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Bambi_Bandit · 11-17-2008, 11:04 AM

During the last campout, 62 Overlander noticed a bulge on the front curbside tire. The cords had separated and resulted in the tell tale "bulge" and crowning on the tread...

These are factory 15" marathon tires that came with the Cosmo when we received her from the factory last July. Based on our calculations on the mileage on the trucks towing her and also adding the mileage for delivery from JC to Weatherford, we estimate the tires had no more than 25K miles on them.

I'm not going to go into bashing the brand or the country or origin, but will say that my motivation to move to 16"s were based on construction, design, and load rating of tires available for that size.

With 62 Overlanders help and Artstreams guidance, I decided to spend the money to purchase (5) HiSpec Series 5 directional rims and (5) Michelin XPS Rib tires.

Series05

Michelin Americas Truck Tires XPS RIB® Page

I purchased the rims and tires from Discount Tire at the following prices:

Rims only (16x7 0 offset 6x5 bolt pattern) $100 each.
Tires (225 75 R16) $249 each

Prices included install but not the high pressure valve stems which I will go into later.

Bambi_Bandit · 11-17-2008, 11:41 AM

I went with the HiSpec wheels, after researching their reliability and safety. I would have loved to find a sold forged aluminum wheel like Alcoa or similar, but at what point does $ and safety become crossed in overkill?

The HiSpec wheels are cast and made in China, but are 3200lb rated at 85 psi. The clearcoat is warrantied for 1 year, but at this point, I've found a good wheel shop in Austin to refinish rims at a reasonable price so I'm not gonna stress on the finish anymore. (I have to remember I have an Airstream that has some corrosion on various parts on her anyways, why stress on the wheels now?)

In speaking to HiSpec, I was forewarned to use stick on weights during the balancing and use a thin walled socket and hand install the lug nuts, as most of the damage they find are from the initial install with the clearcoat edge of the lug nut holes damaged from an install. I did find this to be true that the you must use a thin wall socket. My 4 way tire iron worked on the factory rims, but not these. I needed a 3/4 deep socket from Sears/Craftsman to start the lugs and torque them down.

Tires were selected for the weight capacity (although with the current factory Dexters at 3800lb each I am currently limited to the axles I have). I do have plans to up the axles to 4100 or even 4400 lb later with the 35 degree angle, but that will be done only when I have extra $ (never) or when the current axles begin to show sag.

Based on my GVWR of the trailer, I should be at no more that 7600 lbs. With that in mind and based on the tire pressure weigh capacity, a pressure of 50 psi would give me a capacity of 1940 lbs per axle end, (7760 lbs) so anything over 50 would result in a capacity that was really past my current axle limitations anyways. Since I have (not always) run a bit "heavy" with full loads of cargo, water, and sewage, I figure a psi of 50-55 will be plenty for now.

Another reason the tires were selected was due to the research on their reliability. Although I am sure it has happened, I could not find a documented case on the internet where this tire had a blowout. I am sure you can cause a blowout from certain road hazards, but I was unable to find one where a blowout occurred for "no readily apparent" reason. My research did find that these tires ran cooler as compared to the marathons on the same stretch of road in same heat / and load placed on them. Additionally, the steel belt construction on the sidewalls will better handle the "sideways scrape" when making sharp turns on the tandem.

These tires are retread-able, but I would never do that. I will plan to run them no more than 4 years, and replace them even if tread remains.

**moosetags** · 11-17-2008, 12:13 PM

Kevin, thank you so much for this insight. I am in the throws of the same dilemma with Lucy, my '05 25FB. I had three blowouts with the OEM Marathons. I went to Maxxis 8008, Load Range E's. They did really well for about 25,000 miles when one of them lost pressure due to ply separation at the crown of the tread. I replaced the the bad Maxxis with a Carlisle 10 ply (E), and I am in the process of deciding what to do, as I am fearing that the remaining three Maxxis will follow suit shortly.

