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Bike of the Month
March 2024
Trackmaster Norton Dirt Tracker
By Charlie Stewart


I was racing a Triumph that had seen better days when Ron Smalley, friend and local Norton dealer, offered to sponsor me if we built a Norton for TT Scrambles. Because of injuries from previous crashes I had lost some of my nerve, but racing was still fun, so I decided to take him up on his offer.


I ordered a Trackmaster frame and Ron supplied the engine, transmission and primary. Some Nortons received water damage on the voyage from Great Britain. So Norton Villiers removed the Combat engine, transmission and primary and sold them to dealers as a package, Norton riders who purchase parts now days will appreciate this, the complete package for $425.


I had quick change wheels, Ceriani forks, plus other parts from the Triumph so work started right away building a race bike. It was not just a bolt up job.


With the frame came aluminum mounting brackets. The engine, transmission and primary would not fit. I phoned Walt Mahoney, who owned Trackmaster at the time, and explained my problem. I was told no two Trackmaster Nortons are assembled the same. He sent a large sheet of aluminum and said when I got mine to work to send him the template. More on this later. I wish that was the only problem.


Much was done to make the engine reliable and also increase the horsepower. Main bearings were updated, parts were lightened and polished, the radii on the crank journals were changed plus other work.


Norton rocker arms have an oil passage inside but not in the same place on every arm. After grinding through to the oil passages on a couple of arms, I took a box of rocker arms to Sacramento to have them x-rayed. The ones with the oil passages toward the center of the arm were chosen to lighten and polish.


Though it was heavier, I wanted to retain the stock Commando 3 row primary instead of going to single row.


Of course the inner and outer primary covers were too long, so an inch was cut from the inner case and welded back together. A homemade aluminum outer cover had to be made. The cover was cut out of an aluminum sheet, a hole was cut for the clutch, and the bottom of an aluminum cooking pan was welded on for the clutch cover.


The transmission had to be mounted rigid, so I used a slipper from a Triumph with a bolt to take up primary chain slack. Ignition was to be constant loss battery, so the end of the crank was cut off where the rotor would mount.


First time I raced the Norton it was leaving a black streak down the entire front straight. I thought this thing had crazy horsepower to lay so much rubber down. Trouble was the streaks were oil and not rubber. It would not scavenge the crank case so it would blow all the oil out the breather. It was a mess!!!


I got really good at taking apart and assembling the engine but could find nothing wrong. After a lot of head scratching, a call was made to  Mr. Slark at Norton Villiers. He said to send him my crank cases and he would check them personally.  My engine cases were returned plus a new set that were modified and ready to be raced. Norton Villiers appreciated anyone racing a Norton and was more than willing to help.


When finished the Norton was light and made good power, was reliable and fun to ride. Thanks to Dave Brant for continuing the sponsorship after Ron sold his business.


Charlie Stewart 4N

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