What does Offset mean?
Offset is the distance between the hub mounting face at the back of the wheel and the wheel's centraline.
Offset is usually stamped or engraved into the wheel and is measured in millimetres of 'ET' [ET is the short form of the German word 'Einpresstiefe' which literally translates as 'insertion depth']
Positive Offset wheels have their mounting face toward the front face of the wheel. Most front wheel drive vehicles have positive ET wheels.
Zero Offset wheels have their mounting face even with the centerline of the wheel and are by definition "ET 0".
Negative Offset wheels have their mounting face toward the rear of the wheel - powerful rear-wheel drive cars often have wheels with negative offset.
The Pitch Circle Diameter (PCD) is the diameter of the circle which passes through the centre of all the studs, wheel bolts or wheel rim holes.
The easiest way calculate the PCD is as follows:
1) Measure the distance 'S' between two adjacent studs from the centre of each hole.
2) Calculate from the formula below
**Note: on 4 lug fitments you can measure from the center of one stud to the center of the stud directly opposite.
PCD Calculation Formula
4 Stud PCD = S / 0.7071
5 Stud PCD = S / 0.5278
6 Stud PCD = S / 0.5
The 'centerbore' of a wheel is the size of the hole at the back of the wheel which the 'hub' fits into. To help the wheels to seat properly this hole needs to be an exact match to the size of the hub.
Most modern wheels are what's called 'hub-centric' - this means that the hub which protrudes from your car [and mates with the equivalent sized hole at the back of your wheel] is 'load bearing'. All the studs or bolts do therefore is hold the wheel onto the hub!
Some people will say the term 'lug-centric'. They are referring to the use of the lugs to position the wheel on the vehicle in the proper position. If you have' lug-centric' wheels, the state of your studs or bolts is obviously more critical - be sure to replace these from time to time and always 3/4 tighten the wheels off the car to ensure they're centerd. However this is a term that should not really be used with modern day vehicles. Hub centric rings are the correct way to align a wheel properly on the vehicle.
Why are hub-centric rings so important?
As mentioned above these rings keep the wheel aligned on the vehicle hub while your fastening the wheel to vehicle. After the wheel is properly torqued the hub-centric ring does NOTHING! The ring is only used at the time of fastening.
Does the hub-centric ring material matter?
The answer here is NOT REALLY. Again these rings only are needed while fastening the wheel to the vehicle. While some people may think that metal is better because its stronger, there is no need for a strong ring because its not a structural piece. Additionally metal rings tend to corrode and can make it difficult to remove the wheel or the hub-centric ring from the vehicle.
The argument has also been made that plastic rings melt. Well while at some point this may be true, we have witnessed the use of race vehicles using them on track for multiple seasons without ever running into this melting problem.
Plus-Sizing or Up-Stepping are two terms given to the practice of increasing the diameter of your wheels while simultaneously reducing the profile of your tires to keep the overall rolling diameter the same. Benefits - Plus-Sizing will improve the handling of your car! - each step will reduce the proportion of flexible tire 'sidewall' to rigid alloy. This will improve response, will help keep the tire tread square to the road and will improve your car's 'feedback'. If done properly speedo and odometer accuracy will be retained and the car's sure to look better (note: properly refers to maintaining the vehicles stock overall rolling diameter). Disadvantages - In the majority of situations, tire inches are lighter than wheel inches. Plus-sizing can make your overall wheel/tire package heavier. Reducing the profile of your tyres will also reduce your car's damping deflection under compression [the ride quality will get worse]. Other disadvantages can include you needing more expensive tyres, your brakes looking puny. One more important thing to think about whenever you change the tire or wheel size. Consider your environment and the area your usually drive on. If you drive in areas where the road surface tends to be rough (i.e. non paved roads or pot hole invested streets) you may want to consider leaving a decent amount of tire. The more tire and cushion the less wheel bends you may encounter. Sometimes choosing a wheel is more then just what looks best.
All wheels should be installed using a torque wrench. This ensures that the wheels are not too tight or too loose. Check your vehicle's manual for correct settings. When you install wheels for the first time, you should re-torque the wheels after about 60 to 90 miles. Always refer to Owner's Manual for proper factory specifications that take precedence over the listed recommendations.
Here are some basic starting numbers you can follow: 12mm = 70-80 ft. lbs, 7/16" = 55-65ft. lbs, 1/2" = 75-85ft. lbs, 14mm = 85-95ft. lbs, 9/16" = 95-115ft. lbs, 5/8" =135-145ft. lbs.
This torque should be applied in the correct pattern for the amount of studs of that particular vehicle.
