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toastie · 10-13-2006, 04:21 PM

We are planing a long trip with our 65 Caravel and would like to know what tire pressure I should run with, my tires are Goodyear's ST215 75R14, I presently have them set to 50 lbs..........thanks

bhayden · 10-13-2006, 04:43 PM

Looks like all the 14" tires are Load Range C and rated for max inflation of 50psi.

http://www.tirerack.com/tires/Spec.j...arathon+Radial

I'd run them at 48-50psi measured cold. With anything at all in the trailer you're pushing the limits of the tire.

68 Overlander · 10-13-2006, 04:48 PM

http://www.goodyear.com/rv/pdf/rv_inflation.pdf

clancy_boy · 10-13-2006, 05:16 PM

Quote:

Originally Posted by bhayden

Looks like all the 14" tires are Load Range C and rated for max inflation of 50psi.

http://www.tirerack.com/tires/Spec.j...arathon+Radial

I'd run them at 48-50psi measured cold. With anything at all in the trailer you're pushing the limits of the tire.

Really, pushing the limit? Please explain. I have 15" Marathons on my 66 Caravel - ST225 75/R15 rated at 2250lbs each. The new axle from Inland RV I will be installing on Tuesday is rated for 3000lbs. Two tires = 4500lbs of carrying capacity, well in excess for this trailer. Please let me know what I am calculating wrong. I will be very interested as I plan on staying with the "C" rated Marathons from now on. Almot impossible to find a name brand "D" rated around here. Just spent the better part of today looking and it would be 6 weeks for a delivery.

bhayden · 10-13-2006, 05:37 PM

Your using 15" tires. They have a higher rating than the 14" tires toastie reported having. For the 14" tires the load limit is closer to 1800# each. I'm making the assumtion that dry weight on the Caravel is just shy of 3,000# so figure ~500# or so of "stuff" and you're getting close enough to the rated limit that it seems prudent to get all the load carrying capacity possible from the tires by inflating to max psi.

-Bernie

Toastie ST215 75R14 = 1870 per tire or 3740 total capacity
Clancy_boy ST225 75/R15 = 2150 per tire or 4300 total capacity

The 15" tires give you a much more comforable margin.

clancy_boy · 10-13-2006, 05:44 PM

Whew, I was hoping that I didn't goof, you are right - the 15" have a higher rating. May not be original to a 66 Caravel but that's what was on her when I got her. Bought 3 new rims to go along with the new axle. I will do the complete running gear change on Tuesday. Did't want any errors in my calculations to mess things up.

mustang · 10-13-2006, 05:53 PM

I always run the max on the side wall for fuel ecconomy reasons and I dont want to heat up the side walls. It also aids in manuvers say you have to take evasive action to get out of trouble. I also check tire temp when I stop to get fuel simply with my hand warm is normal.

toastie · 10-13-2006, 08:00 PM

Quote:

Originally Posted by bhayden

Your using 15" tires. They have a higher rating than the 14" tires toastie reported having. For the 14" tires the load limit is closer to 1800# each. I'm making the assumtion that dry weight on the Caravel is just shy of 3,000# so figure ~500# or so of "stuff" and you're getting close enough to the rated limit that it seems prudent to get all the load carrying capacity possible from the tires by inflating to max psi.

-Bernie

Toastie ST215 75R14 = 1870 per tire or 3740 total capacity
Clancy_boy ST225 75/R15 = 2150 per tire or 4300 total capacity

The 15" tires give you a much more comforable margin.

Thanks very much, I will run 48 to 50 psi, the reason for the 14" tires instead of the 15" tires is that airstream put on a new axile and when they installed the shocks they installed to close to the 15" tire's and when on a trip
it blew one on the tires, so instead of changing the shocks airtream put on brand new 14" tires with new airstream cast wheels, this is according to the owner that I bought the trailer from, just a heads up........

SilverToy · 10-14-2006, 01:47 AM

Hello all -

In the voluminous reading I have done here and elsewhere about tires has lead me to beleive that sidewall flex is the sure death of a tire.

Sidewall flex of any source. The post primary source is underinflation, then over loading.

Having the righ ttire for the right application is CRITICAL.

Checking inflations/ temps at EVERY stop is a cheap way to know what is happening with your rubber.

