Apex or Exit - what's important when cornering?
Back in the summer of 2006, I was seduced by a magazine's big cover splash promising "Twenty pages on cornering faster". Despite reading it cover-to-cover, I could only find a couple of pages on cornering technique. The remaining eighteen pages were thinly-veiled adverts for expensive aftermarket accessories or services to get the bike tweaked. Anyway, cynicism aside, the two pages on riding were the valuable content because the best bolt-on accessory on any bike is the rider, and the most cost-effective tweaks we can do are to our own skills. A good rider can still corner well on a wallowing hippo of a machine. But all the bolt-on bling in the world won't turn an incompetent owner into Valentino Rossi or Marc Marquez. It's depth of wisdom, not depth of wallet, that helps us to good cornering out on the road.
So what did the article say? Well the writer spent a lot of time talking about "finding the apex". You may be wondering what the apex of a corner actually is, because it's a word bandied around with some freedom when talking about corners. Think of a triangle - stand it upright - the pointy bit at the top is the apex. Now, connect the three points with a smooth curved line and the point at the top is still the apex. If we now give that curved line some width, so it becomes a road, the apex is where the point of that triangle touches the inside of the corner halfway round.
On a race track, where we can use all of the surface, if we start on the OUTSIDE of the corner and if we also exit on the OUTSIDE of the corner, by just touching the INSIDE of the track halfway through the turn - the apex of the triangle - we take the maximum radius (and thus the fastest) 'racing line' through the corner. So if the corner is a nice symmetrical one, the apex is 'mid-corner', halfway round the bend.
What about 'early' or 'late' apexes, two more terms you're likely to hear in any discussion about riding a track? An early apex comes before we are half-way though the corner, and generally indicates an increasing radius turn - the corner opens out. A late apex comes after we are half-way through the corner and may indicate a decreasing radius turn - a corner that gets progressively tighter. On the track, we learn our lines by going round and round until it all flows nicely. Even on a blind corner on the track, we learn to use marker points (which is why they put cones out on track training sessions) to guide us round.
But the road is not a track, and this 'racing line' which may be the fastest way around the track, is not a great idea on the road where we have to deal with a number of other problems. For starters, we don't get the chance to learn a bend by going round it over and over, and we don't get markers (at least, not handy cones). We have to ride it as we see it, which isn't easy when most of the corners on UK roads are blind - that is, we can't see all the way through them from beginning to end. Aiming for an apex where we cannot see out the other side of the corner isn't a great idea - we could end up turning-in too early, which inevitably leads to running wide later in the corner.
But even when we can see right through the corner, cutting into the apex on a right-hander brings us into close proximity to oncoming vehicles. And on a left-hander, cutting into the apex puts us close to where there might be hidden turnings and driveways on our nearside.
As it happens, the way to learn a track (if the handy cones are absent) is to work backwards. We start by finding the direction we want to be headed on the way out of a bend - the 'exit'. Keith Code's definition of the exit is a good one to work with - it's where we can put the power on as hard as we like. Once we know where we want to be pointed at the exit, then we can find the line backwards to the 'apex', and from there back to the 'turn-in' point where we would cut across the track to clip the apex, and ultimately back from the turn-in point back to the 'entry' which is where the corner forces us to steer or run off the track.
On the road, as I explain in the articles on 'Point and Squirt', the solution is to delay turning-in to the corner to the point where we can clearly see through the exit and where the road goes BEYOND the end of the corner. So if - as is likely - our view around the corner is obscured, we simply stay on a wide line around the outside of the curve until we CAN see the exit - where we're pointed where we want to go next and can accelerate in a straight line, remember. Only when we reach this point do we decide if we should turn-in tighter, aiming to cut across the lane and exit the corner in as straight a line as possible, and this is the key to corners on the road - staying wide in the turn till we can actually see the exit.
Get this right and we avoid almost all 'running wide in the corner' errors whilst the apex looks after itself - it's not something we need to worry about. In fact, far from being an aid to cornering on the road, the apex is a red herring and even a distraction from focusing on the exit and the mid-corner hazards I mentioned a moment ago. For good cornering on the road, simply ignore any debate about the apex.
Kevin Williams
Survival Skills Rider Training...because it's a jungle out there
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