Both wheelcentric and hubcentric fitment is important to proper wheel fitment. When extending the hub, changing the bolt pattern, and installing a different wheel it is absolutely critical to align the wheel to the adaptor to the hub. Vibrations are the enemy when using wheel adaptors and can be very easily avoided by purchasing the proper adaptors.

Here's a scenario: A set of budget adaptors are installed on a 2010 GTI. These adaptors are far from hubcentric. The center bores are oversized beyond 65mm. When bolting the adaptor to the car, care is taken to even tighten the lug bolts in an effort to accurately center the adaptor. Once bolted to the car, the new wheel is slid over the studs and tightened up. The studs should align the wheel, right? The adaptors have no wheelcentric features.

Driving down the road, vibrations are immediately felt. The car is pulled back into the garage and the wheels are removed to inspect. With 8 possible connections off-center, who knows where to start? Care was taken to mount the adaptors properly, so the wheels are carefully re-installed and evenly tightened. Vibrations seem to have calmed down, but are still present. After a few more remove and re-install trips, the car heads home with wheel vibrations that are decided to be dealt with.

Cruising down the highway, the wheel vibrations seem to get worse with speed. Despite being torqued to spec, things are moving around as opposing forces pull the wheel away from the hub and the hub away from the wheel. Soon vibrations get worse, then things get serious. Vibrations have caused the adaptor mounting bolts to loosen. The wheel is now loose, and the driver heads for the shoulder. Luckily, the wheel stayed on and no one was hurt.

The alternative to this scenario is drastically different. Proper wheel and hubcentric adaptors were installed, no vibrations were felt and no issues have been experienced. 42 Draft Designs only manufactures wheel & hubcentric wheel adaptors.
 

Wheel offset, also known as ET, is a measurement of the distance between the mounting surface and the true center of a wheel's width. This measurement can be positive or negative and is described in millimeters. A wheel with an offset of 0 has a mounting surface located along the centerline of the wheel. Wheels with negative offsets have mounting pads closer to the inside of the wheel. Wheels with positive offsets have mounting pads deeper in the wheel, closer to the face. Most modern FWD and AWD cars have wheels with positive offsets ranging from 20-50mm.

Visual Glossary: Offset
Wheel Offset 101
 

The thickness of your adaptor will be dependent on the width and offset of your new wheel. Many other factors play a major role in wheel fitment, including suspension geometry, tire size, and the unique shape of your vehicle. It's impossible to list a fitment chart, so we've put together a step-by-step guide to figuring it out.

Wheel Offset 101
 

Stud size is an option for many of our conversions. In many cases, we've chosen the stud size and length that fits 99% of the wheels available in your bolt pattern. If you have the option of stud size be sure to measure your wheel before ordering. Adaptors that offer a choice of studs fit a true assortment of wheels. The wrong choice may not fit your wheels.

M12x1.5 studs are 12mm in diameter with a 1.5mm thread pitch. M14x1.5 studs are 14mm in diameter with a 1.5mm thread pitch. Thread pitch is not important, we only offer matching lug nuts. Diameter is crucial. The only way to determine the stud size you need is to measure the bolt holes on the back of your new wheels. We recommend using calipers. Measure carefully! The holes may be oversized, but not universal. Choose the stud size closest to your wheel mounting holes without going over. Here's some basics to understand:

M12 studs will fit in a 12-13mm hole. M14 studs will not.

M14 studs will fit in a 14-15mm hole.

M12 studs will fit in a 14mm hole. The lug nuts will work. If given the option, we prefer to match the stud size to the wheel exactly. Safety First.

In some cases M12x1.5 Extended Studs will be available. Extended studs are necessary when your wheel has a thick backpad. Typically, the backpad is 10-15mm thicker than a normal wheel requiring a lug bolt or stud 10-15mm thicker. Given the wide range of wheels used with adaptors, sometimes you won't know you need extended studs until it's too late - unless you measure.

Let's compare an OEM wheel setup to your new wheels. If you drop an OEM lug bolt into your OEM wheel you can measure the distance that the lug bolt protrudes through the mounting pad. OEM lug bolts typically measure 27mm long from the bottom of the seat to the end. A fully threaded lug bolt has 27mm of threads and protrudes 18-20mm. Now drop the same lug bolt into your new wheel. It should protrude 18-20mm. If not, you may need extended studs. Our normal studs protrude 30mm from the adaptor, so you have some wiggle room. If your lug bolt protrudes 13-20mm you do not need extended studs. If your lug bolt protrudes less than 13mm, you need extended studs. Our extended studs are 15-20mm longer.

Visual Glossary: Wheel Stud
Visual Glossary: Digital Calipers
Visual Glossary: M12x1.5
Visual Glossary: M14x1.5
 

Lug nut size is easy. If no stud size choices have been offered, we will force you to choose a lug nut that fits. If you have a choice of stud, be sure to match your lug nut size to the stud size you've chosen: M12x1.5 stud - M12x1.5 Lug Nut for example. If you choose the wrong diameter, we will probably send you the correct diameter based on the studs you selected.

