher. Probably a bit lower, if I tow. The issue with being reasonably precise there is the %&#%*@%** filler neck for the diesel. That darn thing is an abomination, and I can't see how anyone could stand dealing with it at every fuel stop for years and years. I never was able to add fuel even once without spilling some. One time, the nozzle popped out mid-fill. Fortunately, I was standing right next to it. Unfortunately, some got on me. Getting a consistent fill level is impossible. The fuel filler situation is actually higher on the priority list of items to address than the spare mounting location.

Re: Carrying a Spare.... Underneath?

Reply #29 – October 04, 2017, 05:02:10 pm

That is where your MPG should be.

Re: Carrying a Spare.... Underneath?

Reply #30 – October 05, 2017, 06:36:46 am

Anyone want a two year old 295/22.5 tire? I haven't carried one for 135,000 miles, but decided to buy one before the Alaska Motorcade. A bunch of us did. No one had a tire problem.

Re: Carrying a Spare.... Underneath?

Reply #31 – October 05, 2017, 07:33:09 am

Quote from: amos.harrison – October 05, 2017, 06:36:46 am

Anyone want a two year old 295/22.5 tire? I haven't carried one for 135,000 miles, but decided to buy one before the Alaska Motorcade. A bunch of us did. No one had a tire problem.

Amos take it to any truck stop you will sell if real fast to a owner operator

Re: Carrying a Spare.... Underneath?

Reply #32 – October 05, 2017, 09:08:15 am

Alan, here is some user feedback ;Tires for my 88 ORED, with 7.5 wheels

Based on this. I just bought 6 new 295/75/ Samson/Advance tires. The model 116 or 283 are very well regarded. I like the smooth outer rib for noise and resistance to feathering. Load H rated . They are 39.5+- in tall and a little narrow at 8.5 in tread width . All tires are not the same in the same size designation.
I will mount these up in the next few days. I also will change the rear shox and adjust my rear wedge brakes.

I would assume that we have the same chassis and body , wheel wells etc. I sit close to the body only when air is dumped.
Yes, I would totally use up the tires that you have if you can tolerate the dynamics. In my case i want to drop the cruise RPM to 2400 as we are doing some hefty miles next summer . I really like the Samson 255/70/ tires but the PO flatspotted two rears along with the speedo being off and such I opted for new.

Re: Carrying a Spare.... Underneath?

Reply #33 – October 05, 2017, 09:17:59 am

295/75R22.5 on 6.75" wheels???

Re: Carrying a Spare.... Underneath?

Reply #34 – October 05, 2017, 09:21:51 am

I dont know what size wheels he has. I have 7.5.
FT went smaller latter?

Re: Carrying a Spare.... Underneath?

Reply #35 – October 05, 2017, 09:23:53 am

Yes, Foretravel used both 6.75" and 7.5"

So one needs to check-- easily done by looking at the rear outer where that information will be stamped.

Re: Carrying a Spare.... Underneath?

Reply #36 – October 05, 2017, 10:46:37 am

Here is an excellent tire size calculator. You can compare old/new size with revolutions per mile, percentage, etc, etc. Just type in your tires sizes and hit "calculate."

235/80-R22.5 vs 295/75-R22.5 Tire Comparison - Tire Size Calculator | Tacoma...

Pierce

Re: Carrying a Spare.... Underneath?

Reply #37 – October 06, 2017, 01:29:43 am

Mike,
Using the calculator linked by Pierce:
Those tires would be GIANT on my GV! A tire 4 inches taller would not fit well at all, I don't think. The Toyos are indeed about an inch smaller in diameter than the 9R which was spec'd at the time of manufacture.
Note that my FT has the 6.75" rims, and does not have an air suspension. It rides well, I think, on the springs setup, at least when compared to motor homes which I have driven or ridden in previously.
I really see no need to worry about reducing the engine speed at cruise. In the 2300 miles which constituted my "maiden voyage" driving it, I found that the DD hums along at 2400, with the speed control set at 65. On cruise, it seems to handle most hills well too, holding within a couple of MPH of the selected speed. All of the information I was able to garner regarding the 8.2 indicates that it works better spinning than lugging, so dropping the RPM does not seem like it would be needed or advisable.

