Tech Session at K&T Vintage


Ken Beck, owner of K&T Vintage Sports Cars, center, explains the vintage tire shaving machine to members of the Delaware Valley Jaguar Club, who were visiting the shop for a tech session on the physics of tire and wheel balancing and truing.

The Jaguar’s Purr | December 2011
The Delaware Valley Jaguar Club

By Brian Craig

I’m not a big fan of wire wheels, so the tech session at K&T Vintage Sports Cars on November 12 wasn’t a big attraction to me. But I decided to attend so I could do three of my favorite things: take photos, drive my Jaguar and spend time with good friends from the club. Also, after visiting the K & T Vintage Sports Car website, I thought it would be interesting to view some of their restoration projects in progress. As it turned out it was a productive day and thoroughly enjoyable.

Several of us met at the Holiday Inn just off the Lansdale exit of the Pennsylvania Turnpike. Four Jaguars, two Triumphs, and a Sunbeam Tiger convoyed some back roads to the K & T facility. It was an ideal day for a drive and the roads were marvelous.

DVJC member Bob DeLucia led the way in his TR6 and I played Tail End Charlie. Bob did an excellent job of keeping track of the herd. He only had to pull over three times to keep us all together for the hour long ride. There was a moment of adventure when we all tried staying together on a cloverleaf ramp off Route 22. Whew! We got plenty of admiring stares as the all British car ensemble paraded along the route.


Members of the Delaware Valley Jaguar Club chat and look at the car projects
during a club visit to K&T Vintage Sports Cars

On arrival at K & T we were warmly greeted by other attendees and the staff led by Ken Beck. Approximately 25 members of DVJC and the Triumph Club were present. After taking some time to view the facility and the project vehicles we were directed to a separate building for the presentation. Here we saw some stored vehicles including a magnificent MG TD restoration that appeared better than new. Ken Beck then gathered us in a room for his presentation.

Ken started by giving us a brief history of how he came to be drawn to British sports cars and some of his racing experience. Then he got down to business. What he had to say went way beyond wire wheels. I will try to summarize some of the information with an apology up front for doing an inadequate job. So much excellent information was provided I just couldn’t grasp it all.

Most of the information provided centered on the vibration a driver feels when the wheels are turning. While wheel balance is important it is much more complicated than a couple weights compensating for the imperfections of the wheel and tire. One thing Ken pointed out was some people place all the weights on the inside of the wheel for the sake of appearance. This is the area of the wheel with the most flex and may result in an improperly balanced assembly.

More interesting to me was the fact that older wheels, especially those on British sports cars, are not hub-centered but are lug-centered.

This becomes important when the shop doing a tire replacement uses the cones of the balancing machine to center on the hub opening of the wheel.

Although the wheel and tire come off the machine seemingly balanced, they will vibrate on the car because the wheel wasn’t truly centered when the balancing occurred. K&T has fabricated a number of plates with different lug patterns to properly center the wheel when doing this work.

Ken further explained that their experience has shown much of the vibration is caused by the tire not being perfectly round while in contact with the road surface. This is caused by a number of factors, including imperfections in the manufacture of the tire, wear patterns caused by different drive configurations (all-wheel drive, front-wheel drive, etc.), flat spots resulting from storage, and wear from improper alignment or balancing.

K&T has a machine that shaves surface rubber off the tire to correct this condition. Ken explained their experience has shown that once a wheel is shown to be true and the tire properly seated, this process will solve most vibration problems. The wheel is not balanced until the tire is shaved, as the amount of tire material removed from high spots changes the overall balance of the assembly.

Ken did discuss some aspects of wire wheels, although most of the discussion applied to wheels and tires in general. There were some interesting points made during this discussion.

K&T has been presented with a number of wire wheels people found at auctions, yard sales, garage sales, etc., that seemed to be a good deal. Restoring many of these wheels to a true condition can be expensive as the current labor rate of $75 per hour applies to the repair of the wheel.