Style is a bit tricky. We offer lug nuts with a choice of ball seat or cone seat. Ball seat lug nuts are typically used with OEM wheels. Cone seat lug nuts are typically used with aftermarket wheels. It's important to choose the correct seat. Before ordering, grab your wheel and feel the lug bolt/nut mounting surface with your eyes closed. If the surface seems to contour to the pad of your finger, you need ball seat. If the mounting surface seems to be a straight taper, you need cone seat. The difference is easily recognizable and documented in our Visual Glossary.

Porsche wheels require a unique type of ball seat lug nut. Compared to a typical OEM VW/Audi ball seat, the Porsche ball seat is much larger in every way. VW/Audi ball seat features a 12mm radius. Porsche features a 13mm radius and a much larger overall diameter. VW/Audi ball seat hardware typically uses a 17mm socket. Porsche uses a 19mm socket. When viewed side-by-side the difference is obvious. If you're using Porsche OEM wheels you MUST choose Porsche Ball Seat Lug Nuts. If you're using an aftermarket Porsche wheel or another wheel with 5x130 bolt pattern you must be absolutely sure before ordering. Check out our Visual Glossary for comparison photos.

No matter what style of lug nut you think you need, double check. Using the wrong style lug nut WILL damage the wheel and may result in your wheel coming loose. Safety First.

Visual Glossary: Lug Nut
Visual Glossary: Cone Seat
Visual Glossary: Ball Seat
Visual Glossary: Porsche Ball Seat
 

Hex head lug bolts are used because of their shallow head and large, flat mating surface. In order to safely mount an adaptor as thin as 15mm, shallow head bolts must be used. If a normal lug bolt was used, the heads of the mounting bolts would interfere with the wheel. Using our hex head lug bolts, 15mm and 18mm adaptors are safe and possible.

Visual Glossary: Hex Head Lug Bolt
 

Given a choice, we prefer short head lug bolts when the thickness of the adaptor allows. Short head lug bolts use a traditional tapered mating surface that allows for better structural integrity as the adaptor increases in thickness. The heads of these lug bolts are designed to be short, allowing the lug to recess into the adaptor.

Visual Glossary: Short Head Lug Bolt
 

Colored anodizing would provide a great finish for our wheel adaptors, but we chose to skip it. Without a local anodizing shop, or even an established relationship with a regional shop, we are unable to offer an anodized finish without significantly delaying turnaround time and increasing price. Given the competitive nature of the essentially custom wheel adaptor market and the time sensitive demands of show season, we have decided to not offer an anodized finish at this time. In the future anodizing may be a possibility.

Anodizing does offer some corrosion protection, which was part of our decision making process. Despite the corrosion protection benefits of anodizing, our decision remains the same. To learn more about corrosion and wheel adaptors, continue on to the next FAQ.
 

The pry slots are shallow pockets machined into the hub side of the adaptor. These pockets are located inline with the mounting bolts where the tightest bond occurs. To remove a stuck adaptor, simply insert a large screwdriver or thin pry bar into the slot and pry the adaptor away from the hub. If the adaptor remains stuck, work in a star pattern attacking each of the mounting holes until the adaptor breaks loose.

Visual Glossary: Pry Slots
 

A centering ring is a ring designed by 42 Draft Designs to be used only with 42 Draft Designs Wheel Adaptors. Centering rings install in the wheel side of our wheel adaptors and fit the exact center bore of the wheel to be installed, allowing true hubcentric and wheelcentric fitment. 42 Draft Designs centering rings cannot be used for any other purpose.

Hubcentric rings are universal rings designed to install in the center bore of a wheel, changing the diameter of the center bore. Hubcentric rings are designed to fit inside wheels - sometimes universal, sometimes specific. Hubcentric rings are typically not necessary with wheelcentric adaptors and only available in common sizes.

Visual Glossary: Centering Ring
Visual Glossary: Hubcentric Ring
Centering Rings Exposed!
 

Wheel center bore can be difficult to accurately measure. Before heading out to measure your wheel center bore, do some extensive research online. Unless you're running a completely unknown wheel, the center bore of your wheel or the vehicle it came from will be published online by someone. If you don't trust the published size, measure your wheel.

Wheel center bore cannot be measured with a ruler. It can't be compared to a print-out from a picture. The easiest and most accurate way to measure wheel center bore is with a dial caliper - digital or analog. Digital calipers are much easier to find these days and will convert Metric and American units with the touch of a button. We like digital.

To accurately measure your wheel center bore, first lay your wheel on a soft surface to avoid scratches. If the center bore has ANY corrosion, clean it with a coarse Scotch-Brite pad. Using the ID jaws of your caliper, measure the center bore at 12 and 6 o'clock. Be sure the jaws are placed equally in the circle and sitting flat against the metal. Wiggle the caliper until the jaws sit flat and you see the largest measurement. Repeat this measurement three more times inside the circle, rotating the wheel 120° each measurement. The largest accurate measurement found will be your center bore. This measurement should match the other three. If in doubt, measure your other wheels to achieve an accurate average.

Visual Glossary: Digital Calipers
Visual Glossary: Center Bore

Installation is simple, however it is very important to follow our installation instructions step-by-step, use the proper tools, and torque all hardware to the recommended specs. Proper adaptor installation is key to a safe and successful wheel conversion.

5x-5x Wheel Adaptor Installation Instructions
4x-5x Wheel Adaptor Installation Instructions