Your posts have been very helpful as I have been considering going to 16" wheels. I do have a couple of questions, though.

I've looked at both your tires and your rims on line. Are the XPS Ribs 10 ply? From strictly a looks standpoint, I like the Series 03 and Series 04 better, but I notice that they have an 8mm and 5 mm offset, repectively in the 16x7 size. Did your research show that these would also fit?

I would love to see a picture of your new tires and rims installed on the 27FB.

Brian

fr8tshaker · 11-17-2008, 12:19 PM

Hi Kevin and Prim,

I think you will be alot happier with the Michelins. As you know we had to problems with the Marathons with less than 5K miles on the trailer.

The reason Stan and I did the axle change on our relatively new trailer was the loss of CCC we would have encountered after adding the 2nd AC, 8 optima batteries, solar panels, inverter, etc.

As you already know, we are FTers and the weight of these additions would have reduced our CCC substantially. Our original CCC was 2180 lbs. After the axle change and additions, JC recertified our unit for a 2500 CCC. The original GVWR was 11500 and now it is 12600. This was a crucial improvement for us. I know I still have to watch the CGVW of my TV, which I do.

It was great seeing the two of you again. I am sure you will enjoy your latest upgrade.

Happy Trails, 'shaker

BTW- We are still at home due to Stan having a bug. And speaking of bugs, are still finding happy and healthy lady bugs in our AS.

Bambi_Bandit · 11-17-2008, 12:28 PM

A quick glance at the wheel wells showed that I would have more clearance between the front wheels and "fender / trim" than the rears, which means I had 2 choices:

spend more $$ to replace axles with a 35 degree angle
trim some fender / wheel well area

With the unexpected 2K I had invested in the wheels and tires, I opted to stick with the existing axles and figure out what and how to trim.

As you can see from the pic, one is with the OEM marathon, the other is dry fitting the new rim and tire.

(Sorry for the quality of the pics - I forgot the camera and all I had was my phone....)

Bambi_Bandit · 11-17-2008, 12:47 PM

In looking at some of the other newer wide body Airstreams that were in my storage facility (all this is done at the storage lot), I noticed that even a 2008 25FB had varying amounts of clearance between the tire and wheel well lip/trim. Granted some needs to take in account the wear of tire, but all in all - it all varied from 2 fingers to 3 fingers (each of my fingers are about 1/2", and I forgot the tape measure during this run).

So, in order to be more "scientific" and "consistent" with what I already had, I aimed to get the tape measure with the goal of trying to keep the same amount (or more) of wheel clearance I had with the original marathons.

Note that for top clearance, (top of wheel to inner fender ceiling) I had a little over a closed fist of clearance, so I was not worried about any clearance there. Changing the rim and tires to 16"s with the factory axles would only increase my outside diameter from 28.3" to 29.4"m so I was not loosing too much. If I hit anything that causes the wheel to travel up 5-6 inches I have much bigger worries to think about....

So, the bulk of this post will show the clearance between wheel and wheel well lip/trim.

Here are pics of the curb side rear wheel clearance with the new rim and tire:

I forgot to take a pic with the tape measure and the original marathon, but the measurements I had were:

Curb side rear Marathon to wheel well Aluminum trim piece: 1.5"
Curb side rear Michelin to wheel well Aluminum trim piece: 0.5"

fr8tshaker · 11-17-2008, 01:03 PM

Kevin,

Upgrading to new axles with the 35 degree deflection will still create the same tight space between the fenders and tires. Ask me how I know....

Even after changing our axles and wheels, our tires were very close to the fender. We had to have some of the fender nipped off and the trim reapplied also.

'shaker

Gene · 11-17-2008, 01:11 PM

Kevin, I know aluminum wheels are better looking, but did you look into old fashioned steel wheels? They have to be a lot cheaper.

I am also wondering about how much 16" tires bulge outward on bumps and could they touch the trim and get a shave?

