Perfect Backspacing?

[s1036s]

Has anyone decided what the perfect backspacing would be for the m35a2. I will be ordering custom one piece rims, and can get any backspace. I will probably be doing a 20X11 on 395 tires.
I dont care if hubs are flipped or not...
What do you guys think looks best, since the bed sticks out a lot further then the front fenders.

I know many have done the hemtt rims etc, and based off of those measurements, would you have liked to bring the tire in or out?
Thanks

 

[srodocker]

I think you would base it off the front wheels as you dont want those things rubbing. i have a slight chunk missing out of my front left. need to get a cure for that...

 

[doghead]

Be aware that when mounting the tires(military) on one piece rims, often the bead of the tire is so large/strong/inflexible, that you will bend your rim before the bead goes over the rim bead. Some people install "rim guard" rings in the rims to help with this, but I hear it's a real son of a gun, to get them on.

What tires are you going to use?

 

[ODdave]

A "perfect" back space would be one that centers the load on the wheel bearings....

Sorry, I know this isn't helpful

 

[s1036s]

395s and when I brought the wheel bending issue up to Longs Wheels, they said that they have not even heard of that. So you never know what to believe anymore. A guy posted awhile back about his one piece rims and havent heard if he had any issues mounting the tires.

 

[gringeltaube]

Bending rims??... I've built many wheels using rim shells from Longs (GKN W11-20, 5.7 - 6mm wall thickness, see first drawing); mounted 14.5s AND 395s on them.... I can asure they won't bend even if you used tire irons! (don't underestimate the power of a good lubricant - tire mounting, I mean....)

..."perfect" backspace? Leave everything stock...!

Regaining some lateral stability (taller tires do raise the CG!) via wider wheels and also reducing backspace is always a compromise: the truck may handle (and look) better and the front tires may not longer rub against draglink or J-pipe. But they will stick out from under the fenders throwing mud all over and bearings, steering components, etc. will wear faster!

I have seen some here running on large super single tires/ wheels with backspace = 6 inches or less...!!!!
For a 20x11" wheel like Longs is offering, placing the center disc like shown in my second drawing below, gives you more options without going to extremes. With a backspace of 8.3" - 8.5" and lug holes chamfered on both sides one can use them with rear hubs flipped or not.

Third drawing shows a 395 XML mounted on such a wheel, on the front hub. It will protrude from the front fender about 2 inches (might want to add fender extension lips...), while on the rear there still are 3 inches left from outer tire sidewall to outer edge of cargo bed.


G.

 

[Sevin7]

I know that it has been said before but, Gringeltaube, your posts and diagrams are the best! When is your book coming out because I would like to purchase one. Thanks again!

 

[gringeltaube]

................When is your book coming out because I would like to purchase one. Thanks again!

LOL... thanks for your interest and compliments but....

..... I'm afraid you are the only potential buyer....: who would want to buy what would be such a wild compilation of so many different technical aspects of our toys .... IF WE HAVE THIS WONDERFUL STEELSOLDIERS FORUM, for FREE!!!????
Thank God and the admins we already have our own very complete library, only, searching through the tables of contents and indexes of the many "books" here may be a bit confusing and can be frustrating at times...


BTW: if anyone wants to have any of these drawings in original size (bmp format) just say so.


G.

 

[gimpyrobb]

So now I have a question. The last diagram you have, shows 8.3" of back spacing for a 20x11 rim. If you were to use a rim with 10" width, would you keep the 8.3", go 7.3", or make it 7.8"?

 

[Tinwoodsman]

I want a copy of your book too G. But, only if you autograph it.

 

[gringeltaube]

So now I have a question. The last diagram you have, shows 8.3" of back spacing for a 20x11 rim. If you were to use a rim with 10" width, would you keep the 8.3", go 7.3", or make it 7.8"?

That depends on the wheel lip design of the choosen wheel. Say it was a HEMMT wheel; they are nominal 10" but rim width overall is 12.88", while the 20x11" rims in Q. only are 12.26" WOA. So in order to keep them "reversible" as well, backspace needs to be more like 8.7" in this case. It is clear that that way the tire itself would remain in the same spot relative to the fender, as shown in drawing #3.

Drawing #1 below, gives the dimensions for such a reversible, 6 on 8.75" re-centered HEMTT wheel, for front/ rear tires "perfectly" tracking equally.

Drawing #2 shows what I did with some of these "surplus-super-wheels", recentered using stock A2 centers, welded in. Note that the backspace was increased 1" here, on purpose, since they are intended to be used on rear hubs flipped, only and I didn't want them sticking out that much. (Many pics of the whole process available if interested....)


G.

 

[gimpyrobb]

So your saying that you found some surplus 20x11 "cans" and put stock rim centers in them? I think that would be an interesting thread. Lock ring or solid?

 

[gringeltaube]

So your saying that you found some surplus 20x11 "cans" and put stock rim centers in them? I think that would be an interesting thread. Lock ring or solid?

No, we are now talking about 20x10" wheels and suggested backspace, as you had asked....

I'm saying that I took some of these 150 pound, heavy duty HEMTT wheels (aren't they considered surplus...?) and recentered them to dims. shown in that second drawing, to run 15.5s on a Deuce.


G.

 

[jesusgatos]

That looks GREAT gringeltaube!

 

[JJensen]

I just mounted 395 MVT's on Long's wheels. For me, and my tire guy, it was a PIA. I'm sure others have done it easier. This tire guy primarily does large truck and tractor tires. He said that these were the hardest that he had ever done. It took both of us and another guy to get them mounted. Over 2 hours to mount 4 tires. I got the backspacing that CJ recommended. You can run them on the back without flipping the hubs. That is how I have them on there for now. I'll be flipping the hubs in the next few weeks, and then I'll just turn the wheel around.

 

[s1036s]

Who is CJ? Someone at Longs?
What did the backspacing end up being then? Also can you post pics

 

[JJensen]

CJ is the guy to talk to at Longs. I'm not sure on the backspacing. They are the same as what ODIron's wheels were when he was having them built. CJ will know what it is. I can post pics later tonight. I copied someone else on here. I had holes drilled around the circumference of the wheel to put bolts through. Basically to have a simulated HEMMT wheel. I like the look. Appears more rugged and military like. I didn't want a fancy look on the truck.

 

[gringeltaube]

.................. I'm not sure on the backspacing. They are the same as what ODIron's wheels were when he was having them built. CJ will know what it is............

Yes, he will know for sure!

Also, from my very first concept drawings on (which I found out later, "someone" - not me - had edited, (obviously for his own interest!), probably to hide some of the dimensions shown, .......... see: http://www.steelsoldiers.com/general-polls/10580-m35-wheels-3.html#post101158 , also post# 28....... and compare with the original drawing, 1st pic below....

...... it should be 86-87mm (3.44") FRONTSPACE and 212-213mm(8.33") BACKSPACE, if you want them to be perfectly reversible when flipping the rear hubs.

See it here again: no matter if the rear hub was flipped or not, the wheel/tire will remain in exactly the same position and also tracking exactly the same as the fronts, of course.... (2nd drawing)


G.

 

[JJensen]

I just looked at my notes. The front side offset is 3.5" on my wheels.

 

[gringeltaube]

That's fine!

BTW: from my own (short) experience I know it is very difficult to build them to run perfectly true... within 1/16 of an inch, or say 1.5mm max. runout, measured where the bead seats.
Have you ever checked lateral runout on yours?

G.