The science of going around corners is, if not straightforward, then well-understood; all that stuff about corner radius, G-force, coefficient of friction, lean angle… there’s plenty of maths out there to deal with it. Trouble is, actually going around a corner, especially on two wheels, is more of an art, or we’d all be able to do it equally well. Which, when one spends any amount of time watching footage of Fabian Cancellara, is surely not the case.
Of course, going around corners is something all cyclists (except trackies…) do on every ride, so it’s not exactly an alien concept. It’s just that most of us don’t generally go around them any where near as quickly as we might or even as we would like to be able to. And what’s stopping us? Confidence.
Or maybe not. My first cycling crash (and many more since) involved entering a corner way too fast and finding the wheels slide out from under me. Others, less painfully, have involved entering a corner too fast and, anticipating the slide, heading for and ending up in whatever lay around the outside. Either way, lack of confidence was not the primary issue. But that’s a personal failing. Others may find they lack the confidence to enter a corner fast and exit having concluded they could have gone faster.
If only there was a way to ascertain just how fast is feasible. One such, and surely the most reliable, is to go around the same corner time and again, taking it a little faster each time until the limit of tyre grips is reached and the rider either gets a slide and recovers it or gets a slide and falls off. This is fine on a circuit and explains why it is possible to reach extreme lean angles in a criterium or circuit race.
Out on the road, where each corner is either new or encountered for the first time that day, such aggression is likely to end in the ditch. And yet some riders still safely get around quicker than others. To do so they need, not simple lack of concern for personal safety, but the ability very quickly to gauge available grip, to visualise a line through the bend ahead and to judge how fast the available grip will permit the line to be followed.
Grip, of course, is the key. And it changes from day to day and even from hour to hour, which means it must be appraised anew for each bend. Perhaps the least enjoyable long ride I have ever done was from Llucmajor back to Pollenca across Majorca in a rainstorm. The roads on the island are like wet marble in the rain and, even on long straights, there was a constant sensation of sliding around. Every corner, no matter how gentle, was a terror. But, by going very steadily indeed, all but one of our group got back without falling off.
How, then, is it possible to discern how much grip is available? Let’s assume that the bend in question is to be taken at a speed slower than that along the straight preceding it. The rider will have to slow down and, in doing so, will get a feel for available grip from the tyres under braking. Next comes the moment of turn-in, which itself requires countersteering. At this point it may become clear that the anticipated line is too tight and a wider one must be taken; in any case, grip must be determined before committing to a line.
Experience, of course, plays a big part in assessing grip, but it is possible to speed up the acquisition of experience on various road surfaces by practising, especially with braking. Assessment of line should come quickly to anyone interested in developing it. Look for a wide entry leading to a defined apex with a clear, obstacle-free exit. Bear in mind that a downhill bend on a bicycle will accelerate rider and machine while a flat bend will slow them down and that the line followed through them will differ in detail. But, with practise, it is easy enought to gain an eye for a good (if not the perfect) line.
So, at its most basic, going around a corner quickly and safely involves entering it on a good line at a speed at or just below that permitted by the adhesion between road and tyres. Key to the former is the ability to pick out the entry point, apex and exit line, while key to the latter is the development of a feel for grip at the moment of corner entry, which itself is gleaned from braking prior to the bend. Assuming the amount of grip stays the same up to it and all the way through…