2015 Lawnmower Demolition Derby Rules

All drivers must wear a helmet, long pants, and closed toe shoes.

The derby mower must be a factory available lawnmower. No homemade frames.

Please put your number on each side of you mower so we can track the winners easily.

Mower decks, all headlights, and any other glass and/or plastics must be removed.

No rear engine lawnmowers are allowed.

The engine must be a factory lawnmower engine such as Briggs & Stratton, Tecumseh, or Onan. Nothing larger than 20 horsepower max. No stacks will be allowed

All mowers must have a factory hood and fenders. The hood has to be either screwed or welded down to the dash panel around the driver’s area. If the hood is originally fiberglass you can make one out of sheet metal only, but is must be the same size as the fiberglass hood.

Mowers must have good brakes with forward and reserve gears at the start of the heat

The gas tank must be secured and have a cap on it. Any gas at all leaking and you will be asked to shut your mower down.

If you use a battery, it must be securely mounted and covered. If a pull start engine is used, the driver will not be permitted to restart the engine during the heat.

All mowers must use lawnmower type wheels. Tractor treads and cut tires will be permitted. Air in tires only! No foam filled or solid tires! No tire chains or dual wheels will be allowed. You may glue or screw tires to the rim.

Leg guards are mandatory ad must be bolted and/or welded from the rear fender to the front of the foot rest or frame. No bigger than 3” diameter reinforcement for the leg guards. They cannot have any open sides and they cannot connect to any other reinforcements. They also have to be smooth and rounded out. No sharp edges!

Frame modifications are allowed to these specifications: No more than 12 inches per side of 2 inch X 2 inch X 18 inch angle iron or 2 inch X 2 inch flat ¼ inch thickness. No further back than 30 inches from front factory frame.

Factory mower front axels. Links/Rods no bigger than 34 inch. No bigger than ¾ inch diameter front spindles.

All transaxles must be stock 100%. Welding of spider gears are permitted.

Metals permitted: Steel, Aluminum, and Chromemolly. Engine bay reinforcing is permitted with these kinds of metals only! The metal must be contained inside of the hood compartment and must follow factory body lines. All reinforcement will be no bigger than 2 inch X 2 inch X ¼ inches. Grill reinforcement will be no bigger than 1/8 inch plate except for up to 4 inch X 4 inch X ½ inches thick for spark plug protector. Engine cage cannot go further back than steering column and cannot exceed further than the forward most point of the original factory hood

Changing of pulleys to increase speed is permitted to a limit within reason. No more than 12 mph max! Speed will be strictly enforced by the tech’s discretion.

Starter and Carb protectors are allowed, but are at tech’s discretion


Front: Must be inside inner most point of tires. No further forward than flush with the engine cage. Tubing only up to 2 inches. Ends have to be smooth and rounded. NO SHARP EDGES!

Rear: Must be inside inner most point of tires. No further rearward than flush with rear tires. Tubing only up to 2 inches. Ends have to be smooth ad rounded. NO SHARP EDGES!

Roll-overs: There will be only one role- over allowed per heat. If the driver rolls over he/she will have 90 seconds to roll back over and re-start.

For safety, if a mower does role over, all drivers must stop and wait until that driver gets his mower up right again.

All ground rules will be gone over in a drivers meeting before the first heat.

All rules are at the tech’s discretion on the day of the event.


Call Ashton Traphagan with any questions: 785-969-3104