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Tightening bend – slow down or lean over more? Part 2

Ken Haylock’s been back with another long reply to my reply to his original reponse to my IAM book review.

I made our conversation a separate post here on the blog because I felt he made important points, and likewise, rather than hide this next reply and my further response away in the comments, I think like the original it’s worth making the discussion a post of its own. I’ve done just a little cutting and pasting to try to make the to-and-fro nature of the discussion a little more coherent.

I’m aware that reading an “I said, he said…” type of conversation gets complicated (as well as a little dull!) to read but if it’s a topic that interests you I think it’s worth persevering as I believe some very important points are made.

Anyway, Ken starts off by saying:

“Thank you for the reply, even with its own posting, and my apologies for not getting round to responding in turn until now – I needed time to digest.

“Your impression was correct, of course… I didn’t agree with you :-).

“Reading the fuller and more developed version of your thoughts, I agree a lot more, but I suspect we are still somewhat at odds. Perhaps we may find that we do agree?

“I thought I might respond point by point, if that is OK:

“You say:”

So let’s try to explain, in a little more detail, why I think the advice to roll off the throttle when confronted with a bend that the limit point suggests is tightening is wrong.

First and foremost, it doesn’t help machine stability. Keith Code is very positive about this – we should be able to role on the throttle from the beginning of the bend to the end in one smooth action.

Specifically, if we’re turning, then loading the front end with a closed throttle doesn’t help the machine steer. We’re not talking racetrack geometry here, but bikes designed for the road, wearing road profile rubber and ridden by road riders – don’t believe everything you read in Performance Bikes about bikes turning better hard on the brakes!

“I say:

“As a fellow alumni of the California Superbike School I agree absolutely that rolling back on the throttle doesn’t help machine stability. If we were talking about corners with wide open visibility on the road, however tight or nadgery the corner in question, then I suspect we would be in total agreement; brake in a straight line if required to get to the desired entry speed, turn once with a single countersteering input and then open the throttle through the corner. If it tightens halfway round and you can see exactly how tight it is, and that it opens out again after it tightens, and that there are no upside down wheelie bins, diesel spills or builders skips in the way between you and the point where you would come to a halt if you had to stop ‘right here right now’ then just lean it over further and keep the throttle cable tight. That, after all, is why we all ride motorcycles, and it has the advantage of both being more fun and safer as well, assuming you aren’t already knee down in an attempt to emulate your BSB racer of choice on his fastest ever lap of Cadwell Park, anyway.

“But, just to state the blatantly obvious for a moment, if a corner is blind on a race track, it goes without saying that you know where it went during your last lap, less than 2 minutes ago, so you know exactly where it will go this lap, how much grip there will be, etc – so you can afford to take the risk of riding it from memory, and rely on the people with the orange boiler suits to wave flags at you if there is somebody elses’ burning motorcycle blocking the track just past the apex next time you come round, or if the track is now wet and greasy or covered in oil, or if there is a slow moving vehicle just out of sight.

“On the road, if there are high hedges or walls or trees, you just simply have to be able to stop between where you are and the limit/vanishing point is, because you have no idea what is just past it. 99, 999 or 9,999 times out of a hundred/thousand/ten thousand the answer may be ‘exactly what you were expecting’, and maybe of the times when it isn’t, 99 out of 100 surprises are things you can improvise your way around if you are good enough and paying enough attention at the vital moment. But eventually, if you rely on memory, signs placed by fallible human beings and past experience to tell you what to expect just past the vanishing point on the tightening corner you are half way round, you are going to skate past the limit point on a blind corner while futilely trying to shed speed and either plummet to your doom off a cliff or become impaled in grisly fashion on a very spiky piece of parked up agricultural equipment.

“Hence my contention that you simply [i]have[/i] to slow down mid corner when the limit point moves towards you mid-corner (assuming a blind corner, on the road). I would have assumed that the only argument would be over how one goes about it.”

OK, what we need to do is differentiate between two things.

