Increasing ground clearance for rough road conditions

What's the best way to raise the ground clearance of a car due to bad road conditions.

Photo credit: Pool

What's the best way to raise the ground clearance of a car due to bad road conditions and also what are the pros and cons of using offset rims?

--Harrison N

First, recognise that the difference between belly-scraping and good road clearance is only a few centimetres. You are not trying to change a hippo into a giraffe. If you need a dramatic uplift, start by changing your car.

There are three main ways to give your existing car a bit of a lift. One is to fit higher profile tyres. Check that there is enough room in the wheel arch for that, especially at the front when the steering is on full lock.

Another is to fit longer and stronger springs (the tech specs will depend on what type of suspension system you have – whether coil springs, torsion bars or leaf springs). Torsion bars are the simplest to readjust with no additional parts. Leaf springs might only need different-length shackles. Coil springs will need to be replaced with different specs or (the third option) spacers between the bodywork and their top mounting points.

Bear in mind changing the springs will raise the floorplan but will not increase the clearance of a rigid axle (the type with a differential banjo in the middle) – that will only be raised by changing the tyre profile. A bigger lift than that requires the fitting of much more complex and expensive “portal” axles.

You can widen a vehicle’s “track” (the width between left and right tyres) by using “offset rims” or by fitting a spacer plate between the hub and the wheel. Either method will require careful assessment of the tyre size to ensure there is enough room in the wheel arch and the location shift does not cause rubbing against any other component or restrict the steering lock.

For ordinary motoring, widening the track is primarily a cosmetic change to make the vehicle look more macho-sporty, but will make little discernible difference to the vehicle’s stability. It will improve the lateral weight balance of the vehicle so, for more extreme driving, body roll could be reduced when cornering and keep the tyre footprint flatter, improving grip.

The standard track will be designed to ensure the tyres have space for full up-and-down and turn movement inside the mudguard. Widening might take them partially outside the wheel arch of the bodywork, and the tyre could hit the wheel arch when the suspension is compressed. To allow for that, the wheel arch may need to be cut bigger, and an “eyebrow” extension will be needed to comply with the law which requires wheels to be entirely within the mudguard bodywork.

Whatever you do, do it moderately.


Judging distance from the edge of the road

I recently completed driving school and, despite having a licence, I still find it so difficult to correctly position the car perfectly at the centre of my driving lane. What would you suggest in terms of aligning the car?

--Yousra R

You have already identified something very important – which many people don’t — that will serve you well in your driving career.

Driving lessons, driving tests and driving licences do not produce expert or even accomplished drivers. They produce “authorised” beginners.

Even if these three phases are conducted well and thoroughly (not a conspicuous trend in Kenya) they can deliver little more than “basic competence” – just enough to enable you to drive solo without immediately posing an unreasonable hazard to yourself or other road users. They are a start, not an end product. A “certificate of competence” which earns you a licence is not a job done, it is a job began.

The job thereafter (and forever) is to constantly improve – with purposeful practice – your basic control, your more advanced skills, your experience and judgment in anticipating and assessing situations, etc. Your best chance of achieving that is knowing from the outset that it takes years of focus.

And even after 50 years of expertise, it needs constant review to adjust to your own physical and mental ageing.

You know what you were taught and how you were tested to get your licence. As a perspective, in countries with good teaching and tough testing, learners are expected to have a thorough knowledge of two books - on "theory" and "essential skills". Each book is 400 pages long!

On your specific alignment issue, practice will be your essential tutor. To assist this it might help to put a mark on the leading edge of your car’s bonnet. In a safe place without traffic, park your car about one metre to the right of a visible line at ground level running parallel to the car. Sit in your usual driving position and see where that ground line visually meets the leading edge of your bonnet. Put the mark there, where you can easily see it from the driver’s seat. If, when driving, the edge of the road is to the right of that mark, you are less than one metre from the edge. If it is to the left of your mark, you are more than one metre from the edge.

The exact position on the bonnet will vary according to the shape of the vehicle and the eye level of the driver (short or tall, high seat or low seat).

With this reassurance of where you are aligned in your lane, practice will develop your judgment of where the inside edge of your car is. For those of you chuckling up your sleeve because you have mastered that, test yourself: On a piece of open ground, place a zig-zag pattern of six old tomatoes, about 10 metres apart from each other.

Drive the zig-zag non-stop, and see how many of them you can squash with your left-hand front wheel in one pass. Lewis Hamilton would hit all six.

If you get even one of them, you are doing quite well.