Lefties are more perilous than righties

On the other hand touring type motorcycles are more likely to run off the road on right-handers, and there is a huge chance that they will impact while still vertical. Now the reasons for all of the above are undoubtedly still to be fully explored, however I shall give you my personal take on the findings.

Let's start with the sports bikes - let's call them SBs. No-one buys SBs for highway touring; we buy them because they do exciting stuff like cornering really, really well. As we said in the previous missive, in countries like Australia and the UK, the left-hand carriageway of a bend tends to require less speed than the corresponding right-hand carriageway, simply because the radius is smaller and the overall amount of time spent leaning from vertical to negotiate the bend is less. In addition, left-hand bends are easier to perform because they have greater space to set-up and execute, carry less apparent risk and, as a result we like them more.

This means that we tend to carry greater speed and lean angle -- and dare I say it "attack" the corner harder. If we accept that for any bend, depending on the radius and the available friction from the road surface, there is a physical limit to the speed at which it can be negotiated. The closer we get to that limit the greater the risk if something goes wrong. I believe we have a tendency to take left-hand bends at speeds closer to the physical limit than we do right-handers.

We also know from research that most motorcycle crashes occur on clear dry days, usually after lunch. These days it's hard to find the limits of modern sports tyres, as they provide amazing levels of grip in both wet and dry unless something influences the amount of friction -- that something being an environmental factor like gravel, etc, or an action like braking or overloading the front tyre.

It's true to say that many riders apex too soon on left-hand bends and ride "blind" for a period of time, because the distance they can see is much shorter than if they had stayed wide a little longer. Therefore the chances of not seeing a hazard or even misreading the bend are quite high. What do I mean by misreading? Well if you assume the bend is a constant radius and execute accordingly only to find that because you've apexed too soon the bend tightens suddenly, then you have misread the bend.

So, the capabilities of SBs invite us to explore their considerable potential, and left-hand bends reward us with unparalleled excitement. So what happens if something does go wrong - after all I said that the research indicates that most SB crashes are more likely to slide off the road than exit upright.

Let's assume you are approaching a left-hand bend on a road that has a 80km/h speed limit. The advisory speed sign says that the speed for negotiating the bend is 40km/h. We all know that for a motorcycle, advisory speeds are always irrelevant, so we set our speed according to our information. Mid-way through the bend the radius tightens, which demands a much higher angle of lean and tighter turn to negotiate at the speed we have chosen.

Oh, and let's add in a downhill gradient, which is a another significant factor in left-hand crashes.  In some cases the motorcycle can accommodate the increased lean and turn if we have the ability to let it. In other cases it is possible to ride the motorcycle into the ground, where a component such as the sidestand prevents further lean and lifts the tyres off the road surface.

However, most riders will do one of two things: close the throttle to lower the speed into their personal comfort zone, an action that settles more weight onto the tyre and overloads the amount of grip which is already being used up by the tighter turn, the increased lean angle and the downhill gradient; and the other variant is that they try to stand the machine up and apply the front brake at the same time.

In either case, the front tyre loses it precious grip through the contact patch, and the machine which is already leaning over to the left drops to the ground and slides on its side. Once sliding, both rider and motorcycle travel tangentially across the carriageway, through the oncoming carriageway and eventually off the road.

So, in answer to your original question: "Are left-hand bends more less dangerous than right-handers?" If it's okay with you Tom, I'd like to answer that question in the next column, after we've looked at the reasons why I believe touring bikes appear to crash more on right-hand bends.

In the meantime, I'd ask that you simply consider what are only my personal views and apply the logic test. Like all riding advice, it's only any use if it makes sense and you can benefit from it.

Tata for now and ride safely,

Aunty Flo

What do you think? Have you say below.