Dear Tom and Ray:
It turns out that lead wheel weights are the biggest source of lead in California's waterways. There is a bill that would ban them in favor of safer alternatives, especially stainless steel. My question is, Exactly what do wheel weights do? I know they are used to balance the wheels, but what exactly does that mean?
-- Ang
Ray: Wheel and tire combinations are not born balanced, Ang. In that way, they're like my brother.
Tom: Right. But unlike me, wheels and tires can be balanced fairly easily. When we say "balanced," we mean that the weight of the wheel-tire combination is evenly distributed so the wheel won't wobble.
Ray: When a steel wheel or a rubber tire comes off the assembly line, it doesn't always come out perfectly. Oh, it's close. So close that if you drove on it at speeds up to 30 or 35 mph, it would seem perfect, and you'd never know the difference.
Tom: But once you get up to 40 mph or so, those small imperfections in weight balance will make your car shake like a half-prepared fruit smoothie still whirling around in the blender.
Ray: Why are these products not perfect? The metal or rubber poured into the mold might not be entirely homogeneous -- meaning the materials used might not be blended perfectly. Think about pancake batter and the occasional pocket of flour you come across. It's not that extreme in wheel and tire production, but it doesn't take much of an imperfection to be noticeable at high speeds.
Tom: And rather than perfect the production process of every tire and wheel made on the planet, it's a lot cheaper to balance the tires after the fact with a few cents' worth of lead weights.
Ray: Right. If you were manufacturing wheels for gyroscopes to be used in space lasers, and the future of life on Earth depended on them, then sure, you'd use much more expensive equipment and make the parts come out perfectly. But wheels and tires for cars don't need to rise to that standard.
Tom: But there's absolutely no reason why tire dealers and repair shops can't use stainless or "powdered" steel weights instead of lead weights. They work just as well, they don't leach lead into our drinking water and they cost almost the same, maybe a few pennies more.
Ray: A number of states have already banned lead weights, and I suspect the rest, including California, will soon follow. We're all for it.
(Car Talk is a nationally syndicated column by automotive experts (and brothers) Tom and Ray Magliozzi. Write to them at the Car Talk Web site.)
4 Comments
By Dan on February 16, 2010 12:53 AM
Thanks for bringing this item up. One wheel weight coming off of, let's say, one tire in four, for every car on the road, every six months, that is a LOT of toxic lead in the environment. Good question, and great response; great general information to know.
By Jim Morris, Renton, Washington on February 17, 2010 5:24 PM
Toyota’s Recall
The recall of Toyota cars brings back the memory of a similar problem I had with my 2000 Subaru Legacy. After several incidents of having problems stopping and engine racing I contacted Subaru of America. They suggested taking my car immediately to the dealer for a security check. In the mean time I had just read an article in the Seattle Times “Car Talk” in which someone wrote they was having the same problem only it was with a different make automobile. One of Tom and Ray’s suggests was that the driver side floor mat had slipped up under the brake pedal and on top of the throttle lever. After the security check found nothing I started making sure the floor mat was on a peg provided to hold it in place; never had the problem again. Thanks Tom and Ray.
By Jeau Bishop on February 18, 2010 11:27 AM
Why is this even a question. As soon as it was found to be the biggest source of the pollutants and there are options, then do the damn thing.
Done deal! Now get on with it and make it a national law. We dont need anymore pollutants in our waterways than has happily been allowed in the past, when there is such easy answer.
This is why our country can not be a leader when it comes to alternative tranportation. Too much red tape and gawking over problems with easy fixes.
By Brian on February 18, 2010 12:10 PM
Lead is a natural element. It is already "in the environment". Just last year the big cry was that lead shot from shotguns was the greatest source threat to our environment and wildlife. Wh need to focus on the things that take precedence like emmissions and auto accidents which spill hundreds of thousands of gallons of gas and oil onto the ground each year.... Wheel weights..What next? Rubber discarded by the natural wear of the tires on pavement? . :-)