Now I'm Spooked

[uncle_bob]

Originally Posted by Tireman9

It's easy to check the timing on warning on air loss. Simply un screw a sensor and see how long it takes for the monitor to sound.

It is true that if there is no sudden change in pressure the sensor may not send a signal for 10 to 20 minutes. ( my sensors cycle on about 8 to 15 min when no change) But report in less than 2 min when there is air loss.

Hi

The gotcha there are the ones that do "energy harvesting" and report more often when in motion ....

Bob

[GettinAway]

Originally Posted by richw46

My 23D AS came from the PO with 4 GYMs, all made in China. I've had the AS for 3 years, no tire problems. they are now 6 years old so time to replace before the next long trip, although they look like they were just mounted. I will replace with either GYMs or the newer ST tire they came out with.

I regularly check tire pressure now and I won't be running 14 year old tires anymore. I do not have TPMS on either trailer.

Now we are talking. I did the same thing. I would expect someone to call you out on this though. Don't you know you are endangering everyone around you?

[Wayne&Sam]

Just check the pressure every day. That's what I did for a few years. They needed to be topped off every couple of days. I got tire of that and when to 16" Michelins. I set the pressure at the start of the season and have never had to adjust it.

[SCOTTinNJ]

Originally Posted by Wayne&Sam

Just check the pressure every day. That's what I did for a few years. They needed to be topped off every couple of days. I got tire of that and when to 16" Michelins. I set the pressure at the start of the season and have never had to adjust it.

Same here.

[switz]

Our 2015 23D International Serenity came with 14" wheels and 14" GYM ST215/75R14C tires rated 1,870 pounds @ 50 psi and were 26.7" in diameter.

I arrived at the selling dealership with 15" SenDel T03-56545T (that match the SenDel 16" wheels on our 2014 Classic) wheels with 15" Michelin LTX (P) 235/75R15 XL tires sidewall rated 2,183 pounds @ 50 psi but have to be derated to 1,985 pounds for trailer use per Federal Regulations:

*******************************
49 CFR 571.110

Tire selection and rims and motor home/recreation vehicle trailer load carrying capacity information for motor vehicles with a GVWR of 4,536 kilograms (10,000 pounds) or less.

S4.2.2.1

Except as provided in S4.2.2.2, the sum of the maximum load ratings of the tires fitted to an axle shall not be less than the GAWR of the axle system as specified on the vehicle's certification label required by 49 CFR part 567. If the certification label shows more than one GAWR for the axle system, the sum shall be not less than the GAWR corresponding to the size designation of the tires fitted to the axle.

S4.2.2.2

When passenger car tires are installed on an MPV, truck, bus, or trailer, each tire's load rating is reduced by dividing it by 1.10 before determining, under S4.2.2.1, the sum of the maximum load ratings of the tires fitted to an axle.

S4.2.2.3

(a) For vehicles, except trailers with no designated seating positions, equipped with passenger car tires, the vehicle normal load on the tire shall be no greater than 94 percent of the derated load rating at the vehicle manufacturer's recommended cold inflation pressure for that tire.
(b) For vehicles, except trailers with no designated seating positions, equipped with LT tires, the vehicle normal load on the tire shall be no greater than 94 percent of the load rating at the vehicle manufacturer's recommended cold inflation pressure for that tire.

*****************************

and were 28.9" in diameter. I already had the Dill 1606-453 TMPS senders mounted inside the tires and added Centramatic wheel balancers as they were installed using McGard wheel lugs and lock nuts. These were attached to the stock 10" brake drums with five lugs that were later updated to 10" auto adjust drum brakes and a complete replacement of all wheel bearings with USA made Timken bearings and races.

So the trailer frame was elevated 1.1" wth this tire change. We had to trim the curb side front wheel opening edge to match the street side opening for tire clearance. 2017 model 23s have stock 15" tires and wheels and supposedly 12" brake drums with six lugs.

The scales weight of our 23D fully loaded for campings:

Camping Ready 23D my scales 9 May 2016 Full water and propane tanks

Tongue………928
Front….1,280……1,246 - total front axle 2,526
Rear…..1,376……1,233 - total rear axle 2,609
Total Axles………5,135
Total Trailer….6,063

The 15" Michelin tires were run at 44 psi on both the earlier 2013 25FB International (we traded the 25FB for the 2014 Classic) and on the 2015 23D.

Even with the reduced load capacity of 1,985 pounds, there is an over 40% safety margin with these 15" Michelins and the ride is easier on the frame.

Another advantage for me was we re-used both the Hensley Arrow hitch and the Tekonsha Prodigy RF brake control system from the 25FB on the 23D. Since both trailers were at the same elevation, the same hitch settings worked with the same tow vehicle on both trailers (a 2007 Mercedes ML320 CDI V6 3.0L turbocharged diesel with now 168,800 miles on it). We do see over 16 mpg towing at 55 mph which is our preferred speed for the small rig.