Firstly, most of our riding time is spent dealing with the commonplace twists and turns of the road, in which case I refer you to what I said several paragraphs on in my original reply; if the vanishing point shows only minor changes of radius, and we’re not using huge lean angles but have plenty of lean (and grip!) in hand, then a speed that allows us to ‘stop in the distance we can see to be clear on our side of the road’ really does mean that any minor change of radius CAN be dealt with by changing lean angle rather than the speed of the machine. Such corners don’t need to be “wide open visibility” because as I also said it’s very rare that we ride into any kind of bend to find a hairpin on the other side of it without some inkling that we’re riding into trouble!

This is the point I was really trying to make in the original comment on the IAM book – that our ‘default’ approach to the commonplace SHOULD consider the basics of good throttle control and machine stability first and foremost, simply because we SHOULD be able to read the road well beyond the vanishing point… and if we CAN’T gather such information, that very lack of the knowledge of what’s beyond the vanishing point should IN ITSELF be a clue to reduce our speed well below the ‘stop in the distance we can see is clear’ rule so that we aren’t caught out by an unexpected hairpin.

But if the ‘roll off as the vanishing point moves towards you’ advice is followed as a ‘default’ approach (which is clearly how the IAM book intends it to be followed!) it leads to the absurd situation where riders treat what Ken describes as wide open bends in the same way as tight blind corners – they roll off the throttle to the apex, then wind it on again as they see the vanishing point opening up, totally ignoring the fact there IS a wide open view and the bend could be dealt with perfectly acceptably by changing mid-turn lean. I followed a bunch of IAM riders on a ride out up in NW Wales some years back doing exactly this down the coast road, and there was no justification for it whatsoever.

Now, none of this is to say “nope, I refuse to shut the throttle because it’s poor machine control” if I felt I could deal with the hazard by the kind of mild reduction in speed I could achieve by rolling off the throttle but I do it in the awareness it doesn’t aid machine stability rather than thinking it’s good machine control.

And quite clearly, limiting our response to a tightening bend by ONLY closing the throttle is still poor advice – sooner or later we’ll meet a situation mid-bend where we’re going to need to do more than roll off!

Thus we need to differentiate between the first case I’ve just described where the bend itself is a predictable hazard and a second case where we need to deal with an emergency mid-corner. This could be Ken’s ‘Mad Max’ style farm implement blocking the road or the invisible hairpin (despite what I’ve said about reading the road, they really do happen, if rather infrequently!). We’ll come back to this in just a moment.

Ken continues by making a point about stability when decelerating:

You say:

They’ll never feel it, that is, right up to the moment they shut the throttle mid-corner on a greasy surface as the corner tightens slightly!

At that moment, the nice ‘planted’ feel of the front tyre will vanish as the slip angles reverse and the slip angle of the front exceeds the rear. The result is a nervous, edgy feel from the front end, as the bike begins to understeer.

I say:

Absolutely agree. But I feel it’s it’s a graduated thing. If you actually _close_ the throttle, a lot of weight will transfer onto the front tyre and you are risking a lot. If I actually feel I need to do this to shed enough speed for the next part of a bend, I’d rather stand the bike up very rapidly using countersteering while still on a positive throttle, brake nice and hard to shed a lot of speed in the minimum amount of time safely (modern ABS makes this far safer than braking while lent over in my humble estimation), then drop it back into the corner, again using rapid countersteering, but travelling at a much lower speed so that I can then ride the next, tighter section on a positive throttle again. However, gently and subtly moving from e.g. a slightly leading throttle to a slightly trailing throttle will cause you to slow down, all be it gently. and will transfer some weight to the front tyre, but not very much. Certainly a lot less than using the brakes would. It feels right, it doesn’t feel like I’m loading the front end enough to worry it, common sense tells me I’m not loading the front very much, I’m nowhere near the grip limits of the front tyre on the road because of the need to be able to stop in the distance I can see to be clear etc and I’m very conscious of the need to finesse the transitions from positive to negative throttle and back to positive so that they are butter smooth, any time I am leant over, to avoid the shock loading on the front contact patch that comes from all that weight transfer going ‘Oof!!’ as it hits the front springs.

The reader (if there are any left!) will probably be pleased to know I have a very short answer to this!

