faffi

I think it was Freddie Spencer who, during long test sessions back in the old days, even got to the point of bleeding from his hands

You have less grip available for braking during cornering because somewhere between 0 and 100% of the available grip (depending on angle and speed) is used to counter centrifugal forces.

Interesting - thank you! Do students tend to end up with blisters as well after a long day at one of your classes, or does the relative lack of speed and aggression usually protect them?

We often see racers with blisters in their hands and many of them use sports tape to protect the skin on their hands. Obviously, this means they use a lot of force on the grips. Naturally, you cannot relax while using this much force. Yet I read a lot about staying relaxed, especially in the arms. Apparently, they will also vary their body position some up to 20 times around a corner (shifting which foot is weighted the most, moving back and forth on the seat to stop a spinning tyre or prevent a wheelie etc. etc.), another thing I would expect would demand that the bars are gripped at least some? So my question is; do the racers switch between relaxing and tensing much in the same manner as cross country skiers do, in order to conserve energy and keep blood flowing through their hands and forearms? Or does it take more or less constant fighting and a firm grip in order to win a GP race?

I think you can probably keep your head reasonably level with the horizon even if you hang in some. However, it wasn't my intention to draw this back into a lean in/lean out body position thing - it was based upon balance and how the brain react to having two horizons to relate to. I'll try to answer your question about how much attention I give it. It is automatic for me to tilt my head, but I quickly notice if I forget or if I somehow mismatched the two horizons a significant amount. That's the only time I'm aware of it, and I then correct accordingly. Doesn't happen very often. Then again, most of what I do while riding is based upon experience and instincts. Even when I first started out riding, things like when to start braking, or where to turn in, or where to get on the throttle were automated, done by feel. I'm talking myself into taking a course rapidly here, I feel BTW: Typically when riding, engine vibrations, poor throttle response, harsh suspension and butt burn are what draws my attention

I did a limited search on google with ["eyes level with the horizon" + motorcycle + corner] and got nearly 10,000 hits. I don't think every hit is relevant, but there are many other ways to phrase it that are omitted by the search. So I believe it can be said that it has enough importance for enough people to warrant some attention. It is also recommended practice by the MSF. Rating it? How do you rate anything that's heavily connected into a whole? How high do you rate the wheels over the frame on your motorcycle? I guess it will depend on just how poor the frame or the wheels are. If we ignore the obvious basics (having a working motorcycle in the first place and a head that can move), I would say that being able to keep my head reasonably in line with the horizon is very important for riding hard, not so much for keeping a touring pace. I would much rather ride fast (for me) on something like a V-Strom with full movement of my head than on a Gixxer with my head fixed horizontally. I would rather be able to tilt my head than have impeccable throttle response. I would rather ride with drum brakes than a fixed head position. Dunno if that helped any, but everything is intertwined and the answers will differ with the actual constellation. At least for me. EDIT: A link http://www.daytonamotorcycletraining.com/T...-motorcycle.htm

I do not think it's a personal preference - several pages have been devoted to the subject earlier, for instance in magazines like Cycle, Cycle World and das MOTORRAD. I doubt they would print it if it wasn't of a more general interest. For me personally, it is one of the most important aspects of riding for the very reasons described in my previous post.

I believe it is important, but I also believe that the effect will vary quite a lot from one individual to another. Just like some have better balance than others, some have better coordination than others etc. People vary in skill, what they can do well - or not. Personally, I am pretty sure that failing to keep my eyes level with the real horizon caused me to ride off the road back in 1991. I was, out of stupidity, occupied with looking at the instruments as I went into a corner. When I looked up, I was slightly off course and heading for the outside of the road. I felt confused because I had my head aligned with the instruments instead of the road, and simply failed to make the simple required adjustments and ended up with a tumble that wasn't very pleasant. For me, it is vital that I keep my eyes level with the horizon, something I have always done even before I learned why back when I was riding a bicycle. Just cocking my head sideways makes it really hard for me to even walk straight, and entering black tunnels will make me wobble on the machine unless I force myself to really relax and just rely on the bike knowing how to stay upright as long as I do not interfere. In other words, shutting my eyes also significantly upset my balance. As mentioned, this is likely to vary a lot from one individual to another, but for some I think it could prove life saving to keep a level head.

Our brains use vision and the inner ear to decide what's up and what's not. If you lean your head with your machine as you tilt over in a corner, the brain will have to deal with two horizons; the actual one and the one created by your machine as you lean - as indicated by the handlebars etc. This can lead to confusions that in some cases could result in making the wrong actions under stress. Keeping your eyes in line with the actual horizon becomes increasingly more difficult as you hang off the inside of your machine. So I wonder; is this thing a point you focus on during riding? How do you position your head during cornering and why?