Gene

Bambi_Bandit · 11-17-2008, 01:26 PM

I crawled under the trailer and looked at the specific area in question to trim. Keep in mind I have never done any body work before and my tool of choice was a Dremel tool. The last time I used a Dremel was in junior high (please don't do the math) and it was on wood with a pattern guide...

So...with a sharpie pen and a badge as a straight edge, (the card type ones for access to corporate buildings) I measured an inch back from the edge and made a mark. Using that as an apex, I drew a straight line from the existing edge of the banana wrap to the front edge of the trim... I know may not make any sense but another way to word this is to measure an inch back from the closest edge to the tire and then draw a line similar to the existing contours you have...

Note that you do not want to make a straight cut on the aluminum edge trim, bu rather taper and shape the cut such that you have a gradual line that thins down which also allows you enough room to reuse and reposition the factory screws holding the trim further up than prior.

As you can see from the "post surgery" pics below, I have trimmed the banana wrap slightly and tapered the aluminum trim. I now have a little over 1" of clearance between the tire to the nearest trim piece. Plenty of room to roll and deflect (bounce) without hitting...

Lesson learned #1: Note that there are (2) factory screws in place holding the Aluminum trim to the banana wrap. These are originally tuck under such that they are not normally visible unless you bend over to look. Fore anyone performing this surgery, I suggest you remove the top screw (leave the one closes to the end of the trim) and relocate that to the area that will be the new "end" first before any cuts are made. I made the mistake of cutting first, which resulted in the trim piece separating from the banana wrap. This resulting separation makes it difficult to screw back in place so do this first so you wont fight it like I did.

It is quite difficult to drill a hole in the trim piece with one hand while pushing the trim in place with the other... I made one hole thru the trim and missed the banana wrap. The second time I did get the banana wrap, so for now there are 2 screws, but one is decorative.

I think others may find only once screw may be sufficient as well, which is what I did on the street side - to be shown later...

Lesson Learned #2: As mentioned before, my experience with a Dremel is limited, and thus in my inexperienced I used their standard "cutting wheel". This wheel is marginally sufficient in cutting sheet metal such as the banana wrap, but breaks when cutting the channeled tough aluminum trim. I suggest others use the Dremel "EZ Lock" cut off wheels, specifically the 1.5" metal. They last much better than the standard or even fiberglass reinforced ones...

EZ456 EZ Lock 1-1/2" Cut-off Wheels (5 Pack) / Model: EZ456

Lesson Learned #3:

Put down the Dremel when you feel a sneeze coming. The grinding and cutting will result in various particles. I happened to do this on a very windy cold day in Austin this weekend and my allergies got to me. Holding a Sneeze in while holding a Dremel tool with a cutting wheel going thousands of RPMs per minute mid cut will result in a "skip" which causes a slight knick from the rotating wheel to hit the immediate area, such as the banana wrap, resulting in a nice clean "chip like" beveled blemish...

Good thing this is on the bottom and the banana wrap Grey color is easy to get...

Bambi_Bandit · 11-17-2008, 01:41 PM

Quote:

Originally Posted by Bambi_Bandit

Curb side rear Marathon to wheel well Aluminum trim piece: 1.5"
Curb side rear Michelin to wheel well Aluminum trim piece: 0.5"

Correction on my notes:

Curb side rear Marathon to wheel well Aluminum trim piece: 0.75"
Curb side rear Michelin to wheel well Aluminum trim piece: 0.3"[/

Bambi_Bandit · 11-17-2008, 01:49 PM

As mentioned before, the front clearance was far better than the rears, even with the original Marathons. I probably didn't need to trim the front, but what the heck, the Dremel was already out and I was getting warmed up....

Measurements for the Curb side front as follows:

Curb side Front Marathon to wheel well Aluminum trim piece: 1.5"
Curb side Front Michelin to wheel well Aluminum trim piece: 1"

I neglected to take a photo of the "before" trim, but note that I have trimmed only the "lip" of the edge trim piece. The lip is nearly 0.5" in width and extends beyond the trim channel piece, so this was a cosmetic "nip" more than anything, but did result is me gaining back almost all of what I lost...

