Wheel Fit Tire and Wheel Test Fit Tool WheelWorks Educational Instructions How-to Overview

Wheel Fit Tire and Wheel Test Fit Tool WheelWorks Educational Instructions How-to Overview


Now that you know how to setup your wheel
fit tool on the vehicle and get the proper fitment, this is our educational portion where
we’re going to discuss terminology like backside setting, offset, bolt pattern and other things
that you need to know correctly to be able to build the wheel that you want to fit in
your car. And tell the manufacturer the information
that they need so that everybody gets it all together strike and the two pieces come together
correctly when they bolt on the car. The first thing that we want to start on is
to learn how to measure our backside setting. This is a very critical measurement, of course
you see how we use it on the wheel fit tool. Here’s how it looks on an actual wheel. Take your wheel, place it face-down. Now, you’re going to need a straight edge
of some type that will overhang the back flange of the wheel. We’ve got just a simple piece of wood here
in the shop and I’m going to demonstrate how this is going to work. You let the straight edge overhang the rear
flange and you take your ruler or tape measure and you drop it perpendicular, straight down
to the mounting pad. Now, the distance from the mounting pad to
the bottom of the straight edge is your backside setting. In this case it’s three and three-quarters
of an inch as you can see here on the tape. Okay, so now you know backside setting, now
we’re going to move to offset. Offset is the relationship of the mounting
pad to the center line of the wheel. Using our wheel as a demonstration, the centerline
of the wheel is the exact center of the wheel with half in the front and half in the rear. That is our center line. Now the relationship of that mounting pad
to that centerline in a distance measured in millimeters is our offset. If the mounting pad is toward the street,
that’s positive offset. If the mounting pad is toward the rear of
the wheel, that’s negative offset. In our example here, we’ve got a negative
offset wheel. It’s a 15 by 10 and it has a three and three-quarter
inch backside setting. There is a direct mathematical correlation
between backside setting and offset and we’re going to show it to you here so that you’ll
understand it. In your paper instructions, you’ll see a cheat
sheet that is very useful. It’s a simple chart, backside setting going
in one direction and width going in the other. When the two come together you know exactly
where you’re at between your backside setting and your width and the millimeter offset is
right there in the middle. Now that you understand the difference between
backside setting and offset, let me tell you the calculation to convert between one and
the other. If you take your width in inches and that’s
the measured width from b to b, add one inch. That’s a half-inch for each flange, front
and rear. That’s your overall width. Now divide that in half, that’s your centerline. Now take that number and subtract it from
your backside setting. That number, in inches, multiply it by 25.4
and that will give you your millimeter offset. If it’s a negative number then that’s negative
offset. If it’s a positive number then obviously it’s
positive offset. That’s the relationship between those two
measurements but it’s very critical that you understand because some manufacturers use
one figure, other manufacturers use the other. You need to be able to understand how they
relate to each other. Here’s several diagrams to help you understand
the difference between a reversed offset, a standard offset, a medium offset and then
high positive offset. We’ll take a look at the reversed offset first. That’s where the mounting pad is toward the
very back of the wheel. There it means it will be like a two and a
half or three inch backside setting. Now, then you’ve got a standard offset. Standard offset is where the mounting pad
is in the middle of the wheel. It doesn’t necessarily have to be at zero
offset but maybe plus or minus 12 millimeters one direction or the other. And then you’ve got medium offset which is
typically in your +25 to +30, depending on the width of the wheel. But the mounting pad is forward of center
line but not all the way out towards the front. And then of course you’ve got your high positive
offset where the mounting pads way out toward the front of the wheel. Typically, it’s a flat-face. And this is most common, and you’ll see it
in more modern vehicles whereas typical street rods, muscle cars of the pre-80s era, are
going to have a standard to reversed offset. Just to kind of give you an idea of what you
should expect to see on most or all of your applications. Now let’s talk about some common lug nuts
so you’ll be prepared to bolt the tool to your car correctly and understand what’s out
there in the market. First we have your acorn bulge lug nut, which
typically has a three-quarter hex and has a fat head on it. The other one that you may not be familiar
with but is a great lug nut especially if you have to use a spacer on vehicle for some