We swapped out the 15" stock wheels and GYM tires on the Classic as soon as it was parked in our storage unit with the 16" SenDel T03-66655T wheels and 16" LT225/75R16/E LTX M/S2 tires rated 2,680 pounds @ 80 psi and were 29.2" in diameter. These wheels also had the Dill 15060453 TPMS senders mounted inside the wheels and also had Centramatic wheel balancers installed using McGard wheel nuts and lock nuts. We run 73 psi in these LT tires. The Classic was raised 0.45" with the 16" tires.

[Rich W]

Quote:
Originally Posted by richw46
My 23D AS came from the PO with 4 GYMs, all made in China. I've had the AS for 3 years, no tire problems. they are now 6 years old so time to replace before the next long trip, although they look like they were just mounted. I will replace with either GYMs or the newer ST tire they came out with.

I regularly check tire pressure now and I won't be running 14 year old tires anymore. I do not have TPMS on either trailer.

Originally Posted by GettinAway

Now we are talking. I did the same thing. I would expect someone to call you out on this though. Don't you know you are endangering everyone around you?

True, very true. I suggest they not tailgate me as I travel if they are worried about tread separating. I'm normally in the right/center lane at 65-70 anyways, most go around me as soon as they come up behind me so there's lowered risk.

One thing I have noticed is that most of those who seem to have problems with the GYMs are the 30'+ AS, a few with 27's. I think there's a definite weight capacity issue with the 225/75R15 D rated GYMs. My AS isn't here but the same size tires are on my boat trailer and they are C rated. The 23' seems to do just fine on the GYMs, at least mine does.

The GYEs have moved up a notch on load range for each size over what the GYMs are. I'll be replacing mine with those, glad to see Goodyear make the improvement. Speed rating isn't so important for me. I'm retired, I'll eventually get where I'm going.

[GettinAway]

richw46, do you have 15" tires on your 23 now? I'm curious which of the 15" GYEs to go with for my 23. They make a D and an E rated model. I've been meaning to see what the weight rating is for the 14" GYMs that are on it now.

[switz]

To begin with, Airstream literature tongue weights are notoriously low. So as the tongue weight increases, the tire load decreases for the same GVW.

The GVW of the 23D is 6,000 pounds and the Airstream literature tongue weight is 720 pounds. Thus, in theory each of the tires are carrying 1,320 pounds. The real world numbers on my individual wheel scales for my customized 2015 23D are:

Tongue………928
Front….1,280……1,246 - total front axle 2,526
Rear…..1,376……1,233 - total rear axle 2,609
Total Axles………5,135
Total Trailer….6,063

The trailers with 6,000 pound GVW or less could use the GYE ST225/75R15 and using my example numbers above could run as a "B" rated tire at 35 psi which the GYE load tables says 1,760 pounds load capacity.

The 20' models have a GVW of 5,000 pounds and an Airstream literature tongue weight of 631 pounds. The axle is supporting 4,369 pounds. So each tire has to support 2,185 pounds. That same tire listed above with a "D" tire pressure has a load capacity of 2,540 pounds at 65 psi and 2,830 pounds at 80 psi.

The GYE tire chart shows GYE 16" tires that will be substantially larger in diameter then the 15" GYE and clearance could be an issue. The 16" Michelin LT225/75R16/E LTX M/S2 tires are only 0.45" larger in diameter than the original GYM ST225/75R15 tires.

One needs to gain access to the GYE tire specs that include diameter to help in making a choice to go to 16" GYE tires.

Note that while the load capacity does increase with more air pressure, the sidewalls get stiffer as well and can have a negative impact on the ride for the trailer.

So going to 16" would allow for the same loads of a 15" tire at lower air pressures, but then one needs to closely monitor tire temperatures to find the spot where the sidewall flex al that lower pressure does not raise the internal tire pressure to unacceptable levels and thus tire failure.

[Rich W]

Originally Posted by GettinAway

richw46, do you have 15" tires on your 23 now? I'm curious which of the 15" GYEs to go with for my 23. They make a D and an E rated model. I've been meaning to see what the weight rating is for the 14" GYMs that are on it now.

Right now I have the GYMs and they are C rated - 215/75R14 C. They need to be replaced (year 7 now) but it's just sitting in storage so no hurry. When I replace with the GYE I'll use the same size but those are now D rated.

C rating for the 215/75R14 GYM is 1870
D rating for the 215/75R14 GYE is 2150 @ 50 PSI, 2540 @ 65 PSI

(2150? shades of Broderick Crawford and Highway Patrol, Friday night, 8:30 I think. )

[Rich W]

Originally Posted by switz

The GYE tire chart shows GYE 16" tires that will be substantially larger in diameter then the 15" GYE and clearance could be an issue. The 16" Michelin LT225/75R16/E LTX M/S2 tires are only 0.45" larger in diameter than the original GYM ST225/75R15 tires.

One needs to gain access to the GYE tire specs that include diameter to help in making a choice to go to 16" GYE tires.