Bambi_Bandit · 11-17-2008, 01:57 PM

OK - I was now starting to feel like a pro with this tool... perhaps I should play a doctor on TV???

Taking my own advice from the lesson learned on the curb side, I removed on screw of the 2 that attached the aluminum trim piece. I measured the section that needed to be cut and drilled a hole to replace the screw as that would be my new "end" area of the trim.

Measurements are as follows:
Street side Rear Marathon to wheel well Aluminum trim piece: 0.7"
Street side Rear Michelin to wheel well Aluminum trim piece: 0.3"

Marathon shown below:

Bambi_Bandit · 11-17-2008, 02:04 PM

OK,

As in my previous posts I probably did not describe my cut on the rear sections clearly, so below are better pics of the actual surgery on the street side:

Note the relocation of one of the original 2 screws holding the aluminum trim to the banana wrap. This is the screw I advise to relocate first prior to any cuts (after measurements of course). I have elected to use only 1 on this section.

You can see the "cut area" from the view from the outside as well as the wheel well. This is a pretty good visual reference as the cut piece is held in place with my hand.

Post surgery results in nearly 1.25" of clearance. (Same on the Curb side as well)

Bambi_Bandit · 11-17-2008, 02:15 PM

As mentioned prior on the Front, I trimmed only the "lip" of the aluminum trim. Sorry I forgot to take a "before" pic, but this is what the trim piece looks like after the "lip" is removed.

The angled cut is what I removed, so you can get a reference to what was there prior to the cut.

Bambi_Bandit · 11-17-2008, 02:45 PM

I hope this thread helps those considering the change to 16" rims and tires without changing axles. It can be done, provided you are brave enough with a Dremel.

I will plan to do the axle change later in a few years, but for now, this should suffice.

I apologize that I do not have better pics or pics of Cosmo with her new shoes. This project took me 5 hours and by the time I was done daylight was running out and I was too damn sore to hook up the trailer and pull her out. I will post the "completed" pics later.

One other note is that I was able to fit the 16" rim and tire in the spare tire cradle below, but it is tight. You must push the spare all the way till it hits the cross member of the frame to which the bracket is mounted to and then clasp it shut. It is a tight fit but can be done.

An additional closing thought is that I am thankful that this event did occur on my terms versus a blowout on the road. I've never looked at my marathons closely, assuming that the tread was fine and never gave the cords or belts any thought. I figured that pressure monitoring was sufficient.

I have learned that the tread on the marathons were nearly down to the wear bars, which surprised me given the mileage driven. I am also surprised at the irregular wear pattern seen only when removing the tire and rolling the tread thru your fingers. I founds some patches of balding which did not make sense. I have never locked the brakes, so the "patchy" wear may indicate another issue. I did have my axles aligned when I was in Jackson Center in May of this year, approximately 5K miles ago. I do not know if this pattern was pre or post alignment but I will watch my tires closely from this point forward.

This project does also give a person a good opportunity to get "intimate" with your tires and wear pattern, as well as a chance to inspect the brakes and running gear.

Regarding my decision to purchase the rims and tires from Discount tire, they did "meet" my Costco price, however did not fill with Nitrogen. Not big deal to me but they were the cheapest for the rims and did not charge me shipping for them either (special ordered).

So my only negative experience was damage to rims with Discount tire on my car, which they did repair right away. Therefore when the rims and tires came in, I asked the manager to personally mount and balance the tires.

They did use high pressure metal valve stems, however, the model they used were they type that are encased in rubber. I much prefer the ones I had put on my 15" rims which were solid metal that were bolted on the rim. This allowed for a more sold stem with zero movement and made for a great mount for my tire pressure sensors. I will ask to change these next time I rotate the tires.

I'll post the "finished product" on the trailer when I pull her home later this week.

Special thanks to Artstream for his experince and guidence in the project, as well as 62 Overlander who caught this problem before it got worse... Always good to have another set of eyes look at something!