Wheel installation hardware, accessories and installation kits are not something that come with wheels. Those items should be ordered with / or supplied by your installer or retailer. There are so many different vehicles with many different factors. Things like different stud length, stud size, thread pitch, hub size, etc.
That is why those items can only be supplied at the point you’re able to inform your installer or retailer what vehicle you have. With this said, here are some basic things to keep in mind during your installation planning process.
1. All of our wheels are conical seat. Its very important to ensure whatever lug nut / lug bolt you’re using is conical “cone” seat. Improper selection of installation hardware could result in a wheel coming lose from the vehicle and causing damage, injury or worse.
2. While there are many different types of lug nuts / lug bolts, when available, we highly recommend using a tuner diameter, spline drive, conical seat lug nut / bolt. Especially if the wheel is tuner drilled or is going to be used primarily for a street application. These offer a small step of security (because they require a key) and they are also narrower and come with an adapter key. That key will help to ensure you can remove and install the lug nuts easier without scratching the lug holes of the wheel. Whatever hardware you decide to run, always ensure it is the correct hardware for your vehicle, our wheel, and your intended use.
3. We always recommend using hub-centric rings. Hub-centric rings are used as an alignment tool so when tightened the wheel is perfectly hub-centric to the vehicle going down the road. In some very few cases, such as many BMW wheels, we have made the wheel hub-centric. However this is something that should always be confirmed by your installer or with your retailer at the time of purchase.
4. *** This is super important! *** Always make sure whoever is installing your wheels completes a test fit of your wheels on the vehicle before mounting. This is a common practice amongst wheel and tire professionals, however it’s incredibly important! It can catch any mistakes in shipping, ensure brake caliper and vehicle clearance, and ensure the wheel is able to sit flat to the hub of the vehicle before install. This is also a great time to ensure you have the correct mounting / installation hardware to help ensure a smooth installation.
We always recommend having your wheels and tires installed by a qualified wheel and tire professional.
One of the most asked questions is what is the best way to care or clean a wheel. The answer is far less complicated then most would think. The answer is soap and warm water. The use of chemical cleaners often cause damage to the clear coat which is used on the wheels. This can result in pealing, flaking or burn spots. The use of special cleaners and wheels soaps should be viewed very carefully. Any soap, or cleaner that you put on your wheel may contain chemicals or some type of acidity to help remove dirt. This is why we only recommend a "safe" vehicle soap and warm water for wheel cleaning.
The best care for any wheel is to clean them often so that brake dust and other contaminants do not remain on the wheel for too long. Things like Brake dust overtime actually becomes acidic and corrosive itself. Others who experience winter weather driving, should be proactive in cleaning "road salt" off their wheels during the winter also. These chemical that they place on the roads to aid in snow melting and tire traction, "salt", can be a few different chemicals. In either case it should be cleaned off your cars paint and wheels regularly during the winter to maintain a safe and proper finish. The best way to care for a wheel is to think of it like an extension of your vehicles paint. If you wouldn't put it on your paint you shouldn't put it on your wheel.
Flow forming technology is one of the most advanced manufacturing technologies to enter the wheel industry. Flow Forming Technology involves the application of pressure to the inner barrel of the wheel, while spinning and after it has been casted. This process stretches and compresses the aluminum, which increases tensile strength. In this respect the process shares similar properties to those found in the forging process. The final product is lighter, stronger, has increased elongation, and a much greater shock resistance as well as the ability to increase load capacity over a traditional cast wheel (of the same design).
Flow Forming Technology has a great number of benefits. Konig has been producing Flow Formed wheels since 2010 and is always improving on the process and efficiency to improve the end product. Below are some visual charts for you to see the drastic benefits as it relates to elongation and tensile strength vs a regular cast wheel. The numbers used are approximate and only for general comparison. These are based off of wheels similar in styling, size, width and other specification. One wheel was a conventional cast constructed wheel and the other is developed using Flow Forming Technology.
What is Elongation?
Elongation is essentially the amount of flex that an object can have before it would reach a breaking point. So you might be asking why would it be more beneficial that a Flow Formed Wheel can flex more before it could ever reach that point? Well, its important when we talk about wheels that everyone should acknowledge that wheels are metal not magic.
While that may be a humorous line its incredibly true. We only build wheels to the highest quality. Konig places every wheel design through a very strict testing standard and build each design to load ratings which are in excess of what is needed for that design’s target vehicles. However, any wheel, regardless of whether it’s an aftermarket wheel or the original factory wheel, has a breaking point. Severe impact and the stress impacts over time can push the metal to a breaking point.
So, let’s get back to the benefit that we started talking about earlier. If a wheel safely has the ability to flex more before ever reaching a breaking point that will increase reliability and longevity of a wheel. This is a benefit to racers on the track as well as the road hazards of everyday use on the street.