Tire Design

[blueblood]

I have rubber manufacturing experience having been President of a Tier 1 supplier to auto companies for rubberized products and solid tires for others. However, not auto/RV type tires per se. Long way of saying I understand rubber compounding issues. My question has to do with other issues (I think). Owners of a Class A motorhome have been bitching about very rough ride for several years now. The solution proffered is to get the manufacturer to change out the tires from 275/70R22.5 LRJ to 275/80R22.5 LRH on the basis that the higher sidewall improves the ride. Owners who have been given the new tires or shared in the cost of change out report improved ride. I'm a doubting Thomas on this one; I suspect psychological factors at work. I can't see a small change of about an inch in sidewall and possibly a 5 # reduction in tire pressure doing much of anything but maybe the load rating is a factor.  Does anyone have tire building experience to be able to comment on the possible improvement ??

 

[Jim Godward]

Leo,

On Diesel RVs list on Yahoo, there is a guy,  Neil LeKander, who I believe is a retired tire engineer.  I would ask there and see if he can help.  I will be interested in any response you get.

 

[BernieD]

On Diesel RVs list on Yahoo, there is a guy,  Neil LeKander, who I believe is a retired tire engineer.  I would ask there and see if he can help.  I will be interested in any response you get.

Jim

After Neil retired from the tire company, he was involved in setting up A-Weigh-We-Go. Did most of the west coast weighings until he retired again a couple of years ago. If Neil says it, it has to be so 

 

[John From Detroit]

I can't see a small change of about an inch in sidewall and possibly a 5 # reduction in tire pressure doing much of anything but maybe the load rating is a factor.  Does anyone have tire building experience to be able to comment on the possible improvement ??

Well,,, I can't comment on the difference either mine came with 22.5" mitchlins so I don't know if there is any difference.  I expect the RV to ride more like a truck anyway.

Now to the point of this post.

Remember the Ford Explorer fiasco a few years back, The new "Roll-a-matic"  Here is what *I* think happend,  this is a mix of fact and theory.

Enter Mr. Yuppi, he's newly married, one in the oven as they say and he decides he needs to trade in his flashy sports car for a "Family Wagon"  Well the family wagon of the decade was the SUV (Still is) and so he gets the Explorer.

Now, understand he's driven mustangs or Firebirds all his life and has no idea of what's involved with a truck.  but still he's got one now, and what's worse it is a short, narrow wheel base with too much body atop too small a chassis.  That there is more.

Ford, knowing folks bought these as cars instead of trucks, suggested running the tires FIVE POUNDS LOW.

That's right, it was the five pounds that caught my eye

Now,,, At the last service interval the technician missed something (Tire pressure check) and Mr. yuppie has no clue as to how things work so he figures "New tires, don't leak" so he's never even THOUGHT of checking the pressure. 

Well, new tires do suffer molecular migration and the pressure in those tires is no longer 5 lbs low.. In fact ti's closer to five pounds PERIOD.

Now Mr. YUPPIE is heading down the road at 80mph 65 car 55 truck) and he hits a pot hole (or other defect/object in the road) what does the rim do... Right through the sidewall  BAND sudden tire failure.

What does Mr YUPPIE do.. Stand on the brakes with both feet of course

What happens next?  One less idiot in the world as he rolls over and dies.

What should he have done  (Someone please add the link to the Mitchlin flat tire video)

 

[blueblood]

Leo,

On Diesel RVs list on Yahoo, there is a guy,? Neil LeKander, who I believe is a retired tire engineer.? I would ask there and see if he can help.? I will be interested in any response you get.

Got a great answer from him today. I'll e-mail it to you if you are not a member of the Diesel RV list.

http://autos.groups.yahoo.com/group/Diesel-RVs/message/69902

 

[Jim Godward]

Got it, read it and agree with you.  He does a great job of explaining things.

 

[BernieD]

Got a great answer from him today. I'll e-mail it to you if you are not a member of the Diesel RV list.

http://autos.groups.yahoo.com/group/Diesel-RVs/message/69902

Leo

Thanks, I saw your post and Neil's response.

 

[2006F350]

To add to John In Detriot theory (very good one at that), also Mr Yuppie feels that since his new vehicle is a truck, and trucks can carry anything and everything you can put in or on them, so he now proceeds to put 1000Lbs in the backend of a vehicle that has a max carry capacity of 500Lbs, then hits the freeway.

Larry

 

[rankjo]

Will someone please post the message that is at this address
http://autos.groups.yahoo.com/group/Diesel-RVs/message/69902
I have tried to access it but Yahoo gives me the run-around as a Canadian user.
It seems like a very worthwhile piece of info, so it would be a great blessing if someone would shortcut the bullsh**

 

[Tom]

Re-posting of entire messages from other forums or boards without permission isn't allowed, but a synopsis would be fine.

 

[rankjo]

There is something strange going on here.
I just found a post (#8) which is posted in my name (Rankjo), but I did not post that message.
Rankjo

 

[Tom]

rankjo,

Does someone else have access to your computer?