Leaving aside ABS for the moment, if we can finesse your use of the throttle by closing it and opening it gently, so we can finesse your use of the front brake by applying it and releasing it gently. It’s the mirror image of feeding power in progressively as we exit a turn, a technique which many riders would use without a second’s hesitation or even much of a thought, even though overdoing it and the consequent loss of grip at the rear will usually result in a highside. And of course we can use both brakes together.

But the key point that I made in my initial reply is that the brakes WILL slow us faster than a closed throttle… and as the speed drops, the lean angle reduces and we can apply steadily more brake just as we can apply more throttle on the way of of the bend as the lean angle reduces because of reduction in speed. Braking upright tangentially to the corner is an option that’s ok on a constant radius bend but probably won’t work on a decreasing radius turn because there’s unlikely to be space to stand the bike up; if there is, it may well mean our speed is low enough we can negotiate the turn by leaning more anyway!

Ken continues:

“Actually, I wasn’t specifically positing the problem of entering a sweeper that turns into a hairpin. If you enter a corner at a speed consistent with being able to stop in the distance you can see to be clear then we agree absolutely, it should be absolutely no drama whatsoever. It was a more insidious combination than that I was suggesting… it was a sweeper that tightened a little bit, so you thought you’d deal with it by leaning a bit further, and then tightened a little bit more so you leant a little bit more, and of course because you had loads of lean and grip in hand when you went in to the corner in the first place you have no problem doing this. Except that now you are going to struggle to stop in the distance you can see to be clear because you are turning tighter and going faster than you were at corner entry when presumably you were calibrating your speed to be able to stop in the distance you could then see to be clear. And NOW the road throws you a hairpin, or a 90 degree left turn over an old single track stone bridge or a farm trailer, but now because you have been sucked in by the comparatively gently tightening curves that you decided to negotiate by leaning over more without rolling off, you are at close to full lean and have no time or space to shed the speed you need to shed to get round the next corner (or avoid the parked combine harvester/herd of cows/etc).”

It’s important to emphasise that what Ken’s talking about here aren’t huge and unexpected one-off foul-ups. Riders simply don’t have crashes where they are carrying far too much speed to get out of trouble with any frequency. In fact, they are very rare. Accident studies around the world suggest that with a very few exceptions (usually cruisers with limited ground clearance) the bike COULD have made the turn and usually with plenty in hand.

Rather, we’re into the territory of what the US airforce rather graphically calls a ‘clusterf*ck’, where a series of small and avoidable mistakes all add up to put the rider into a situation they cannot get out of. Nevertheless, my reading on research into bend accidents suggests that riders very rarely actually back themselves into a corner (sic!) that they COULDN’T have got out of even when the mistakes add up. Had they been aware of, and corrected, any mistake in the chain they could have escaped without drama. But they failed to correct any of them and eventually the chain of errors catches up with the riders.

Even at the very last moment the weak link was the rider applying the wrong (or NO) input in the last seconds before the crash – Keith Code realised this and identified these inappropriate responses to the threat of harm as his slightly dramatic but none-the-less highly valid ‘survival reactions’.

So, in my opinion, Ken’s right; theoretically, you could end up by applying the throttle ‘stability rule’ running too fast into a situation that we can no longer avoid because we didn’t slow down earlier.

But he’s also wrong; the chances that we don’t spot some kind of warning of danger earlier in the chain of events are really pretty darn low. And there’s still no good reason we can’t use the brakes to slow down if we really think “danger ahead”!

And even if we do get into trouble, we need to understand that the bike’s abilities to steer (and stop!) are well beyond what we ask of the tyres and brakes on a day-to-day basis, and that having confidence in the machine will virtually always get us out of the kind of trouble Ken suggests.

The key point here is that it’s vital to actually learn and practice techniques like positive countersteering (to change direction faster rather than to apply big lean angles) and braking in bends so that we bump up our levels of confidence, rather than to apply a demonstrably faulty technique in the hope it’ll eliminate any chance of things going wrong a few seconds down the road.

I’ve talked about this idea that if we apply all the right techniques, nothing will ever go wrong. I call it the ‘Holy Grail’ approach to riding and it’s a totally flawed view of safe riding.

