Riding Skills 101

Cornering Problems 3 - Five tips to understanding cornering dynamics

Why do riders get themselves in a muddle on corners? In my experience as a rider coach offering Survival Skills post-test rider training, much of the problem lies in the lack of training in cornering at basic level. One of the key issues is a lack of understanding of just important it is to get a motorcycle 'set up' well in advance of a corner, particularly when a new rider has a car driving background. Powered two wheelers simply don't work the same way. Whilst the dynamics of cornering are the unique and fun part of riding a bike, they are also the source of many scary moments and crashes.

Why do riders get themselves in a muddle on corners? In my experience as a rider coach offering Survival Skills post-test rider training, much of the problem lies in the lack of training in cornering at basic level. One of the key issues is a lack of understanding of just important it is to get a motorcycle 'set up' well in advance of a corner, particularly when a new rider has a car driving background. Powered two wheelers simply don't work the same way. Whilst the dynamics of cornering are the unique and fun part of riding a bike, they are also the source of many scary moments and crashes.

The key to getting cornering dynamics right is to arrive at the point where we need to steer with the bike settled on the suspension. This means that we need to be travelling at the right speed in the right gear with the brakes released, and with the the suspension balanced thanks to a slight rearward weight transfer that's effected by a gentle application of throttle.

Forget any articles you may have read about how 'bikes turn faster on the brakes'. It's mostly a misunderstanding about what's happening.

Here's the first point to understand - as any powered two wheeler slows, it will automatically turn along a progressively tighter line just so long as the lean angle stays the same. So if we brake into a corner, the bike will spriral into the corner more quickly.

But here's the second. If we go into a corner on the brakes, it affects the steering geometry. Whilst they may look outwardly the same, race bikes and road bikes are set up rather differently. Race bikes - or even a road bike set up for the track - are usually set up to turn on the brakes. The steering head angle is likely to be different, and compared with a road bike where the suspension is designed to absorb bumps, the suspension on a race bike will be very stiff. Track tyres are also a different profile and construction. stiffer. If we brake into a bend on a road bike, with its relatively soft front forks and tyres, the compression of the front end will make the machine sit up in the corner and try to go straight on. If you don't believe me, try applying the front brake mid-corner and see what happens. Better yet, don't try it and just trust me when I say it'll sit up. That's the force we must resist if we turn in to a corner on the brakes. Rather than working with us, the bike is working against us.

We CAN compensate by adding extra steering input, but that pushes us closer to the limit of grip - see the previous article. And in fact, a bike with a standard road set up on road tyres will handle most sweetly with the forks unloaded by a little throttle.

Of course, we need to slow down approaching a bend so the steering dynamics impose a simple rule - we need to get OFF the brakes and back ON the throttle before we begin to change direction.

Sounds easy? Yet we all get it wrong on occasion, so here are five cornering issues we need to think about.

1. Suspension dynamics - to soak up bumps, the front suspension on a road bike is fairly soft but when decelerating (either with a closed throttle or with the brakes) the forks compress. This compromises their ability to soak up the bumps. If we hit bumps in a straight line, this is uncomfortable but relatively relatively unimportant in terms of machine stability unless we are really hard on the front brake, but the bumps will cause the tyre to compress and rebound, which compromises front end grip - it's why the ABS sometimes kicks in when braking hard on a bumpy road. But as soon as we are leaned over, there is a real downside to hitting bumps. Not only does the front tyre lose traction if the suspension's not moving freely, but the more we're leaning, the greater the tendency for the bumps to try to 'kick' the front end sideways. Even with ABS, we'll know all about it if we hit a series of 'stutter bumps' with the forks compressed midway through a bend. The track is relatively smooth. The road isn't.
2. Steering dynamics - if we've finished decelerating (either with a closed throttle or with the brakes) and we're gently back on the power, then the front forks extend again, Now the vast majority of road bikes set up for the road will steer with minimal input from the rider. If we carry brakes INTO the corner, we have to compensate by adding extra steering input which pushes us closer to the limits of stability.
3. KISS and 'keep things simple, stupid' - even when road riders try to avoid braking into the first part of the corner, a common fault is leaving everything a little too late. So we're arriving at the bend and trying to get OFF the brakes, ON the throttle AND steer all at the same moment. Not surprisingly, the timing often goes awry, and the rider enters the corner still playing catch-up. Starting just a few metres earlier, then performing each task in succession - off the brakes THEN on the throttle THEN steer - we only have to perform one task at a time. We're far more likely to complete each stage and turn in to the corner back on the power.
4. A change of mental focus - where do we look on the approach to a bend? Most people will say "at the road ahead" but in fact we'll be looking DOWN at the surface and OUT from the corner towards the point we might run out of road - it's a natural tendency to look where we DON'T want to go. If you don't believe me, analyse your own riding. You might be surprised but it's really not at all instinctive to look around the bend and away from danger. So we should make it a lot easier by ensuring we're comfortable with our approach speed good and early. A planned approach to a corner that sorts our deceleration - and thus our speed - in plenty of time is what frees up our ability to lift our view and look up and around the corner. Why does this work? If we are happy to get back on the throttle, we MUST be sure we will make it round the bend. We're often told we SHOULD look further ahead. This is HOW. It's almost impossible to open the throttle when we're worried we're going to run out of road.
5. Margins for error - last but not least, we simply must have some space to deal with misjudgements. We are performing a complex mental calculation every time we approach a corner - we have to judge the radius of the bend, work out the speed and lean angle that will match that corner, assess where we need to steer to follow the bend... and we can only achieve that if we correctly estimate how much we need to slow down. It's easy to misjudge both our initial braking force and the corner entry speed. By AIMING to get our deceleration finished early, we leave ourselves some extra space in case we find we need to lose a little MORE speed.

All this and more is part of the Survival Skills advanced rider training 'Performance' courses, focusing on better cornering skills. If you're serious about understanding how your brain functions as well as how your machine performs underneath you, why not check them out?

Kevin Williams
Survival Skills Rider Training

...because it's a jungle out there

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