Rob Kinnan
Brand Manager, Mustang Monthly
February 26, 2018

One of the most important and difficult visual aspects of building a car is getting the wheel and tire combination “just right.” The ultimate goal is to get the most rubber under the fenders that you can without the tires and fenders hitting each other. The stance is crucial as well, as those wheels and tires must be sized just right and the suspension oriented so that the whole combination is spot-on cool.

In the past, before multi-piece custom wheels came on the market, you were stuck with what the manufacturers had on the shelf, and the choices were slim. But today, most wheel manufacturers can build you a wheel in whatever diameter, width, and backspacing you want (within reason), so the sky’s the limit. The difficult part now is determining how big you can (and should) go. Determining the proper size wheel and backspacing requires a lot of measuring and some educated guessing, but we’ve just come across a tool that makes it easier and much more accurate.

The Wheel Tek from CCTek is a you-assemble-it tool that actually holds a tire you think might fit, and lets you bolt it to the car’s hub and slide it in and out to see exactly what wheel backspacing you’ll need to run that tire—or if you can go bigger on the tire or should go smaller, and even articulate/cycle the suspension and steering to verify clearances as well. The Wheel Tek tool allows you to simulate a wide range of wheels, allowing you to test-fit many different tire sizes and combinations right on the vehicle. It simulates wheels from 15- to 20-inch diameters and widths up to 15 inches. It’s made of 6061-T6 aluminum and has mounting plates to cover 4-, 5-, and 6-bolt wheel patterns.

With that introduction, here’s how it works:

1. This is the Wheel Tek tool prior to assembly. Not shown is a second hub plate (the big triangular piece) that covers 4- and 6-bolt applications. These pieces are all assembled together for the correct size wheel you think will fit, and you’ll also need a tire that’s close to what you think will fit the car to mount to it.
2. The hub plate has these rows of holes to attach the arm angles to, and can simulate wheels from 15 to 20 inches in diameter. There are adapters that extend the diameter range up to 26 inches. We have our tool set for an 18-inch wheel, as shown.
3. The long “channel” plates are the rim sliders, and they bolt to the arm angles/hub plate like so (all the mounting hardware is included with the tool).
4. These bead clamps bolt to the slider plates to secure the tool to the tire bead.
5. We set the tool up to simulate an 8-inch-wide wheel, as shown here.
6. Fully assembled but without a tire mounted. NOTE: In this photo, the top slider is installed 90 degrees off. D’oh!
7. We used one of the Maxxis P245/40R18 tires from our Week to Wicked ’66 Mustang to check the fit, knowing that it already fits pretty well. The tricky part of mounting the tire to the Wheel Tek tool is that you’ll probably have to install the last set of bead clamps to the sliders after the tire is slid over the tool, since in the case of this particular tire construction we couldn’t stretch it enough to fit over the clamps.
8. Bolt the assembly (with tire mounted of course) onto the car’s hub and secure with the lug nuts. (When using brakes that have removable rotor hats, make sure the hats are in place when mounting the tool, or you must compensate for the thickness when measuring backspacing.) Now you can compress the suspension (it’s easier if you remove the springs so it doesn’t lift the car) to cycle it up and down and turn the wheel from lock to lock, studying how the “checking tire” fits.
9. The sliders are loosened by this bolt (on each one of the three sliders) so you can slide the tire in and out to determine where it fits best. Once you have the perfect fit, tighten the bolts down and remove the tool, then measure the backspace.
10. The face of the hub plate that was bolted against the hub is the same face as the wheel mounting pad, so lay a straightedge across the inner end of one rim slider and measure, and that’s your correct backspacing.
11. The Wheel Tek tool is on the expensive side, so we also tried out this WheelRite tool from Percy’s High Performance that we got from Summit Racing. Made of plastic, it’s more affordable and we’ve seen high-end car builders use one, so it works. But getting the tire profile right with the piece of wire that simulates it is tricky.