Wheel Rim Size ?

Knowledge base info needed please.....

What is the factory offset or backspace spec of a 6spoke steer wheel on a 77 Road Commander ?

AND how do you measure it........


And is the drive rim the same spec as the steer?
Are these what the yanks call Dayton wheels ?

My web search suggests that 'backspace' and 'offset' are not the same and l have seen obviously different rims on the steer.
Advice appreciated.

Dayton Steel Products is/was a foundry that made truck stuff like turntables .........IH call them cast wheels..............the general idea with a steer wheel is that the axis of the kingpin should be very nearly coincident with the centre line of a rolling tire...........there is usually a small offset of around 1/4 to 1/2" ,which causes a slight drag on the steering components to negate the effect of any clearance that would cause wandering ..................Its highly unlikely that this rule would be deviated from in a production vehicle.........but when someone fits much wider tires this balance is lost,and heavy side loads are put on the kingpin and wheel spindle.

I was anyways under the impression that Dayton wheels were 5 spoke and Malco were 6 spoke according to the yanks.
Who knows.

roKWiz wrote: I was anyways under the impression that Dayton wheels were 5 spoke and Malco were 6 spoke according to the yanks.
Who knows.

McGrath axles are 6 spoke and have Malco cast on the spider and Probar are 5 spoke and have Malco cast on them

So I'm no help here

Paul

Back space is exactly what says, 5he distance from the back of the rim to were it mounts on the hup
Offset is how far from the center of the rim that the rim mounts to the hub

Thats my understanding

Paul

www.moderntiredealer.com/article/312133/...uide-to-wheel-offset

Years gone by yanky trucks here in Aus had same wheel rims all the way round unless ordered differentley ( normally 8.25 " wide as stamped on the rim)
Budd refered to the disc wheel rim with stud holes to suit




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Dayton rims 3,4.,5.,6,.8 spoke wheels (aka ..... Spider , spoke, wobbly wheels} needed a spacer (notmally 4 inch wide) mounterd on spoke to seperate the 2 wheels as a duel
the duels were held on with studs, wheel claps and a nut to keep it all togeter

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It was quite common on British buses to have different offsets front and rear.......the front wheels often had no dish at all.............it wasnt common on trucks tho,because owners would have wanted all wheels to be interchangeable for service reasons.

Here we are in Yankeeland, the cold and frozen northern part thereof, and in this corner of the tire shop we have a pile of Dayton wheels. They have a big round hole in the center and they are made to mount various sizes of tires onto spoke hubs. The hubs may have three, four, five or six spokes. I've seen eights and tens, oddball wheels for oddball trucks. They all have this in common: unless they are properly mounted by a trained and experienced tire person on the spokes ("spider" in Oz) they will wobble. When they wobble the truck dances around as it goes down the road, the lug nuts generally loosen and the wheel often parts company with the hub. This rarely occurs when the rig is parked.

In the next pile we have Budd, or stud piloted wheels. A good many of them are headed for the scrap pile because they are cracked . The cracks start at the stud holes and travel to the next stud hole, to the center hole or to a hand hole (more on this below). This type of wheel is located concentric to the hub by a hemispherical recess at each stud hole which is mated to a hemispherical (not tapered) lug nut or stud nut. The most endearing feature of this setup is the horrendous number of fasteners required to paste the wheels onto the hubs. It's not bad on a single wheel mount as on the steer: there is one stud for each hole (eight on light duty, ten on heavy) and the stud is a big burly thing that fills the hole. You slide the wheel gently on to the studs and run the nuts down snug. Then, unless you have accurate high quality (expensive) torque sticks, you drop the rattle wrench and torque the nuts to at least 375 foot pounds in several stages with the big torque wrench. I never felt comfortable with less than 450. If you just smack 'em on with the air wrench you will learn why there are so many junk wheels in the pile.
Now we turn our attention to the dual wheel sets. Right off you'll see another drawback to this system: the studs are weeny little bits that are just barely big enough to hold up under the required torque. Over tighten them just a bit, they'll snap. Offer up the inner wheel (note that there are, of course, recesses at the stud holes on both sides of the mounting flange, which does a good job of weakening the wheel). Now pick around in the fastener sack and find a stud nut. This dugent has a threaded hole in it with a ball face on one end and a square drive head on the other. It is externally threaded to carry the hex lug nut (also with a ball on one face) that holds the outer wheel in place. Make sure you've got one with the proper thread direction: Budds use right hand fasteners on the left side of the truck and left hand fasteners on the right (or maybe it's the other way around - it's been 45 years since I scrapped the last Budd outa my little fleet). It's a good idea to lube everything - Freylube is best, bar and chain lube works, 90 weight or grease if you've got nothing else. Don't use never seize if you're putting up alloy wheels. I know they don't use much road salt in Oz, but the never seize will jam everything with catalytic corrosion, steel to aluminum. Anyway, run the stud nuts down snug and find your square
impact socket that fits the head. Torque them, bearing in mind that when you break that dinky inner stud you will have to tear the whole damn mess apart and pull the brake drum to replace the bloody thing. Now the outer wheel, more lube, properly threaded hex lug nut, more torque wrench, bear up mate, it's damn near beer thirty.

I'm not gonna get started on what it takes to dismount Budds, it's just too damn discouraging. Move down to the next pile and your troubles are over (well maybe not all over...). The Hub Piloted wheel is the answer to this trucker's prayer - a simple, super strong system that makes tire and wheel work as easy as it's ever going to get. The hell of it is, GMC got this started back in the 30s with the Motor Wheel, but they got into a pissing contest with Budd over an army truck contract just before WWII. GMC were dealing with a bunch of generals who knew vaguely what a truck was, but knew nothing whatsoever about wheels and tires. Budd had older whiskey or younger women or more money or something, so GMC lost out and the rest of us were cursed with Budds for about six decades. (Yeah, military truck construction had that much influence on the civilian market.)

The hub pilot establishes concentricity with four slightly chamfered tangs spaced at 90° around the hub. The tangs are machined such that the wheel is a close slide fit over them. The wheels, whether steel or alloy, have a full thickness of material at the mounting flange. The studs are a close fit in the mounting holes and they are heavy. The nut is made with an integral cone spring lock washer which spins freely on the nut. All this assembly does is hold the wheel on the hub, it worries not at all about centering the wheel. It is good practice to torque down in stages to 500 foot pounds, but I've seen morons slam these things together with an inch air wrench, probably wound 'em to twelve or fourteen hundred pounds, never broke.

Sorry lads, I've done it again, you've got more about truck wheels now than you ever wanted to know... . Just thinking 'bout all that work worked up a thirst, thanks Swishy I'm gonna have a wee sip.

All the best,

Mark

SkipJack M80
Hope eye aint interupt n u're drink n session
LOL
Q:?
the legal requirements to have all tyres fitted with valve (dust) cap
do we haz a
Y or N



cya