Many of these wheels are badly distorted, painted wire wheels tend to have rust at the adjustment nipples and often break while being adjusted, and frequently the replacement of a broken spoke requires the removal of several surrounding spokes so a new one can be threaded in. The chrome spokes are generally less troublesome, as they are made from stainless steel.

Ken estimated there are approximately 500 spoke shapes and sizes with which they have to deal.

So in the end, a bargain wheel may be more costly to repair than the purchase of a new wire wheel. Some of these wheels also present a challenge for their balancing and rubber -shaving equipment as the inside surfaces are not machined and, therefore, do not mount flat against their equipment. They have adapters to correct these problems.

There was also an interesting discussion about inner tube tires.

K&T has experienced several problems with inner tubes being punctured without an obvious cause. Investigation revealed the holes were caused by the inspection label on the inside of the actual tire wearing through the inner tube. These inspection labels are applied through a process that makes them difficult to remove. The most effective method they found was to wire brush the labels off.

Ken showed a photo of the site of a leak on an inner tube where there was a distinguishable pattern. He then displayed the inspection label on the inside of the tire, and the pattern was clearly that of the label.

They have not experienced any inner tube leaks caused by the nipple junctions in the center recess of the wheels. Another interesting tip came here: When they don’t have the protective band for that recess, they use gaffer’s tape to do the job. It is easy to work with, does the job effectively, and does not leave the adhesive residue of duct tape.

The other important point about inner tubes was the size. It is important to have the proper size inner tube for the tire. Inner tubes that are too large result in a fold that eventually wears and causes a leak. Inner tubes are usually sized for several different size tires. Their best advice is to get an inner tube on the smaller end of the recommended size, as it will expand adequately to fill the inside of the tire and will not result in the dreaded fold.

Once this presentation was completed, K&T kindly provided lunch. We then moved over to the main garage to see a demonstration of the tire shaving machine.

One of the cars in the garage was a TR6 with severe vibration problems. The wheels with mounted tires had been removed and the wheels checked to make sure they were undamaged and true. They were found to be in good condition.

Ken placed one of the wheels on the shaving machine and gave it a spin. It was visibly apparent the tire was not perfectly round. The high and low spots could be clearly observed. Also, once the tire stopped spinning the tire always stopped at the same place with a heavy spot at the bottom.

Ken then demonstrated how the machine worked, a relatively simple mechanical process. A template was used to determine the tire contour. The machine was then set to provide that contour during the shaving process.

The cutting blade was set at the center of the tread at the tire’s lowest spot, the tire was set in motion by a motor in the machine, and the tire tread was cut from the center to an outside edge to prevent the blade from chopping up or feathering the tire edge. The blade was again placed in the tire center and cut to the opposite edge of the tire.

This process was repeated several times, taking just a small amount of rubber off the high spots of the tire. Once the procedure was completed the tire was spun freely and it was evident the tire was now uniformly round. It was also evident there had been a transformation in the wheel and tire as it did not seek a particular place to stop spinning. The tire could be stopped at any point and would stay stationary.

Ken was confident that once the other tires underwent the same procedure the vibration problem would be solved. Ken also informed us the balancing takes place after this procedure as the high spots can require 3 to 4 ounces of weights to counterbalance, while a tire having undergone this process usually needs a minor balancing adjustment.

Many thanks to Ken Beck and K&T Vintage Sports Cars for an enlightening and informative tech session. Everyone present learned something. I learned more than most. Appreciation is also extended to Mike Wolf for arranging this tech session, to Bob DeLucia for his leading the caravan, to all the DVJC members who attended as well as our friends from the Triumph Club who helped boost the attendance.

Again, my apologies for the totally inadequate description of this experience. I hate to use a worn-out expression but you had to be there to appreciate it. If you have an opportunity to attend a future tech session please give it serious consideration. Regardless of the topic you are going to come away with valuable information.

Space precludes a description of the cars in the K&T garage being restored, serviced, or stored. To see some of them please feel free to visit my album of photos on the K&T Tech Session.