BUYING NEW WHEELS? FOLLOW THESE TIPS,
Hub-centric rings are a necessity on most rims
Many forget to order a side of rings with their wheels
One of the fastest growing automotive accessory market segments is wheels. And why not. Styled aluminum or alloy rims can instantly turn a ho-hum mass-produced vehicle into something with a very individualized wow factor. Add larger tires or ones with more aggressive treads and you’ve got something you’ll never have trouble finding in the mall parking lot. Most automakers recognize the potential in this market and now offer styled alloy wheels on many lowerpriced vehicles along with large selections of competitively priced accessory rims. But many drivers look to the aftermarket for new “shoes” for their favourite ride and often just as many forget to order a side of rings with their wheels, leading to a host of problems.
Hub-rings or more accurately hub-centric rings are a real necessity for most aftermarket rims or wheels. The majority of these rims are not machined to match the point on a vehicle’s wheel-hub where the wheel’s centre hole inner surface con- tacts it. This very narrow area on your car or truck might not look like much but it supports the entire weight of the vehicle on the wheel rim. Wheel studs are not designed to do this and they are also not designed to centre the rim on the wheel hub which is essential to smooth vibration-free driving. Hub rings are available in an almost endless variety of sizes in 0.10 mm increments. The inside surface of the ring is sized to be an exact match to your vehicle’s wheel hub and the outer diameter is sized to match the inner measurement of the rim’s centre hole.
Even if you’re dealing with an experienced and competent retailer, there can be difficulties in getting the right rings. While just about every wheel manufacturer knows and publishes the inner diameter of their products’ centre holes, few if any carmakers offer the same listings on the outer diameter of their wheel hubs. In order to get this measurement someone has to remove a wheel from the auto and take a sizing with an accurate caliper device. Once you know the specs and have decided on the wheel of your dreams, buy an extra set or two of the hub rings. They’re relatively inexpensive (usually less than $20 for a set of four) and will come in handy when one gets misplaced or broken. If you have the choice of an aluminum hub ring and opt for it, make sure an application of heatproof grease is applied to the vehicle’s hub before mounting the ring. Almost all auto wheel hubs are steel and an aluminum ring can quickly fuse to the hub after a short time of driving.
The second area of concern with aftermarket rims is the wheel’s offset. This refers to the position of the wheel’s bolt plate (where the wheel studs go through) in relation to the centre line of the wheel. If you look at almost any wheel, the bolt plate isn’t centered but is “offset” to either the inside or outside of the wheel (usually the outside). If the rim doesn’t have the correct offset it can create a hazardous steering problem as well as causing the tire to rub on the inner fender during turns. The solution is spacer plates which can correct the offset. Because spacer plates are usually made of metal and considerably larger, they’re less likely to break or get lost, so you should only need one set.
With today’s vehicles run- ning multiple computers, there’s a new problem; matching the overall circumference between the original wheel/tire assembly and the new selection. Various computers on vehicles monitor wheel speed for such things as transmission/transfer case shift control, anti-lock brakes, vehicle stability control, cruise control, collision mitigation systems and so on. If you choose too large or small a tire, you may end up with a host of warning lights on your dash on the way home from the tire shop or even worse; a vehicle that won’t run at all.
The answer may be a calibration module. The small electronic modules plug into a vehicle’s diagnostic port under the dash. They can be configured to convert the wheel speed signal from larger tires into one that will be accepted by on-board computers. The average price is around $200.