Antique car accessory: The rise and fall of grounding straps

Twenty years ago, rubber straps under the rear bumper were standard equipment for most cars. Today, they are a rarity on our roads, although it is interesting to note that they can still be purchased in some automotive stores.

Although many old solutions have become history, some still have their advantages. You can certainly do without bead seat covers, but antistatic rubber straps—also known as grounding straps—have an essential function. These straps, reaching from the bumper to the pavement, were once an inseparable part of every vehicle. Today, they are mainly found in older car models.

Why were these straps so important? Their primary function was to eliminate the so-called shock effect, the unpleasant feeling of a spark when touching the vehicle's body after exiting it. When we felt the body after closing the doors, a spark would often appear due to the buildup of electric charge.

The source of this problem was the electric charge accumulated on the car’s surface. This charge could not be freely discharged because the car's metal parts had no contact with the ground. This phenomenon was particularly noticeable in winter when the air was dry. The antistatic rubber strap was designed to remove these charges.

What was the problem with this solution? It didn’t work fully effectively. Although the straps discharged electricity from the body, the driver's and passengers' clothes would also get electrified during driving. Even if the electricity was removed from the vehicle’s body, one could still feel this unpleasant sensation after leaving the car.

Although antistatic rubber straps have practically disappeared from passenger car equipment, they remain mandatory for tankers. Their role, however, is not limited to eliminating the shock effect but primarily prevents sparks during fuel transfer, which could lead to severe consequences.