Ken continues:

“Also with regards to signs, I never want to be ‘that guy’ – the one who piles off the road into a ditch and later says ‘not my fault, there was no sign warning me about that bend!’. Signs, road markings, chevrons etc are great, and damned useful, especially where they tell you about things that you can’t easily see, like concealed hazards, but generally if e.g. I see (err… don’t see) a dip between two crests on an empty road ahead of me, it is 50 feet deep until proved otherwise. I don’t look for a sign saying ‘Warning, concealed dip’ before I make that assumption. And every unknown blind corner might have a hairpin the other side of it, lack of sign not withstanding. Clearly interacting with the world I ride through this way may make me seem overly cautious at times, but the clear advantage of it in my mind is that it promotes a mindset that leads one to focus very much on what the road I am riding is doing right now, today, not what it has always done in the past. And given that today MIGHT be the day that I find an upturned tractor in the middle of my favourite shell-gripped sweeper, that has surely got to be a rider safety benefit…”

As Ken says, the absence of a hazard warning sign does not mean “NO HAZARD”, and we have to look for problems as we ride. That’s a given. But the presence of a sign generally warns of a hazard we CAN’T see; at least not until we are too close to the hazard to deal with it safely. That’s what signs are for. There’s a lovely road in mid-Wales I take the trainees on when I’m running courses in Mongomery. Seven or eight miles of undulating, twisty road… then about five miles in, there’s the ONLY bend sign on the road. It warns of the very problem Ken’s worried about – the blind corner with the hairpin on the other side of it.

I don’t think that anticipating every corner can get worse before it gets better or that the road might be totally blocked out of sight is “overly cautious”; rather I think it’s a realistic and pragmatic way of dealing with bends and it’s exactly the way I ride corners. I might not come ever across an upturned tractor but several times I’ve come across stray farm animals or parked farm equipment that couldn’t be seen.

But neither does it convince me that the blanket advice to roll off the throttle when the vanishing point moves towards me is in any way the right approach to being realistic and pragmatic about hidden dangers. None of this negates what I said right at the beginning about getting the speed down on the approach to a blind bend by using the brakes positively and upright!

Ken then quotes me as saying:

Which leads us to the brakes. Ken mentions getting the bike upright and braking in a straight line. It’s an option, but generally I’ve found that unless I’m already scraping the undercarriage, if I’ve room to do that I’m not going too fast to simply lean over more and make the turn anyway.

But on occasion we have to slow from speed to a near-stop. Unless we’ve made a total mess of reading the bend, it’s more likely to be forced on us by an obstacle in the middle of the bend rather than simply a bend that’s tightening up dramatically, but nevertheless, let’s continue the logical explanation.

There’s a far better technique than standing the bike up to brake, and that’s to brake in the curve. In point of fact we’ll lose far more speed far more quickly by applying the brakes than we’ll ever manage by closing the throttle!

But we’re told that braking in corners is a no-no. But racers do it on the track all the time. All that’s really needed is a bit of understanding of the issues and some finesse with the controls.

The most important is probably to realise that if we’re leaning over and we haven’t already fallen off, there’s grip available to brake. There may not be much if we’re carrying a lot of lean, but if we’re still on two wheels, there is by definition some spare traction for braking.

We also need to be really smooth and subtle with our application of the brakes and we need an equally smooth release. True, the bike tries to sit up as the brakes go on, but we can deal with that with a little firmer application of countersteering pressure.

Given that we SHOULD go into any bend able to stop in the distance we see ahead in the bend, at the first sign the bend is tightening significantly we’ll still be at only a moderate lean angle and we can use the distance we can see ahead to get on the brakes and start losing some speed before the bend tightens up.

“I’ve certainly done my share of mid-corner braking in the past, after cocking up spectacularly. Here’s why I think the balance of arguments between standing the bike up and braking hard, and braking leant over has changed these days…

“It’s absolutely true that if you need to shed a lot of speed mid corner in a hurry then the brakes are a far better option than chopping the throttle, for all the reasons stated above. But the problem with braking mid corner is that it has always been a bit of a lottery. Yes, the bike tries to stand up, but you also initiate weight transfer rear to front, at the same time as you demand more from the front tyre by adding braking forces to the cornering forces you are already applying. So you are limited in the amount of brake you dare use for risk of locking a wheel while lent over and ending up in the scenery. Locking a wheel in a straight line can be recovered from, although it screws with y6our stopping distance, locking a wheel lent over in a corner is not going to end well.