Thank you both for elaborating on those final posts! I am, however, slightly confused about the statement quoted above. Keith Code, I believe, wrote that you get more rubber on the ground the further you lean. Obviously, this will only be true up until a point when you start to roll off the edge of the tyre. But assuming we stay away from the edge, should grip be reduced with more lean? Another thing that I thought was mandatory from a physical point of view, was that the centrifugal forces stay the same regardless of lean for any given speed. That is, if you hang off to reduce lean, you are still putting the same stress as you would with the bike pushed down and the body hanging out. And since the rubber touching the ground is more or less the same, it shouldn't matter anything. That is, until you reach very big amounts of lean. Being a street rider, however, that is usually not a concern of mine. I have no chicken strips on my BT016 rear and about 1/4 in strips on both sides of my BT001 front, meaning there should be plenty left in reserve before the tyres are struggling unless I really start to use a lot of brake of throttle midcorner. Another thing - for me - is that the nicest roads are the ones littered with hairpins. I prefer roads where the speed is generally less than 70 mph, at least around the corners. 30-50mph is the sweet spot. Changing the way I ride would undoubtedly be very beneficial on a track, though. I have tried to follow the more common advice of leaning over the fuel tank, relaxing my arms and shifting my body slightly inwards on street rides. I din't like it, even after sticking with it for a while. My pace was about the same, but it didn't seem natural. I've even tried to hang off a lot, but feel ridiculous. And my torso ends up more like Abe and Doohan did early on, with my head above the switchgear or thereabout. I don't lean drastically outwards, and sometimes I will shift my torso a little inwards because something in a corner can demand or make a change natural. Still, my movements are kept very slight. Sorry, I babble. As you were

Note body position in the link below. Why would motard riders typically hang their torso slightly to the outside of a corner? Is it for other purposes than to maintain control over the bike? I'm asking, because I really do not know, but it's pretty much how I ride my streetbikes on the road (not the sliding, the upper body position) while sitting still in the seat. On the road, leaning a little out has another benefit that I find highly valuable - I can see much further through a blind corner than what would be the case if I were hanging in.

Chopping the throttle - that's an instinct thing I have never been able to eradicate when things happen without warning. If I feel my corner speed is too high, I will stand it up a bit and brake as hard and as long as I need/can before continuing also. I know it's not ideal, but so far I haven't been brought down in these situations, surprisingly enough. When it comes to the two styles needing various riding styles, I agree. But I also think they they both have two wheels and an engine and that many of the same physical laws do apply. That's why I think you have a greater ability to manhandle a motorcycle in an MX position than hanging off to the inside - you can literally grab it by its handlebars and step on its pegs with far greater force should it be needed. I'll try to find one of the written passages from people with much more credibility than this old street rider that more properly describes why leaning out gives you a better chance to save a highsider than leaning in. If nothing else, it should further the discussions

There are times when I afterwards wonder how my brain (doesn't) work Especially when I repeat a former mistake - and knew why and how As to body positioning, I still believe pushing the bike down and keeping your torso high will significantly increase your chance to prevent a highsider to happen in the first place, reduce it's "energy" in the case it does happen, and make it simpler to save by being on the "right" side to have an impact on the forces. If you are already fully hanging off to the inside, there is nothing you can do but follow the bike and be thrown over, whereas the rider hanging the other way can throw himself inwards and in the opposite direction to the force of the upcoming motorcycle. MX riders, AFAIK, use a similar style, again to better control the slides and the slide-grip incidents that takes place all the time. I have never seen anybody who regularly hangs off to the inside of an MX bike, even though it should in theory benefit cornering speed. And to me, not being and MX rider but by observation, it seems much harder to control an "out of control" bike when you are on top of it. I wish I could explain this a bit better, but my lack of English vocabulary holds me back when it comes to some aspects regading the physics etc. involved

Absolutely. And when you have lots of grip on a chassis that lacks rigidity and suspension that lacks proper damping, it gets much worse, unfortunately. Something many a flying rider has had to learn the hard way I have survived two high sides; one violent, one much kinder. The kind one happened after a long day on the road in the rain on a cold day - the snow literally melted in front of us as we went. Every time we stopped, people told us the road had been white an hour earlier. We rode mostly in slush or just lots of standing water. Anyway, in the evening all the remains of the snow had gone and I decided - from boredom or a frozen brain, really cannot tell - to just lay my old XS500 down to the muffler around a sharp right hand hairpin. The Michelins gripped fine until just past the apex when a one metre wide "river" of water crossed the road; remains of the melted snow coming down the mountain side. The rear end immediately stepped out until I was at full lock. I chopped the throttle and rapidly placed my inner foot to the ground, the slide stopped and the bike came back on track, just nudging me off the seat. The violent one was on a CB1100F. I was leaned over completely around a lefthander, scraping stands, peg, exhaust and nudging the engine cover, doing about 55 mph. I was in second gear and for whatever stupid reason I just whacked the throttle open. I was sideways instantly (probably in slow motion compared to what we have seen on TV during races, although it was instant for me) but managed to chop the throttle. The rear gripped, compressed the suspension and came back in a wonderful catapultic move. This not only kicked me out of the seat, but into a headstand. I was literally hanging by my fingertips looking backwards, my legs so high I couldn't even spot them. I watched the bike go from side to side underneath me, and by some miracle it was directly below as I landed back onto the seat. Luck and possible the strength from years of doing powerlifting saved the day - skill was not involved.

