Woody

Oh yes, and what he said... get yourself booked on a level 1... :-)

Sounds like this could be a number of things... But... it could be a simple matter of gripping the bars too tightly and so not giving the bike a chance to settle into the turn. It's quite common for a rider to unconsciously stiffen up, tightening their grip and keeping the bars turned, effectively steering the bike into the ground (also manifests as running wide on the exit). Next time you go out, to reduce distractions, slow everything right down and then try forcing yourself to relax your upper body (your grip should be fairly relaxed and you shouldn't be using the bars as a support). Try to think about what you are doing, your position on the bike, your grip on the bars and how this changes when you start cornering. My hunch would be that you're stiffening up when you're heading through tight corners and this is giving you the feeling that you're falling. Your worry is only creating a vicious circle where you unconsciously tighten your grip even more, which only makes matters worse. Sure, check your suspension also (this could well be worn and there's certainly nothing to be lost by giving it an overhaul), but generally, failing any serious mechanical problems (which would pretty much show themselves in a straight line/ gentle corner as much as the tighter stuff), the main cause of ill handling bikes can be traced back to what the rider is doing.

The natural instinct is to turn the bike, or else we'll die(!). The brain sees a corner and thinks "got to turn, got to turn, got to turn" and then what happens? We turn and apex early. Understanding this is crucial to imroving your cornering for both track and road. With track riding it is much easier to practice different approaches to a corner, as you know what is going to be around the next corner and, riding in circles allows you to try different approaches for the same corner easily. Road riding is a different beast, as it is often the case that you don't know what is going to happen and so forming a plan of approach is much more difficult. Because of this, your brain tends to throw a wobbly and do what it thinks is safest, head to the inside of the corner as soon as possible. In effect, you need to retrain your brain and I found that the best way to do this is by thinking about sighting. I know that my eyes are the most important part of my skill set and I also know that good vision is paramount so that I can form a plan for each corner. Knowing this, I find that my riding adjusts automatically for road or track riding. For example, whilst road riding I will at times lean away from the bike to give myself a better view rather than to improve my ground clearance, this may even require me leaning 'the wrong way', depending on the conditions (you should never be so close to the limit so as you can't adjust your body position on the road), whilst on the track, after a few laps I will have a fair idea of where the track goes, so I can concentrate more on improving my corner speed (I'm still slow mind you, but then I am old and greying!) and so will spend less attention on getting a great view of the track and more on getting a better weight distribution on the bike. I'm still looking ahead, mind you, but just so I can see where my turn points are. Woody

Also try doing as Cobie suggests and reduce the play on your throttle cable, it helps enormously.

Got to agree with Cobie and kwh. Laaate apex for street riding. Not necessarily the fastest way through the corner, but much much safer and you'll find yourself making fewer mistakes as a result of having good sighting. There are so many unknowns with street riding that the approach must be different to track riding if you are to stay alive.

I would have said that as a general rule of thumb, the less drive you have, the closer you should be to the 'classic' line (nice wide arc). If you have a big powerful engine (as a MotoGP bike would have), I expect that you'd be wanting to use as much of that power as you can (otherwise what's the point in having it), so you'd be looking to pick the bike up early so you can get as much drive as you can, as early as you can. The basic theory would be that a powerful engine can make up any shortfall in mid corner speed by going faster at the corner exit (which also leads to greater speeds on the straight bits)... I expect that the rider's weight distribution will also have a greater effect on corner speed for smaller bikes. To corner faster, the rider positions their weight more to the inside of the corner. The lighter the bike, I expect the greater effect this will have, allowing you to pick the bike up further than you would a heavier bike (or, allowing you to go faster for a given lean of the bike). Also, 125 GP bikes are a bit slimmer than MotoGP bikes, so you probably gain a little extra clearance there too. What is it that ultimately limits corner speed? Lean angle! Don't mind me, I'm just thinking out loud...