reason or another. You know, perhaps you you can’t build the
wheel exactly the way you need or a buddy may have wheels on his car that he can’t buy
the wheels that he needs but he needs to make them fit. Maybe he picked them up at a swap meet. This is called an ET mag lug nut. And if you look right here it’s conical seat
so it fits most of common wheels with a 60 degree taper but it has a little tiny shank
on the end. And what that little shank does is it gives
you an extra five or six turns on the lug nut. So, if you’ve got a small spacer plate on
there, this one lug nut right here will help make up those lost threads by actually going
further down into the lock-hole and giving you more bite and clamping force. The other neat thing about this particular
lug nut is if you know someone with a front-wheel drive vehicle that has a little vibration
in it especially at highway speed, many times this type of a lug nut will help center a
lug centered wheel directly onto the hub of the vehicle. Make it straighter and more centered and hopefully
should eliminate some of the vibration. Here’s some other lug nuts that we have. You may be familiar with mag shank lug nuts. And you’ve got a standard mag lug nut which
is about three quarters of an inch and you also have an extended mag lug nut like this
one right here which is common in your old Cragar SST wheels and some other racing type
applications. It’s got a 1.379 inch shank or somewhere pretty
close to that. The important thing to remember, depending
on what the application is, these lug nuts have to have a washer. Many times the washer is built on to them,
but if you’re working with an old school application such as like a Cragar SS or a Keystone classic,
you’re going to need the additional washers and you’re going to make sure, need to make
sure that you have the correct washers there. Let me show you what I’m talking about. Here’s the Cragar washers. Notice that they are…have a round outside
diameter. One is punched in the middle, one is punched
to the side. Notice on the back that it says wheel side
actually engrained into the washer. You’ll make sure that that faces the wheel. There’s a concave shape to this washer. So so as you torque your lug nut to spec,
this washer applies a little bit of resistance to it and presses against the wheel to hold
it in place. Now the center punched washer is used for
a five on four and three-quarter bolt pattern, whereas the offset washer is used for five
on four and a half and five on five bolt patterns. Now if you have a five on five bolt pattern
it will only fit a half-inch stud. Not the 88 and up trucks with a 14 millimeter
stud, that’s a completely different part number. Now if you’re working with a Keystone Classic,
the washer on it has an oval outside diameter. Again, it uses a center punched and an offset
punched washer to fit the bolt patterns that we mentioned earlier on the Cragar SS. This washer specifically sits down into a
recess that’s actually cast into the wheel. So, make sure whichever one that you’re working
on that you have the correct washer and that you have it placed on the wheel exactly where
it needs to go. Now the next one that we have isn’t that common
on street wide applications, but many times you’ll get a kit like this and you’ll need
to know how to handle it. A number of years ago, what was called a Socket
lug commonly known as a Tuner lug was developed and brought into the market. It works okay, but the problem is it has an
open end. It allows moisture and dirt and debris to
get down there and can typically seize up the lug nut onto the stud. Also the hex head key that comes with these
generally gets worn down fairly quickly and gets to a point where you can’t get proper
torque on the lug nut to make sure that you get the clamping force that you need to maintain
the wheel on the vehicle. If you run across these or someone sends you
these, I highly recommend not installing this particular product, but actually for the SplineDrive. The Spline Lug Nut has a closed end. It looks much like a key and the key that
fits over it is on the exterior which has got plenty of bite, much better application. They make these for smaller diameter. You know 12 millimeter tuner-style applications
as well as normal street rod applications. But they also make some truck versions as
well in the 14 millimeter size. It’s a good application, works very well. Just make sure you remember where the key
is and write down the number of the key. If you lose it many times, you can call the
factory and get a replacement key for just a few dollars. Next we’ve got lug bolts. These are common on European applications. You’ve got the lug bolts with a 60-degree
comical seat which is typical of your BMW but then you’ve got a number of ball seat
applications like this one right here. Notice the length of the bolt is pretty long
on this application. These are designed for specific vehicles and
specific wheels. This bolt that secures an aluminum wheel on
the vehicle, is not necessarily going to be the correct one if you put like a spare tire
