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[GMCnet] Help with another tire question [message #280524] Mon, 22 June 2015 19:09 Go to next message
Advanced Concept Ener is currently offline  Advanced Concept Ener   United States
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I have very old Michelin XPS rib tire. Look good but 13 years old. Coach is 28 ft stretch with about 1000# of excess steel welding in front of frame. Don't know coach weight but guess 14000#. Think I could use the extra load capacity of 245 over 225 width. Alcoa wheels. Would like better traction than just summer tires but don't want high noise. Reliability is much more important than first cost. I would like the opinions and recommendations of the experts.

Jon Darcy ACES
North Jersey 76 stretch, flares, 4 bag, Alcoa's, bunkhouse,MAC Dash
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Re: [GMCnet] Help with another tire question [message #280528 is a reply to message #280524] Mon, 22 June 2015 19:34 Go to previous messageGo to next message
tphipps is currently offline  tphipps   United States
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Get coach weighed. Be a good starting point. Then consult a tire size and pressure chart to actual weight at each end.
Tom, MS II


2012 Phoenix Cruiser model 2552 KA4CSG
Re: [GMCnet] Help with another tire question [message #280550 is a reply to message #280528] Tue, 23 June 2015 04:12 Go to previous messageGo to next message
Mr ERFisher is currently offline  Mr ERFisher   United States
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Some details
http://www.gmcws.org/Tech/TireSafety/TireSafetyPresentation.pdf
Erf

On Monday, June 22, 2015, Thomas Phipps wrote:

> Get coach weighed. Be a good starting point. Then consult a tire size
> and pressure chart to actual weight at each end.
> Tom, MS II
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Re: [GMCnet] Help with another tire question [message #280551 is a reply to message #280524] Tue, 23 June 2015 06:07 Go to previous messageGo to next message
Ken Burton is currently offline  Ken Burton   United States
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Well here is my opinion. Going to a 2.45 size tire will screw up your final drive ratio. If you have a stock 3.07 final drive, the tires will reduce that to something even lower. Do you want that with a 14,000 pound coach?

Using a 2.25 size LRE tire will give you a possibility of 5360 pounds on the front end and 10,720 on the rear. For a total of 16,080 pounds total if I did my math correctly. On a normal GMC when we weigh them we usually see right around 4000 pounds on the front so adding your extra 1000 pounds puts you at 5000 which is under the capacity of the 2.25 tires. If you need extra traction, I would look at an AT type tire. I have Kumho KL78's which are an AT type tire. They are great on wet grass. Also I just bought some BFG AT type tires that are made in the USA. I can not give you a recommendation on them as I have not even installed them on the coach yet. I bought the BFG's because the price was right. So I now have a mix of Kumho and BFG AT type tires.

Good luck on your decision.

Get your coach weighed so you know for sure what you are dealing with.


Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana

[Updated on: Tue, 23 June 2015 06:08]

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Re: [GMCnet] Help with another tire question [message #280581 is a reply to message #280551] Tue, 23 June 2015 16:58 Go to previous messageGo to next message
A Hamilto is currently offline  A Hamilto   United States
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Ken Burton wrote on Tue, 23 June 2015 06:07
Well here is my opinion. Going to a 2.45 size tire will screw up your final drive ratio. If you have a stock 3.07 final drive, the tires will reduce that to something even lower. Do you want that with a 14,000 pound coach?

Using a 2.25 size LRE tire will give you a possibility of 5360 pounds on the front end and 10,720 on the rear. For a total of 16,080 pounds total if I did my math correctly. On a normal GMC when we weigh them we usually see right around 4000 pounds on the front so adding your extra 1000 pounds puts you at 5000 which is under the capacity of the 2.25 tires. If you need extra traction, I would look at an AT type tire. I have Kumho KL78's which are an AT type tire. They are great on wet grass. Also I just bought some BFG AT type tires that are made in the USA. I can not give you a recommendation on them as I have not even installed them on the coach yet. I bought the BFG's because the price was right. So I now have a mix of Kumho and BFG AT type tires.

Good luck on your decision.

Get your coach weighed so you know for sure what you are dealing with.
I started to do the same math. But it is not "valid". The 1000 pounds on the front is to compensate for the weight added BEHIND the rear wheels, which takes weight off the front (and puts that weight on the rears). That thousand pounds is to restore some weight to the front, so the front is probably not overloaded, although the only way to tell would be to weigh it. The rear almost certainly IS overloaded.

My first reaction to the original post was:
"Buy the 26' GMC that Matt has and put it back in service with all the goodies from your stretch, and use the stretch for a parts unit. The stretch wasn't done right for weight balance, or probably anything else (braking balance, structural, etc.). Adding 2 feet off the back is the wrong way to do it. It should have about 14 - 16" to the back and 8 - 10" in front of the rear wheels. Then it wouldn't need that weight added to the front for traction. So take it out of service sooner rather than later." My $.02.
Re: [GMCnet] Help with another tire question [message #280585 is a reply to message #280524] Tue, 23 June 2015 19:02 Go to previous message
jhbridges is currently offline  jhbridges   United States
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Whether or not the coach is taken out of service, I'd take a set of 13 y/o tyres out yesterday.

johnny


Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons. Braselton, Ga. I forgive them all, save those who hurt the dogs. They must answer to me in hell
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