Written by: Graham McCrimmon

Competitive tractor pulling has come a long way! From a farmyard contest to fine-tuned competition to see which machine can drag a weighted sled the farthest; it’s a sport where the distance of a pull is measured down to a hundredth of an inch!

Each year the Calgary Stampede Farm Equipment committee showcases our agricultural heritage by bringing together 30 drivers and their restored vintage tractors from Alberta and beyond to participate in the Calgary Stampede Vintage Tractor Pull, celebrating 27 years this year and happening at The Greatest Outdoor Show on Earth Sunday, July 9 – Monday, July 10.

To be eligible to compete, tractors must be built in 1960 or earlier. Participants compete in six weight classes over two pulls to see who can pull a weighted sled the farthest! The sled transfers weight from the back to the front, creating resistance as the tractors pull it forward. Plenty of hours of tweaking, adjusting, modifying and planning go into extracting as much performance as possible, resulting in a winning pull.  The factors that separate a winning pull from the others is: the amount of contact with the ground, the size of wheels, tire air pressure and appropriate weight balance.  Read on to understand why these factors play such an important role in a winning tractor pull.

Drivers want as much contact with the ground as possible to provide more traction. This is achieved by placing their hitch as high off the ground as possible and having the drawbar as narrow as possible, but within the rules.  This puts the hitch at the tractor’s centre of gravity, improving the likelihood of keeping all four wheels grounded.  Maximizing the size of the tire rims is also advantageous (the bigger the better).  Handpicked tires with the most tread allow drivers to dig into the dirt and get the most traction.

Debate remains on air pressure; less air creates more of the tire touching the ground, while increased air pressure keeps the hitch up high.  Champion drivers are able to find the air pressure ‘sweet spot’ for optimal performance for their specific tractor.

Proper weight balancing is not as important, as most tractors are not built to be symmetrical. As tractors forge ahead with their heavy loads, the front wheels will eventually lift off the ground, preventing steering.  Proper weight distribution helps the tractors pull straight without hitting the brakes, which is a big ‘no no’ for a championship pull!

And last but not least, as with anything, practise makes perfect!  Drivers are constantly practising to get their pull precise and ensure that they are pulling slowly to abide by the speed restrictions.

The annual Calgary Stampede Vintage Tractor Pull takes place in the Scotiabank Saddledome July 9 at 7p.m. and July 10 at 6 p.m.  See these passionately restored tractors up close before the big show in Country Trail at the Show & Shines July 9 at 5 p.m. and July 10 at 4 p.m., free with park admission!