We're getting a bit of topic drift here, which is how conversations work well. I am out for the weekend anyway, so what I'll say is that when I get an idea as to whether I might be able to mount/carry my spare underneath, I'll post back. That means crawling under with a tape measure. Sounds like fun, eh? It is actually pretty nice and peaceful under there, looking at all the HD stuff which supports the house I get to drive around in.

Re: Carrying a Spare.... Underneath?

Reply #38 – October 06, 2017, 09:34:26 am

Quote from: ILikeToTravel – October 06, 2017, 01:29:43 am

It is actually pretty nice and peaceful under there, looking at all the HD stuff which supports the house I get to drive around in.

I was "working" on the air system under the front of our coach one balmy spring day, reclining on my "low boy" creeper with the nice padded head rest. My wife came to see how I was doing, and found me sound asleep and snoring loudly. She said she was tempted to hit the Hadleys to wake me up, but thought better of it (thank goodness). Instead she "kindly" kicked my feet repeatedly until I regained conciousness.

Re: Carrying a Spare.... Underneath?

Reply #39 – October 06, 2017, 09:44:09 am

Quote from: Chuck & Jeannie – October 06, 2017, 09:34:26 am

I was "working" on the air system under the front of our coach one balmy spring day, reclining on my "low boy" creeper with the nice padded head rest. My wife came to see how I was doing, and found me sound asleep and snoring loudly. She said she was tempted to hit the Hadleys to wake me up, but thought better of it (thank goodness). Instead she "kindly" kicked my feet repeatedly until I regained conciousness.

Well, the good news is that if you were working on the air system, the Hadleys would NOT have disturbed your beauty sleep!

Re: Carrying a Spare.... Underneath?

Reply #40 – October 06, 2017, 01:18:21 pm

I have to admit, I was hoping that more GV owners would post their tire sizes and increase the Database. I doubt that the GV bodywork changed. The fender sizes ,wheel arch sizes,etc ,just doesn't make sense for such a small company to change molds to accommodate the minor variances of editions.

Re: Carrying a Spare.... Underneath?

Reply #41 – October 06, 2017, 03:07:47 pm

My rear rims are 22.5 x 8.25 with 15 degree DC. And I run 295x75 22.5 Firestones .

Re: Carrying a Spare.... Underneath?

Reply #42 – October 06, 2017, 03:32:08 pm

Alan

Your 8.2 is a higher speed diesel than the 8.3 Cummins and the 9 liter Detroit so it will be happy at the RPMs you quote. They are known for good fuel mileage. No worry about lugging any coach with an Allison as it makes it pretty foolproof.

Our U300 has 295/75-22.5 tires all the way around. I had an 11.00 R22.5 for a spare for a short time. If they were used all the way around, they would interfere with the airbags up front. Our 295s occasionally slightly touch the airbag mounting plates but nothing to worry about.

Pierce

Re: Carrying a Spare.... Underneath?

Reply #43 – October 06, 2017, 03:58:26 pm

Pierce,

Do the tires hit only at maximum cut angle? If so, that is EASILY adjusted on the Sheppard M100 steering box. All you need is a small standard screwdriver.

Re: Carrying a Spare.... Underneath?

Reply #44 – October 06, 2017, 05:59:25 pm

Quote from: wolfe10 – October 06, 2017, 03:58:26 pm

Pierce,

Do the tires hit only at maximum cut angle? If so, that is EASILY adjusted on the Sheppard M100 steering box. All you need is a small standard screwdriver.

No, only when the coach is leaned over like an elevation change right side vs left side while turning. Just a little metal polishing with zero contact to the airbag itself. No rubber dust, noise, etc. In 40K, no sign of contact on the tires. I was curious at first but don't even think about it now. If I can ever duplicate the condition, I'll shoot a foto.

Pierce

Re: Carrying a Spare.... Underneath?

Reply #45 – October 06, 2017, 07:49:51 pm

Thankyou Andy and Pierce,
I fit the first 3 today. They fill up the wells. With no air, the clearance is about 1 finger at the closest points. I also swapped the outboard rear stems to the short style for easier filling.

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