We're heading toward some very rough waters here. Lean is a necessary byproduct of cornering forces. It is what stops the bike from flipping over whilst cornering. It is what gives the bike balance through a corner. The amount of lean is relative to the speed of the bike and the rate of turn. Lean more and you'll either take a tighter line or you need to go faster to retain the same rate of turn. The front wheel points into the turn. The amount it points into the turn is just the right amount to achieve the right arc for the given lean angle and speed (we set the arc through steering input and the lean follows). Turn the front wheel more or less and the bike's amount of lean changes. (Change your speed, by the way, and you change the arc.) Without cornering forces, the bike needs no lean and to generate cornering forces, the front wheel needs traction. What sort of traction would be present if the bike was at 90 degrees from upright? This will decide the state of the front wheel. The only scenarios I can think of where traction would be present are: 1. A banked corner 2. A wall of death (which is effectively an extreme banked corner) For 1. the bike would be cornering just as normal, with the front wheel pointing into the corner. For 2. the front wheel would be straight. For a flat turn, the bike would be on its side, no traction would be presented to the tyre and the direction of the front wheel is immaterial.

Whoa, that set the old nogging spinning. For a given speed, the more a bike leans, the more the front wheel points into the turn. Also, the bike lean should be understood in relation to the road. If the road is already banked, the natural line for a bike that is 'upright' (90 degrees in relation to the road) is to follow the banking and at this point it is safe to say that the bike is not 'turning'. To put it another way, if a turn is banked you need less lean to get around it than if the turn was flat. Your example of the 'wall of death' is a perfect example of taking this to the extreme. A bike going straight, yet also changing direction.

Excellently put, Racer.

I can't help but feel that the precession theory is fundamentally flawed as it is only considering the effect for one wheel, the front. When you apply the precession theory to the front wheel only then it appears sound, but this is only part of the story as bicycles and motorcycles also have a rear wheel that is connected to the front via the frame and is fixed by the swing arm (so that it is unable to twist). When the front wheel is turned, due to gyroscopic precession, the wheel will try to lean. I think we all agree that this is right, nobody has disputed this. This 'lean' will also be transmitted via the frame to the rear wheel, which (applying the very same theory) will now try to twist. However, the wheel will be unable to twist because of the swing arm. Because it will be unable to twist, the rear wheel will resist the precession effect of the front and will try to remain upright. In short, the rear wheel, being fixed by the swing arm, will resist the lean induced by the front. There will be some flex in the frame and I am sure that the bike turning will also negate the resistance a little, but I don't feel that these will be significant enough for precession to be considered anything other than having only a minor effect on the steering. Happy New Year, by the way.

I confess to using the front only. I've tried using the rear, but so far have found that all this does is use up too much of that precious $10 for no apparent gain. Perhaps it is something that I should continue with, but then I am perfectly happy as I am (I don't feel as though there is any real benefit to using the rear). Even low speed. I've tried it and still do, but again I really haven't seen any benefit in using it, or reason why I should.

I wouldn't know where to begin to produce a video or animation, but think that these would be a great idea. Instead, I'll try to summarise what I've said previously in as simple a way as I can. Steering is simple. A motorcycle/ bicycle will try to go to wherever the front wheel is pointing. Period. (Remove the words 'try to' if you want to be really simple.) In longer words, point the front wheel to the left and the bike will try to go left, point the front wheel to the right and the bike will try to go right. When we start to learn how to ride a bike, we learn very quickly that to turn a bike at any kind of reasonable speed we also need to lean it. We find this out through trial and error and it becomes instinctive (we don't need to think about it) very quickly. Our brains are clever enough to deal with all of this without our making any conscious effort to work out any complicated physics. 'Countersteering' is the method we use to lean the bike. This is the instinctive bit (the bit we don't think about ... until we go to the cornering school or read Keith's books). Here we need a little understanding of physics (inertia). Whilst moving in a straight line, when we turn the handlebars, the front wheel tries to go in that direction. However the rest of the bike doesn't know this and wants to continue in a straight line. Because the front wheel is going in one direction and the rest of the bike is going straight on, the bike leans over. Hold a broom handle upright against the floor and kick the bottom. It's effectively the same thing. A video would be great here. As the bike leans, the weight of the bike, combined with the steering geometry, forces the front wheel to point into the turn. I struggle here to put this into words simply enough (as I probably don't understand the physics well enough). I have mentioned some practical experiments earlier. These may or may not be very good or relevant, but I'll repeat them anyway. Whilst moving slowly forwards, turn the handlebars and note what happens. The bike will try to go in that direction. Do this at any speed and the same happens. Take a really tight turn at low speed (a U turn is perfect). You will be travelling very slowly, so any gyroscopic forces should be minimal. Note what happens. First you need to lean the bike and you do this by turning the bars away from the turn. Next you'll find that the bars will turn into the corner (you may even need to catch them to stop them from turning too far). Hold a bicycle by its seat and lean it over. Note what happens to the front wheel. It turns to the direction in which the bike is leaning, or into the turn. Maybe the above aren't the best descriptions and I've no doubt the professor that Ulrich directed us to could do a better job. That was excellent reading. Please guys, flame me all you like. I think I'm right, but don't we all Hey Racer, no no plans to head to Tassie again any time soon. Just returned from a trip down the Great Ocean Road though, caravans and all (NZ next Christmas, DEFINITELY!)