Unexpected question (for me) that I'm very interested to hear the answer to - and more importantly, the follow-up answers or -questions!

Actually, the highsides came as a result of the tyres being better than the chassis, so that they would let go very suddenly without much warning. Adding the abrupt power delivery of the two-strokes, highsiders seemed inevitable. People with far more understanding than me about these things have commented on how various riding positions offer various benefits (or not) with mentioning about the physics involved that make it more likely to save a highsider (which isn't the same as saying it is likely); Cameron, Ienatsch, Roberts and more. And it does make sense if you think about it - if you want to prevent something from rising, would you stand on top of it or laying under it? Or if it was a catapult, do you think you'd be thrown the furthest if you were hanging at the tail end or sitting ahead?

It seems that the latter position, with the whole body hanging well to the inside, is the most commonly used today. During the days of the big two-strokes, keeping the torso more upright seemed more typical. Most likely because it increase your chance of catching a highsider. In fact, pushing the bike down MX style and hinging your body in the opposite direction is the best insurance against a highsider position wise. If you hang far to the inside when the rear tyre lets go, you have a long way to travel and your body will accelerate to motion. If you are already haning the other way, you can instead use your body to counter the highsider. Since highsiders are pretty rare these days, getting more weight to the inside in order to keep the bike as upright as possible for any give cornering speed (usually meaning leaning over the same but going faster) seems more rational.

Wow - is that even mathematically possible

As long as you know what you are doing, sliding the tyres will make you faster. Top rank riders use sliding to quicken the steering and whatever, they gain several seconds per lap from it. Actually, to be absolutely correct, you cannot accelerate or decelerate without slip. And slip is sliding. And steering needs acceleration of some sorts. So what we are talking about here is the transition between controlled slip and a complete lock-up. Also, I suppose a tyre can be locked up in one direction and rolling in another, which would be sideways sliding under speed. BTW, I followed and read the link you pasted, and it - to me - failed to give any new answers to what's been discussed under this topic.

We at the school are kinda all about using logic to break stuff like this down to specifics. That's kinda the point of this thread. Might not always work, but if we can find something that will work a large percentage of the time I think it is a worth while discussion. Sorry if it sounded like I was implying otherwise - I was more hinting that the theories are flawed in actual life for some reason or the other in that even the best of the best cannot always adhere to them. Probably because we as humans aren't sensitive enough to put them to use under all conditions. A bit like knowing how all robbers look like, but since nobody can cover 360 degrees 24/7, you can still get robbed

Interviewed by Soup about the old Honda Superbike based upon the CB750F, Haney said: Yeah, just what I do

Welcome! I'll second that about the snow! Hope you'll enjoy your Beemer - personally, I lack sufficient self preserving sense to ride good handling fast machines on the road

Considering your occupation and who you work for, the answer is with all probability that yes, you can put it into words It still doesn't prevent even the best of the best to get caught out, so obviously the transition from grip to slip can at times be very abrupt and the line too narrow for even riders like Pedrosa or Stoner or Rossi etc. to be able to react at all before they are down. In my opinion, this suggests that you cannot just use logic or break it down to specifics and always make it work. Apparently - and this fit with my own experiences - various tyres have different characteristics. Some may have a very wide window between where they start to slide until they actually let go completely, others will have a razor edge and hence be far more demanding to reach the limit on. Then you have tyres that doesn't act consistently, which must be the worst. Personally, I feel that the tyres feel vague when they start to let go, a sensation as if they are slightly floating over the road surface. It's not a feeling I enjoy much, and the faster I go, the less I like it.

Perhaps you just got a bad GoPro camera? One wouldn't imagine a product could become the highest seller if it didn't work as a rule?

That's the very reason, khp, why I always make the corner as wide as possible. Not only can I see much further around the corner, but it also keeps my head as far out of harms way as possible. Turning in the opposite direction, I will sit closer to the oncoming traffic, but this is more than outweighed by the improved visibility ahead. And should the oncoming traffic be too close for comfort, I can tighten my line. Surprisingly often, that oncoming traffic is a rider crowding the centre line and leaned into my lane.