Stephen Mick · 11-17-2008, 03:05 PM

That is impressive, gorgeous, and pimpin'! After having a catastrophic wheel event recently, I'm thinking of going to 16"s also.

Hey, I'm in Austin. Can I use your Dremel? Better yet, if I bring the barbecue and beer…

Bambi_Bandit · 11-17-2008, 03:14 PM

Quote:

Originally Posted by moosetags

Kevin, thank you so much for this insight. I am in the throws of the same dilemma with Lucy, my '05 25FB. I had three blowouts with the OEM Marathons. I went to Maxxis 8008, Load Range E's. They did really well for about 25,000 miles when one of them lost pressure due to ply separation at the crown of the tread. I replaced the the bad Maxxis with a Carlisle 10 ply (E), and I am in the process of deciding what to do, as I am fearing that the remaining three Maxxis will follow suit shortly.

Your posts have been very helpful as I have been considering going to 16" wheels. I do have a couple of questions, though.

I've looked at both your tires and your rims on line. Are the XPS Ribs 10 ply? From strictly a looks standpoint, I like the Series 03 and Series 04 better, but I notice that they have an 8mm and 5 mm offset, repectively in the 16x7 size. Did your research show that these would also fit?

I would love to see a picture of your new tires and rims installed on the 27FB.

Brian

Hi Brian,

The positive outset would push the wheel and tire further "out" than the factory position with - offset. I don think clearance would be an issue but that would require you to do some quick measuring.

Scott at www.trailertiresandwheels.com is very informative and knowledgeable. He knew the right questions to ask (axle manufacturer, model, use of tire pressure monitors, etc). I did not go with him because of the cost of shipping.

They also make the 16' wheel for Airstream's Pan America. The version they are supposed to sell to the masses are a back and polished version whereas the Pan America has the full polished version. I can't remember the offset on that but it looks like this:

Yes, the XPS rib are 10 ply E rated Tuck and RV tire (propelled or not). All steel belted they are a heavy duty tire. Paul (62 Overlander) introduced them to me and I think they are just the ticket, especially because of the steel side wall with the sharp scrubbing turns we have.

Bambi_Bandit · 11-17-2008, 03:20 PM

Quote:

Originally Posted by fr8tshaker

Kevin,

Upgrading to new axles with the 35 degree deflection will still create the same tight space between the fenders and tires. Ask me how I know....

Even after changing our axles and wheels, our tires were very close to the fender. We had to have some of the fender nipped off and the trim reapplied also.

'shaker

That is good to know... I hope they did the axles better than the power management system they installed!!!

I really like your setup, but with a 34, I bet you scrub those tires a heck of a lot more than I do in turns. I think you went with the LTX tires, correct?

I'm glad to get your input. I hope those with later model wide body trailers can get some direction based on what people like you and others have done on the axle and wheels.

Sorry to hear about Stan. Hope he feels better soon.

Prim is also getting a cold too... I think its the sudden change in weather combined with lack of sleep from too much work and stress....

Bambi_Bandit · 11-17-2008, 03:26 PM

Quote:

Originally Posted by Stephen Mick

That is impressive, gorgeous, and pimpin'! After having a catastrophic wheel event recently, I'm thinking of going to 16"s also.

Hey, I'm in Austin. Can I use your Dremel? Better yet, if I bring the barbecue and beer…

No problem on the Dremel. Feel free to swing by and take a look if you want. I live in NW Austin and will be bringing Cosmo home this week.

Paul Mayeux · 11-17-2008, 04:12 PM

Hey Kevin - it looks great. After the trip to Kirkwood, MO this weekend my Marathons are done. Same irregular wear patterns you describe over approximately the same amount of miles. You will like the Michelin XPS Rib, the construction is much more robust than the LTX, and the only one listed in the Michelin RV guide tire selections for 16".

Also, we can modify your chocks like we did on Artstream's. They will fit the 16" tire much better afterward.