Available at the Goodyear site:
https://www.goodyear.com/en-US/tires...ce/sizes-specs
Click the + sign by the tire size to get the dimensions

[switz]

So getting the information from the GYE table mentioned above, the "smallest" diameter 16" GYE is 30.8" in diameter while the 16" Michelin LT225/75R16/E LTX M/S2 tires we installed were 29.2" in diameter. That extra 1.6" diameter would be problematic on most Airstreams. The 15" GYE is 28.3"in diameter which is the same as that same model GYM ST225/75R15D.

[GettinAway]

Originally Posted by richw46

Right now I have the GYMs and they are C rated - 215/75R14 C. They need to be replaced (year 7 now) but it's just sitting in storage so no hurry. When I replace with the GYE I'll use the same size but those are now D rated.

C rating for the 215/75R14 GYM is 1870
D rating for the 215/75R14 GYE is 2150 @ 50 PSI, 2540 @ 65 PSI

(2150? shades of Broderick Crawford and Highway Patrol, Friday night, 8:30 I think. )

Thanks Rich. I was up at the farm yesterday and finally looked at my 14" GYMs, and noted the C rating. I'm going to 15" tires so I'll have to decide between the D and E rated 15s. The Es are way more than I need. (6,000 GVWR)
Thanks again.

[Tireman9]

Originally Posted by richw46

Right now I have the GYMs and they are C rated - 215/75R14 C. They need to be replaced (year 7 now) but it's just sitting in storage so no hurry. When I replace with the GYE I'll use the same size but those are now D rated.

C rating for the 215/75R14 GYM is 1870
D rating for the 215/75R14 GYE is 2150 @ 50 PSI, 2540 @ 65 PSI

(2150? shades of Broderick Crawford and Highway Patrol, Friday night, 8:30 I think. )

Isn't that a typo?
GYE ST225/75R15 is rated 2,150# @ 50 psi and 2,540# @ 65 psi

ST 215/75R14 is rated 1,840 @ 50 and 2.200 @ 65

I posted the Load Inflation charts from GY on May 22 GYE and GYM have same numbers since they used the same old formulas.

[Mike G]

Originally Posted by KK4YZ

Hi,

We took delivery of our new 23D just a little over 3 months ago. Of course it has goog ole' GYM's on it. Is the problem with GYM's so bad that I should run out now & replace 'em?
Has ANYONE had a satisfactory experience with GYM's or am I pulling 4 blowouts waiting to happen?

I check tire pressure each day before hitting the road ad look the tires over at each rest stop. Should I get a TPMS and be careful or change these tires out now?

My new 27' has 15" Goodyears that run at 80# cold. One is losing pressure at the rate of >10# in three days. It's in the shop right now, but I'm nervous as hell, and plan on getting TPMS.

[KK4YZ]

Originally Posted by Mike G

My new 27' has 15" Goodyears that run at 80# cold. One is losing pressure at the rate of >10# in three days. It's in the shop right now, but I'm nervous as hell, and plan on getting TPMS.

Isn't 80# a little high for GYM? They're rated at 65# and I've heard of going to 70#. But 80?

[Rich W]

Originally Posted by richw46

Right now I have the GYMs and they are C rated - 215/75R14 C. They need to be replaced (year 7 now) but it's just sitting in storage so no hurry. When I replace with the GYE I'll use the same size but those are now D rated.

C rating for the 215/75R14 GYM is 1870
D rating for the 215/75R14 GYE is 2150 @ 50 PSI, 2540 @ 65 PSI

(2150? shades of Broderick Crawford and Highway Patrol, Friday night, 8:30 I think. )

I must have mixed up a couple of charts for this post, I was looking at several.
C rating for the 215/75R14 GYM is 1870 (correct)
D rating for the 215/75R14 GYE is 2200 @ 65 PSI (now correct)

(Thanks, Tireman9)

[switz]

Run the appropriate pressure for the tire loads.

Cranked up to 80 psi on a lighter trailer gives the trailer a harsher ride.

Since the prior generation GYM was a load D tire = 2,540 pounds payload at 65 psi, there is really no need to go any higher on the air pressure on the GYE tires unless one has a 30' model or Classic.

[Tireman9]

While running TPMS is STRONGLY recommended it is important to remember that those systems ONLY report on air loss and are not designed to nor will they provide advance warning of belt/tread separations.

Sidewall Flex failures (many call Blowouts) are the result or running at speed while air leaks out (hole, puncture, leaky valve etc)

Belt separations take many miles (hundreds to thousands) to develop but many times can be observed improper inspection such as the Free spin inspection video I have posted about.

[GCinSC2]

Tireman9,

I'm running Dill internal TPMS and it reports internal temp.

It did warn me on a trip of a hi temp wheel that was caused by sticking pad on caliper. Pulled over and made field repair and continued trip.

Tire was not source of heat but that saved me more serious repairs.

Yes my rig will have Dill internals unless something better shows up.

Gary

[Mike G]

Originally Posted by KK4YZ

Isn't 80# a little high for GYM? They're rated at 65# and I've heard of going to 70#. But 80?

You are right- the sidewall lists 80 Max, but the tire placard says 65. My mistake!