G'day Racer, how's it hanging? As does a single bicycle wheel, rolled at an angle. This would appear to support the paper cup theory (and is probably what inspired it). However, a motorcycle has two wheels, not one. Roll two bicycle wheels, one behind the other, both at the same angle and the same speed and each will follow the same arc, but each will be at a different position in the arc. Because of this, they will not be in line (one directly behind the other). The leading wheel will, relative to the second, be pointing more into the turn than the following wheel. It's a similar story with a motorcycle (although yes, there are differences as both motorcycle wheels are connected by the frame). Need... mince... pies...

I would say that you are mistaken. Whatever force you are applying to the bars, the front wheel must be pointing into the corner for the bike to make it around the turn. The same applies with the 'paper cup' theory. The front 'cup' needs to be pointing into the turn to make it around the corner. If we fixed both wheels, so that you couldn't turn the handlebars and both wheels were held firmly in line, if you lean the bike, my belief is that it would continue in a straight line and just fall over. Regarding the precession theory. How many times have we seen motorcycles exiting corners with the front wheel in the air all crossed up? If precession is the force making the bike lean, turning the wheel this far would surely try to throw the bike on its' side. My guess is that we need to remember that there are two wheels on a motorcycle and that the rear wheel, being held firm, will resist what we are doing with the front. I have no doubt that gyroscopic precession and paper cups have an effect on steering, but I think this is merely complex 'fine tuning' of what is a fairly basic principle, that the direction in which the front wheel points is the direction in which the motorcycle goes.

It's funny how the subject of how a motorcycle steers keeps going on. It's a neverending circle. I have a theory that is much simpler. The lean is a necessary byproduct of cornering, which is required to counteract the forces pulling the bike to the outside of the corner. Without leaning the bike, it would tip over. Turn left, the bike tips over right. To put it another way, if you continued to pull the bars to the left, the bike would eventually fall over without turning to the right. Once leant, you need to release the pressure on the bars in order to allow the bike to turn. The bike actually goes around the corner because the front wheel is pointing toward the inside of the corner. I don't see it any other way. So, to initiate the turn the bike must first be leant over. Turn the bars to the right and the bike starts to turn right, this tips the bike onto it's left hand side. Once the pressure is released on the bars the steering geometry pulls the front wheel back around so that it is pointing into the corner and the bike starts to turn left. The amount of lean is directly related to the speed of the bike and how tight the corner is. Slow down and the bike will take a tighter line for a given angle of lean. I have three practical examples. 1. Take a turn at a relatively steady speed and roll off the throttle. What happens? The bike takes a tighter line. You need to pick the bike more upright to retain the same arc. (The opposite is also true, speed up and the bike takes a wider arc. You need to lean the bike over further to retain the same rate of turn.) 2. Hold a bicycle by the seat and lean it over to the left. What happens? The front wheel turns to the left. The steering geometry forces this effect. 3. Do a 'U' Turn. This is a very low speed manouver, btu due to the tightness of the corner, you still need to lean the bike. What happens to the bike and steering? You need to lean the bike, albeit only slightly, but which way is the front wheel pointing? To the inside of the corner. I have no doubt that gyroscopic forces have some effect, but I see this as very minor and if anything this acts to prevent the bike from cornering rather than assist. Just some thoughts for the pot. Not sure whether I have explained myself very well... Have a great, safe Christmas folks Woody