ONTARIO FEDERATION OF 4WD RECREATIONISTS

Hills, (Ascents or Descents) along the trail are likely the most exciting parts of a trail.  However hills can be very dangerous if not handled correctly due to the risk of rolling your vehicle.

DIRECTION OF TRAVEL TO THE HILL

When at all possible the driver shall traverse a hill parallel to the hills vertical rise.    Never travel a hill perpendicular to the vertical rise.

Parallel  Direction of Travel

vehicle descending parallel to the rise of the hill

vehicle descending parallel to the rise of the hill

vehicle ascending perpendicular to the rise of the hill

vehicle ascending perpendicular to the rise of the hill

Perpendicular Direction of Travel

Travelling perpendicular to the hill is not ideal as the vehicles high center of gravity and tire contact points will make it unstable.  In many cases a vehicle can role over in this position.

Vehicle travelling close to perpendicular to the vertical rise

Vehicle travelling close to perpendicular to the vertical rise

 

TRACTION

The number item to focus on is maintaining traction when climbing or descending hills.  learning

  • Use a low gear with your foot off the clutch allowing the engine to do the work for you.  Either the engine will act as a brake when descending or the low gear mechanical advantage will allow you to crawl the hill when ascending
  • proper tire pressure is essential allowing the tire to span out for maximum traction
  • minimize use of the throttle when climbing or descending to reduce wheel slipIf the vehicle looses traction and goes sideways, STOP.  Allow for others to assess the situation and determine a recovery plan

Descent Control

  • Using a low gear allowing the engine to act as brake, if it is a manual transmission your clutch shall be completely engaged. (Foot off the pedal)
  • Tap or use the brake slightly to monitor your descent if required

    Below is an example of how a controlled descent looks on the trail.  Take note that the engine RPM is very low and you can hear the odd brake squeak as the driver taps the brake.

Ascent Control

  • Using a low gear allow the engine to operate at a lower RPM for maximized control , if it is a manual transmission your clutch shall be completely engaged, (Foot off the pedal) or you may need to “ride” the clutch slightly to maintain a slow speed
  • If using an automatic transmission use two feet, one on the brake the other on the throttle to control ascent if required. Using the brake will sometimes trick the differential by stopping a wheel that is spining slightly shifting power to the wheel with more grip

    Below is an example of how a controlled ascent looks on the trail.  Take note that the engine RPM is very low , some wheel slip occurred where as the drive adjusted the throttle and altered the steering to obtain the best line.

When Something Goes Wrong

When descending a hill or obstacle;
If the vehicle is about to role when going down hill steer into the role direction if safe to do so.
Release the brake and possibly give it some throttle to outrun the role and place yourself on flatter ground.
It will be a bumpy and scary ride but it is possible to recover with out causing major damage to the vehicle.

When Ascending a hill or obstacle;
If the vehicle is about to role when going up hill reduce throttle
Place the vehicle in neutral and allow gravity to pull you back down the hill to your previous position

When Experiencing a Roll of the Vehicle

Allow the seat belts to do their job.
Cross your arms over your chest and place your chin against your chest
Clench your teeth so you don’t bite your tongue
Brace for impact and keep yourself in the above position as long as possible
Allow the vehicle to come to a complete stop before moving
Do not attempt to jump out of the vehicle when about to role

Obstacles

An example of an “Obstacle” could be a rock hill like seen above.  Other obstacles could include;

  • Sporadic rocks placed on the trail
  • Fallen Trees
  • Tight areas with off camber positions where body damage could occur

Avoid attempting obstacles (large rocks, fallen trees) head-on. Cross them on an angle with control and in low gear, most obstacles can be completed by “crawling” them.

Never straddle an obstacle, drive your tires over them to avoid being “high centered” (stuck).

Know where the low points are on your vehicle and be aware of their location when negotiating obstacles (usually differential pods on most vehicles).

Use a spotter if you are unsure how to proceed through an obstacle or better yet, get out and check the situation for yourself if it is safe to do so.

 

 

Join OF4WD Today and Get All the Benefits!

JOIN OF4WD TODAY!