The Lost Art of Tire Shaving

Nov 19, 2023

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Tire shaving, or truing, is something that you don't hear much about these days, and it's increasingly difficult to find any tire shops that even know what it is, let alone how to do it. Yet, with many hot-rodders opting for bias-ply tires, and just as many people going racing, it's more essential than ever. Few bias-ply tires are perfectly round or well-balanced, and if you want your traditional hot rod or race car to perform as well as it can and should, it pays to shave and balance them. The same is true for truck tires fitted to duallies and recreational vehicles.

When I worked at the SO-CAL Speed Shop, we used to take our roadsters to Caldwell Tire on the famed Colorado Boulevard in Pasadena, California, where they had a mobile Amermac shaver that could cut the tires right on the car, saving the hassle of removing the wheels and tires. Sadly, Caldwell is long gone. The only place I could find in the Los Angeles area that still performs this service is Nate Jones Tires in Signal Hill, California. John Beck at Vintage Hot Rod Design & Fabrication in Chico, California, also offers the service, and I'm sure there are a few others across the country. The reason Beck does it is because he and Dave Davidson are land speed racers, and they know the importance of round and well-balanced tires—Dave drives the 300+ mph No. 911 '34 Ford Roadster, and John builds the engines, in addition to driving his own blown, 140-mph Model A Tudor with bias-ply Firestones.

"Typical land speed tires don't have enough meat to shave, but we have shaved a lot of the Dunlop tires that racers use. I fitted new bias-ply Firestone tires to my hot rod, and it just bounced down the highway until I shaved and balanced them. Then it was good for 140 mph," John says.

Vintage Hot Rod uses vintage equipment made by Amermac, a company that is no longer in business. However, I did find that Tire Service International has taken on the U.S. manufacturing of what they call "tire truing" equipment, along with other specialty tire shop equipment. A portable truer, developed from the old Amermac line, costs about $9,000, and their fixed truers start at $10,000.

Down at Nate's, Nate Jr. was about to shave and balance the rear slicks for the mid-50s Bell X-322 Tudor sedan now owned by Brian Mackey's Hot Rods of Huntington Beach, California. Built in 1954 by Gene and Kenny Berglund and raced for decades, it was perfect for my story as the rear "pie-crust" slicks are actually recapped "snow & mud" tires, and, being recaps, were far from round.

"If you're serious about racing," said Nate Jr., "it's important that your tires perform at the optimum. Therefore, making them round, making sure they have matched circumferences (roll-out) and are well balanced is paramount. If you want to win, that is."

When I arrived, the Firestone 5.00 x 16 fronts had already been shaved and balanced. You can see here where the shaving has taken place. The chrome steel slot rims of the Bell X-322 are hub-centric, which means that they are located directly off the flange of the brake drum, so Nate used a special adapter for the tire shaver. Nate Jr. installed the hub onto a shaft that was inserted into the wheel, which will rotate on that shaft.

Once installed and brought up to speed, Nate Jr. wound in the cutting tool. The blade needs sharpening every so often. The blade is moved across the tire by hand, and the smoother the hand, the closer the shave. It can take quite some work to make them round.

A close-up of the cut surface shows the tiny hills and valleys left by the cutting tool. You can see how out-of-round the tire is by comparing the uncut section on the left to the cut section of the right. Also worth noting: Most racing tires will have tread-depth holes, which are a quick reference for tread depth. A new tire should have about 4/32 of tread depth.

With the wheel and tire assembly installed on the balancing machine, Nate Jr. checked the balance. Typically, these old wheels and tires need plenty of weight. Because the owners wanted to retain the clean look of an un-weighted wheel, all the weights were applied out of sight, on the inside of the rim. Wheel weights used to be primarily made of lead, but due to environmental concerns, they are mostly made of zinc these days. In this case, they are the stick-on variety. Once the weights were positioned correctly and stuck down firmly, Nate Jr. secured them with thin, shiny aluminum foil tape that is used mainly for duct work. It also helps disguise the weights when viewed through the windows in the wheels.

This is the only view many racers have seen of the X-322. The car was originally built in 1954 by Gene and Kenny Berglund of Littlerock, California, and was raced extensively at local tracks in the state, from Bakersfield to Santa Maria. The X-322 has had a string of owners of the years before landing in the hands of Brian Mackey. Here it is seen on the track at the RPM Barona Drags.

To kick off the YouTube video series, hosts Kevin Tetz and John McGann immerse themselves in the task of swapping a Gen 3 Hemi into a 1972 Dodge Challenger. And this isn't just any old Hemi—we're dropping a 707-horsepower Hellcat into the car and putting one of Tremec's brand-new TKX five-speed transmissions behind it. The Challenger is also getting a brand new coilover suspension and a brake upgrade. The goal is to make it run and drive like a new Hellcat-powered Challenger, but with the classy good looks of the original E-Body. After you'd done with episode 1, watch EPISODE 2 and EPISODE 3, then sign up to the MotorTrend YouTube channel for more great automotive content!