Michelin XML's

[DavidGB]

Backspacing

Will,
Thank you for going to that trouble! The mystery deepens though. I have one 7.50 R16 tire on a rim with the small width ring lying around. I just went and measured the backspacing on that one and it was 7"! Because the tire is mounted I can't readily confirm for sure that it is a 5.5x16 rim, but that would be my guess. I have measured the rim (bead to bead) width on the rims under discussion and they do measure 6.5". I will have to attempt to take some detail photos this week end and post them.
Thanks again for doing that measuring.
DavidGB

[DavidGB]

Backspacing

I managed to take some photos of one of the rims. Among other things the rim and the ring have 6.50H 16 stamped into them. I would like to hear from folks if they notice anything different (or the same) about their rims vs these photos. Note: When the lock ring is in place it's outer edge is roughly in the same plane as the outside face of the center. This is how I remember the rims on other power wagons I have owned in the past being.

[W_A_Watson_II]

DavidGB,

OK, I need to clarify my early back spacing measurement. It was from my notes and letter to my custom wheel manufacture. (Power Wagon, Budd Bolt Pattern) As the Budd wheel has a large return lip out away from the bead seat, I had measured what is referred to as the "True Backspacing", or the distance from the tire sidewall seat to the wheel to hub surface. That is where my 7" of true backspacing measurement came from. I measured this way because I was going to a modern wheel with a small lip.

I re-measured a wheel, and have attached a photo. The backspacing from the wheel lip to the wheel hub flange is 7.75".

Hope this helps and doesn't add to the confusion.

[DavidGB]

Backspacing

Now I get it!
I measured backspacing based on various "how to measure backspace" sites. I had not come across the concept of "true backspacing" ere now. The pictures you just posted confirm for me that my rims are the same as yours and not some odd balls. By the way, it was pictures of your and Kevin Mienke's awesome MRT custom bead locks that prompted me to consider having them build some rims for the XML's. On a 6.5 x 16 Budd rim you measure a "true" backspace as being from the mounting face to the rear bead seat face which equals 7". I was considering holding that rear bead seat location when submitting to Marsh so as to minimize horizontal clearance issues. I realize that this means the tire centerline would shift outward 1.25" (9"-6.5"/2) and thus have some down side in terms of things like wheel bearing loading and steering force. I don't remember what you (and Kevin Mienke) decided for your builds. I will go back and review those posts. Thanks so much for bearing with me on this.
DavidGB
David

[W_A_Watson_II]

David,

Hey no problem. I had my self scratching my head wondering how we were so different. Always glad to help.

On my backspacing for my 17x10's I went with 7.75" true backspacing, or 8" as most measure from the lip edge. because of the lip size differences, you can see where the use of true backspacing is more accurate in deciding what you want. Mine are therefore 3/4" greater backspacing and with a 3.5" wider wheel, so my tire center line is 1" further out. But because of the larger tires (39.5" vs 35.5" OD) and the steering geometry, this places the tire center contact point close to the stock alignment. I went through several measurements and drawing to decide on the contact point and offset, but then again I tend to over think my designs.

If you need anything else just let me know.

Will

[didget69]

Michelin recommends an optimum 9" rim on the 325R85-16 XML's; 8"-10" is their design range, but I'd be leery of using the 325-series on a 6.5" Budd rim... the 'tuck under' of the sidewalls when mounted on narrow rim makes the tire bulge at the crown.

But roll your own.

Bryan

[DavidGB]

didget69,
I came to that same conclusion awhile back and am waiting until I can have some rims made for the XML's.
See the thread "Michelin XML question" in the 1 ton Power Wagon sub-forum.
DavidGB

[DavidGB]

Michelin XMLs Finally Mounted!

Well it took me awhile but I have got my Michelin XMLs mounted on the '47 WDX. I had Marsh Racing build a set of 9" wide bead lock rims with the stock bolt pattern. I had the rings painted a gold and then since here in eastern Mass. I struck out with finding any tire shops that were willing to mount them for me, I did it myself today. Pretty time consuming. I took a few pictures as I did it and will describe the process I went through. (I should not be considered the last word in this.)
DavidGB

[Gordon Maney]

Beautiful!

[DavidGB]

Bead Locks

First step: Clean tire beads. Next dress the bead and rim contact faces with tire "goo." There are many different recommendations as to what to use. In my case, the Michelins (which are used) had a considerable amount of this awesome black goo in them which I salvaged and used.

Then I set a rim, bead lock face up, on a large pail and dropped a tire on it, forcing the inside bead past the bead lock edge so that the tire now sat with the inside face of the outer bead resting on the rim's bead lock face.

It is important at this point (and not easy to do) to get the tire as evenly "centered" as possible. Then I placed the ring on the outside of the bead and started, finger tight, all the bolts in a "criss-cross" pattern. Through out the torquing down process I followed this pattern. There are 20 bolts and the sequence I used was 1-11-6-16-2-12-7-17-3-13-8-18-4-14-9-19-5-15-10-20.

Once they were all started I first torqued them to 5 ft. lbs. Then 10 ft. lbs and finally 15 ft. lbs. Because you are squishing rubber the first bolts in the torquing sequence will no longer be at their torque setting as you complete a sequence. It is necessary to keep repeating the final 15 ft. lb. sequence a number of additional times in order that all the bolts end up equally at 15 ft. lbs.

Because I had recently moved my compressor and have not yet run 220v to its new location, I had to run the rims up to the corner gas station in order to put some air in them. At this time, I only had enough quarters to fill the 4 of them to 20 psi each. I am told that it is a good practice, after an initial bit of use, to air them down and re torque them.
DavidGB

[DavidGB]

Thanks Gordon!
DavidGB

[W_A_Watson_II]

Great looking! Keep us posted on how well they perform.

[DavidGB]

XML's on Bead Locks

Will,
Thank you for being the one that I learned about Marsh from and with all the help here on the Power Wagon Advertiser Forums in the discussion about rims etc.
DavidGB

[Tanner]

Wheels & tires look great, David! How bad did Marsh abuse the wallet?

And were they adamant about their rims being for off-road use only?

Bryan

[Desoto61]

Very agressive looking. How are they for clearance when turning? Looks like they built the extr width onto the outside of the rim.

I'm probably going to have new rims made up for mine too, not sure if I'll do the bead locks though, but I do like the look!