“Of course you can pull the bike tighter into the turn before the turn actually tightens, then use rapid countersteering to stand the bike up, brake and then throw the bike back on its side again, and you can of course brake harder if you do this, but at the expense of the fact that you are not braking while you are tightening the turn or standing the bike up, and of course you still risk locking up the brakes and not shedding the speed you need to so again you can’t brake as hard as you might want to to gain sufficient advantage from having turned the bike more tightly, then flicked it upright and then flicked it back into the turn to make it worth the delay. I always thought it was swings and roundabouts, and depending on which bike I was on determined which approach felt most naturally comfortable, not that I made a habit of needing to do it.

“I believe that modern motorcycle ABS has changed all that. Broadly speaking, if you brake while lent over and overcook it on a bike equipped with ABS you will still end up in the hedge, so you are still not going to brake as hard as you can while lent over. By contrast, with modern motorcycle ABS, if you stand the bike up you can basically drop anchor as hard as you like on as nasty a surface as you like and the ABS will sort it out and slow you down as quickly as it is possible for you to slow down, without any risk of getting out of shape. Even on a good surface you can afford to treat the ABS as your safety margin.

“So, I’m no more of a fan of braking mid corner than I ever was, but if I need to do it because I have cocked up or because the world has conspired against me, I’d much rather stand the bike up and throw both the anchors out the back than try to finesse the brakes against the cornering forces while leant over…”

Ken’s made some valid points, but only one of my four working bikes has ABS fitted, and whilst it’s no longer a rarity it’s still going to be a long while before ABS comes fitted to a majority of bikes (though the EU may have something to say about that in the next couple of years) let alone existing bikes in use.

But as I’ve said, from the technical point of view braking in a bend is no different to opening the throttle leant over, a skill many riders have already achieved. As I’ve already mentioned, both braking and accelerating mid-turn comes with a penalty clause, it’s true, but that doesn’t mean we shouldn’t use the techniques if we understand how to get the best out of them whilst avoiding the worst of the risks.

Conclusions from this discussion?

I think despite detail differences which I hope I’ve explained, I do think we agree on the machine control advantages of turning the bike through the bend on positive throttle as a better control technique than roll-off / roll on approach. I think I can safely say Ken and I also agree on the need for a pragmatic “it can get worse before it gets better” approach to blind bends which determines speed of entry. I think we also agree that braking mid-turn may be necessary though we don’t agree on the best approach.

But I do believe that much of the time better observation, planning and positive use of the brakes before arriving at the bend would negate the need for the “roll off at the vanishing point comes towards the rider”; maybe we’d go in a bit slower, but we’d also deal with the hazard better.

I think if there’s a real difference, I feel it’s in that I have a bit more confidence in riders and their abilities to use techniques like braking mid-turn selectively and not to make the kind of gross errors where they totally fail to spot a hairpin round the next bend.

About Kevin Williams / Survival Skills

Motorcycle trainer, motorcycle author, motorcycle safety consultant, motorcycle forum moderator, former courier and ever a recreational rider. Is there a common theme here?

Discussion

2 thoughts on “Tightening bend – slow down or lean over more? Part 2

  1. I think what this discussion really indicates is that if you approach riding from the perspective of the physics of the machine, you get the right answers to good, solid machine control techniques, and that in turn decides how you deal with problems on the road.

    I really believe that a lot of the advice in Roadcraft has remained totally static since the days of 50hp Triumph Saints and BMW R75s, running skinny tubed, crossply Continental and Metzler tyres! Plus, of course, it never hurts to remember that the book was never intended as a ‘bible’, just a study guide to go with a practical training course. It just amazes me that with all the riding expertise there undoubtedly is within the IAM that they still publish advice which is demonstrably faulty.

