I purposely wasn't commenting on the pic
I purposely wasn't commenting on the pic
Actually it's the same exact effect when the bike is sliding.
The bike's inertia and grip want to make the bike highside, so you have to keep the bike leaned over. You do that by countersteering.
At that point, there's a delicate balance between too much lean angle, which could cause the rear wheel to completely let go, and too little, which could cause a high side. Furthermore, the grip available is also controlled by the longitudinal slip ratio, which is controlled by the throttle.
Interestingly enough, as complicated as it sounds, it's pretty natural when you're actually doing it. At least, that's what I've gathered from the few small slides I've had before.
The bike's inertia and grip want to make the bike highside, so you have to keep the bike leaned over. You do that by countersteering.
At that point, there's a delicate balance between too much lean angle, which could cause the rear wheel to completely let go, and too little, which could cause a high side. Furthermore, the grip available is also controlled by the longitudinal slip ratio, which is controlled by the throttle.
Interestingly enough, as complicated as it sounds, it's pretty natural when you're actually doing it. At least, that's what I've gathered from the few small slides I've had before.
They must have been really small
I'm just saying, steering to correct a slide is not the same as steering to deflect the wheels to one side. You steer into a slide to increase the radius of the arc you are travelling, to reduce the load on the rear tyre and to halt the rotation of the motorcycle.
Imagine, mid (for example, right hand) corner, half leaned over, not pushing hard at all - rear tyre locks. On a car park, no obstacles, the object is just to keep the bike upright asap. You react fast enough, which way do you steer? Push the outside bar (steer right) to straighten the bike up (as you would have done before), or away from the corner, into the skid?
I think i've got it. What I tried today, was instead of trying to "do" it, I tried to just "notice" it when I turned, and I noticed that no matter how hard I tried NOT to use it when I turned, it just came second nature.
I did a few little tests too, I drove at some pretty good speed (maybe 30 mph) into the back of a parked van, and tried to use accentuate my turn with an excessive amount of countersteering. I've noticed that if you TRY to be excessive with it, it becomes allot easier to stably take sharp turns.
Feeling allot more confident in my street riding now, thanks guys
I did a few little tests too, I drove at some pretty good speed (maybe 30 mph) into the back of a parked van, and tried to use accentuate my turn with an excessive amount of countersteering. I've noticed that if you TRY to be excessive with it, it becomes allot easier to stably take sharp turns.
Feeling allot more confident in my street riding now, thanks guys
Lol... yeah, wtf is that about...??!!
Neither. You gently lift off the rear brake and it comes back in line. Too fast, though, and it'll snap back and highside. Same thing for a throttle-induced slide, just gently roll of the throttle and it comes back in line.
No, you misunderstood, or perhaps I didn't explain the situation well enough. You're not on the brake at all, the rear locks up for no apparent reason (say something wedged in the drive chain gets stuck in the rear sprocket).
AFAIK, that's an extremely rare occurance if it happens at all. That said, if it happens while you're leaned over, you're pretty much screwed.
Then you're f*cked.
But you're only half leaned over, nowhere near the limit, and you react fast enough, and you don't have to worry about crashing, you're in a wide open space, you just have to keep upright. The question is not: will you stay up, or how likely is this to happen? It's, which way do you steer?
Yeah, he crashes because he panics and has no empty car park to steer into.
Anyway, this is going even further off topic than it was before. So: Yeah countersteering- steer one way the bike will lean the other.
Let's assume the average bike has a max lean angle of 45 degrees. Half of that is 22.5 degrees. That's still a pretty large angle, and if you completely lock the rear wheel under this condition, you're going down, no question about it.
Assuming the bike pulls 1 lateral G at 45 degrees, you can figure the bike pulls about .4 G's at 22.5 degrees from normal. In my book, that's still a lot of lateral force for a locked wheel to cope with.
The guy in that video was also not leaned over very much at all when he locked the rear wheel, maybe 5 or 10 degrees tops.
Assuming the bike pulls 1 lateral G at 45 degrees, you can figure the bike pulls about .4 G's at 22.5 degrees from normal. In my book, that's still a lot of lateral force for a locked wheel to cope with.
The guy in that video was also not leaned over very much at all when he locked the rear wheel, maybe 5 or 10 degrees tops.
Details. Not the point.
Fine, rather than "half" I'll say "gently", or in case you'd prefer 11.567 degrees at oh, let's say 30.128mph. Doesn't matter anyway, because you seem to be arguing that you'd steer further into the corner instead of away from it.
PS: I appreciate you removing your opening line
I disagree, I can easily resolve a locked rear wheel when leant over, done it on the road, done it on the track, done it on the Nurburgring, and it's easily savable if you know what you are doing.
Now, a locked front wheel?, anything other than totally upright and you are going down no question.
@danowat: I just want to be clear, sinbad and I are talking about a completely locked rear wheel, not a quick skid to get the bike sideways. As I mentioned, I find it hard to believe that such a situation is managable.
@sinbad: I'm an engineer (recent graduate anyway). I deal in details. Analysis of specific situations is impossible without them.
And yes, that (deleted) first line in my previous post was in rather poor taste. My appologies.
@sinbad: I'm an engineer (recent graduate anyway). I deal in details. Analysis of specific situations is impossible without them.
And yes, that (deleted) first line in my previous post was in rather poor taste. My appologies.
30 mph into a stopped vehicle seemed like a pretty good recreation of a typical motorbike crash to me :|
Not that fast, I agree, but I thought it'd be good enough for practice.
Countersteering
(68 posts, started )
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