wheel on the vehicle which typically has a steel wheel. Also, if you put an aftermarket wheel application
on one of these European vehicles, typically your Mercedes, Audi, BMW, you need to verify
that the bolt that came off the car protrudes through the lug hole the same distance as
the original factory wheel. If it pushes too far through there, it can
actually get into the braking system and cause other damage potentially with the car. So, make sure that the length of this thread
here, the part that sticks out, is identical on the wheel as well as on your after-market
application. One way to overcome this is to install what’s
called a stud conversion, which is a stud by itself that is threaded on both sides. It simply screws into the hub of the vehicle
and allows you to use a standard lug nut on that vehicle. Again, you need to make sure you have the
correct thread sticking out so that you’ve got full lug nut engagement. Now I’m going to talk about a centric ring. This ring essentially takes up the gap difference
between the hub of the vehicle and the center bore of the wheel. It allows the wheel to be placed on the hub
much like a factory wheel, and allows it to be hub centric. It gives you a very good fitment, it helps
to keep the wheel straight while you torque the lug nuts down and can reduce or completely
eliminate vibration. If you’re building a wheel that is custom,
typically they machine the wheel to your specific vehicle. But if you’re taking a wheel out-of-the-box,
typically the center bore is large enough to fit a number of different vehicles that
have the exact same bolt pattern. So, keep that in mind. Central rings can help eliminate that vibration
and center of the wheel properly. Now I’m going to talk about how to measure
the bolt pattern. The 4, 6 & 8 lug bolt patterns are pretty
easy. Take a ruler or measuring tape and measure
from the center of one bolt hole across the centerboard to the center of the bolt hole
opposite. In inches, that will tell you what the diameter
of a circle is that goes through those bolt holes. Now for a 5 lug application, it’s a little
bit different and it’s only approximate. Let me show you how this works. Place your ruler in the middle of one bolt
hole and measure to the very outside edge of the bolt hole directly across the center
bore. Now, because you’re measuring off-center and
not directly across the center bore, you have to compensate slightly. That’s why we go from the center of one bolt
hole to the outside edge of the other one. Now this is useful in trying to determine
if something is…If a wheel or a vehicle is five on four and a half, five on four and
three quarters, five on five. What it is not accurate enough to tell you
is if you’re working with a five on four and a half or a five on 115 millimeter or a five
on a 120 millimeter and a five on four and three quarters, which are only a fraction
of a millimeter difference between the two. But this will help you out if you have to
swap meet or working on a project car and you’re not certain what’s exactly on there. It is accurate enough for that. One other measurement that you’re going to
need to know is called X-Factor or caliper clearance. This is the distance behind the spokes of
the wheel that allow room for your brake caliper. Now, the distance from the mounting pad to
the back of the spoke in inches would be considered your X-factor. What you want to make sure of is that you
have plenty of mounting pad depending on if you have a big brake application, that you
want to convey that information to your wheel manufacturer so that they know exactly where
to build your wheel and how much curvature behind the spoke is going to be required to
clear your brake package. Now you can do this manually with the tape
measure and a ruler and a straight edge, or you can purchase from us an X-Factor gauge
just like these. These are anodized aluminum and they allow
you to simply place the tool up against the hub and it tells you exactly and how many
millimeters is needed to clear that caliper. It’s a great tool. Call us if you’re interested in one of these
and we can get it shipped right out to you All right, there you go. You understand how to set up your tool. You understand how to set up the suspension
and you know all the terminology and dimensions you need on a custom wheel to make sure that
you communicate all the things that you need effectively with the distributor or the manufacturer
of the wheel that you’re going to purchase. Using this information, there’s no reason
at all that you can’t get exactly what you’re looking for. So, push the limit, most time that you can
get correct offset and when you get done make sure you send us the photos of the build process
as well as that finished product. Contact us if you need any help at 251 3776
724. You can email me at [email protected]
and also you can get in touch with me on our Facebook page at facebook.com/wheelworksinc. I appreciate you buying a wheel fit from us
and I look forward to seeing you in that picture. Take it easy.

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