We have learned 4WD truths operating scooters, trikes, roller skates, bikes, skateboards. Here are some basics.
• Wheels operate easily in their rolling direction. Attempts to move them sideways may be risky.
• Small diameter wheels drop into holes that big wheels go over. We may topple, electric city scooters do this.
• Wheels get caught in ruts - bike wheels get caught in railway tracks.
• Low tyre pressures make for hard pedalling and higher fuel consumption. Very low pressures may damage sidewalls and wheel rims, cause crashes.
• Riding wiggly -