    Interesting what you say about the Beemer front end. Years ago when anti-dive was all the rage, my brother bought a CBX550 which had adjustable, mechanical anti-dive where twiddling a small screw progressively shut down the size of valve controlling the flow of oil under compression. It didn’t prevent dive, it slowed it down (I guess it was actually an early form of compression damping!). It was simple and in theory seemed like a good idea.

    In practice, it took away the feedback under braking, and he’d only had it a few days when he crashed it under braking on a slippery surface, and whilst some blame can probably be pointed at “unfamiliar bike” with rather better brakes than his previous CB550F-K as a reason, I rode it myself a few days later and had only gone a mile or so when I got off and turned the anti-dive down from max, where he’d set it just before he crashed, to minimum where the forks dived under braking like normal!

    I recall reading somewhere or other (I must sort out a proper referencing system like Malcolm Palmer!) that BMW themselves discovered when trialling the first telelever prototypes that the dive under braking is at least part of the way that a rider judges how hard they’re braking and that zero dive was counterproductive – they actually needed to dial in some dive, just so riders could get some feel from the front.

    The discussion has also reminded me that there’s no “one size fits all” approach. Over the years I’ve owned a variety of machines from my first CB400F through a whole series of other machines (interestingly I’ve never ridden a triple!) of various styles. At the extremes were an NX650 Dominator and my classic ’92 GSX-R750. It’s true the Dommie required a rather different braking technique to cornering, but virtually the first thing I did with the Gixxer was turn the front end compression and rebound down, back to standard initially and eventually settled on a couple of clicks softer than standard as I felt that was the best compromise between feeling what the front tyre was actually doing and steering – at the end of the day, I could deal with the fork dive, but knowing that the front end is doing is paramount.

    Tyres are another tuning device that affect riding technique. Once I find a tyre I like, I tend to stick with them. At the moment, I’m using Conti Motion. It’s not a tyre that’s got much heavy press time, but one that gives excellent stability, good feedback, and progressive lean when turning – it doesn’t make the bike flop on its side like some Bridgestones I’ve used. They work on both the Hornet and the XJ6. Interestingly my XJ6 came with Dunlop Roadsmarts (OK but the rear squared off badly and wore out far too fast), yet the other OE tyre that the XJ6 came fitted with is a Bridgestone that flopped nastily into corners – it definitely demanded a different approach to braking and slow turns.

    Which makes me think bike set-up is a topic for another article at some time. There are no hard and fast rules, despite the enthusiasm with which riders get out cable ties to measure front end dive and metre rules to calculate static sag after reading yet another article in Performance Bike. 😉

    I’ll see if I can take you up on that offer to ride in Wales sometime!!

    Cheers

    Kevin

    Posted by Kevin Williams / Survival Skills | September 29, 2011, 9:43 am
  2. Hi, Spin!

    Thanks again for the in depth reply. We seem to be agreeing more the longer this goes on!

    I’d just add that this discussion has made me think about things I’ve not really analysed for a while, for which I must thank you, and I think I’ve just cottoned on to another reason why I have preferred to stand the bike up to drop anchor if I need to shed a lot of speed mid corner in the last few years than I ever used to; BMW front ends! My main 12000 mile a year plus bike has changed twice in the last 7 years, but has had ABS AND a funny feedback-free front end for all of that time! Whenever I ride a bike with proper forks now, I am simultaneously aghast at all that nasty dive on the brakes, and amazed that I can actually feel what the front end is doing and know when I’m pushing my luck with it. I’m sure if I rode a traditional giant trailie I’d be a huge fan of gentle progressive mid corner braking and dead set against standing the bike up and braking hard, because of all the suspension geometry changes that occur under hard braking and their affect on cornering. By contrast a BMW will let you brake like a demon in a straight line without the front end diving at all, but give you no clue whatsoever how close you are to the limit if you are loading the front mid corner.

    As for any remaining subtle differences of view, I’m sure the only way of quantifying them would be for us to ride together at some point. Perhaps next time we are both in Wales at the same time? I have some lovely roads to show you around the Llandovery area, if you are at all interested…

    Posted by khaylock | September 28, 2011, 1:27 pm
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