Laser temp guages work Awesome to check both the tires and the hubs with no dirty hands - all in under 5 seceonds a wheel/tire. Compare over a trip to find the normal operating range. Anything out of whack, and if you don't check/change/correct..... you WILL have a blowout!!!!

Inflation check in AM (before heading out) and in the PM (when it's parked) will also add info to the situation.

Even having 1 tire go down - not even flat! - will add HUGE stress to any other remaining tires on that side. Be vigilant!!! Blowouts can cause serious wrecks, and at the very least be a HUGE pain in the *ss, or can even cause serious Checkbook depletion when those panels have to be replaced!!!!

Get good tools to keep yourself up on all that is happening with your rubber, your hubs and be sure to keep inflations even and consistant. All will be well with the world if you do this! Trust, me I know!!!!!!

Axel
SilverToy

Bob Thompson · 10-14-2006, 08:35 AM

SilverToy, I admire your resolve and commitment to monitoring your tires for safety sake! Frankly, I'm too damned lazy to check my tires at every stop. Checking the tires four or five times a day is just way more than I want to buy into. When I set out to solve my trailer tire problems the sole purpose was to get tires which would give me the peace of mind, confidence and durability of the very fine tires I was using on my TV (Michelin LTX M/S).

On my tow vehicle, I check my tires before leaving on a trip, and a few times during a month long trip, and when I get home. When I'm home, I visually check them every couple of days and actually get the tire guage out every couple months. This is what I wanted for my trailer tires and this is what I got with the BF Goodrich Commercial T/A's. You can read all about it in the thread Tires....Tires....Tires. These tires are simply in a class way way above the Goodyear Marathons they replaced. I've towed our 25' Excella nearly 22,000 miles on them to date and their performance has been exemplary in every way. It looks like they will easily go another 50,000 miles. I have to chuckle to myself when I read posts where people say the life expectancy of Marathons is 6,000 to 12,000 miles (and that is with constant monitoring). Instead of constantly looking in the rear view mirror to see if the trailer is having tire problems, I'm watching the road ahead and enjoying the scenery.
Again, I admire your vigilance, really! I wish I could find a way to motivate myself to that level of performance. Seems like the older I get, the lazier I get.

**azflycaster** · 10-14-2006, 08:59 AM

Bob, I am somewhere between you and Silver toy. I do check all my tires before every trip. When I stop I give the tires a kick to make sure that one is not soft and I check for overheating (with my hand).
I have the same tires on my Tundra that you have. What a difference from the originals. I looked at a few sites for more infor on your TT tires, but can not find them in a 15" wheel. What size are you running on your trailer?

Bob Thompson · 10-14-2006, 09:01 AM

I've changed to 16" wheels. The BF Goodrich Commercial T/A's come in 16" and up sizes.

Nye Thatcher · 10-14-2006, 10:10 AM

I have found that if I weigh my rig fully loaded,tanks full, and call the tire company, I don't have to guess. If you are going to a tire with a heavier load, be sure your wheels are designed to take that load. This spec. is stamped inside the wheel. I ran into this problem and had to go to split rims. This was not on an Airstream. I also stay with tires designed for travel trailers. The companies who make travel trailer tires spend a considerable amount of research on this.
Just a couple of thoughts to kick around. Good luck.

Bob Thompson · 10-14-2006, 11:34 AM

BF Goodrich approves their Commercial T/A's for all positions including trailer use. This is easy to confirm. Just call 877-788-8899 during business hours and ask for Customer Service.

herrgirdner · 10-16-2006, 08:16 PM

I noticed on my son-in-law's Prius that it had a wireless tire pressure monitoring system.
http://www.doranmfg.com says they make such a product. Seems like this would be a tremendous improvement, if it works, that is. Has anyone used this product?
regards

golddigger · 10-24-2006, 08:16 PM

I use smartire gen 1 on my trailer. works great. monitors temp and pressure of each tire. you will have blowouts and flats. its a fact of interesting travels. the key is to minimize risk of cascading effects, such as roll or damaged panels. smartire reduces risk of tire problems by giving you live tire status as well as a heads up when things are about to go wrong.

www.smartire.com

gen 1 is out. gen 2 is in now.