All about Corners, Counter steer, counter measures

[w1n6]

  Quote

Originally posted by AspMonK@Apr 20 2005, 12:54 AM

wah... no color become color pic...ahahah

no prob MonK

[weiz85]

very useful tips to pick up!

[br1an]

great stuff folk check out the book by keith code : "twist of the wrist" its a racing manual but many basic race technique can be learn from there and thing like countersteering and mental training are also included, very good for improving ur survivability on rd too

[SweetChild]

  Quote

Originally posted by br1an@Sep 1 2005, 07:43 PM

great stuff folk check out the book by keith code : "twist of the wrist" its a racing manual but many basic race technique can be learn from there and thing like countersteering and mental training are also included, very good for improving ur survivability on rd too

where to get that manual? hehehe

[SweetChild]

nice articles there...

[ET]

wooOo....CORNERING BETTER....

[Denden]

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The SV takes the off-camber corner!!!

[-dUde]

hey bout conerin....i juz gt into an accident..can u guys refresh me abit,lets say ur goin at high speed corner and u wanna slow down to control e corner...do use frnt, frnt n back,back brake or engine break...??which is more advisable??

[desmokat]

fornt brake le.. then down a gear to lower speed more.. if no need to lower speed.. just brake.. then throttle through the corner... all depends la..

[Guest czh2002sg]

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Originally posted by desmokat@Dec 20 2006, 09:47 PM

fornt brake le.. then down a gear to lower speed more.. if no need to lower speed.. just brake.. then throttle through the corner... all depends la..

Using the front brakes IN a corner is a definte no no. You should do all your braking and drop a gear or 2 before entering the corner. Slow in fast out leaves you more reaction time in the corner. Should you really need to brake in the corner because of a tightening turn, rear braking by gently tapping and releasing repeatedly offers the safest braking, if you can't drop another gear in time. This is because a rear slide is more recoverable than a front slide. Front tyres locking will mostly result in a lowside slide. Tapping the rear brakes gently and releasing repeatedly and quickly works in the same way ABS does, albeit a manual, rider controlled form of ABS, which is not always reliable, unless you are familiar with your bike, or you're Rossi Have a safe ride

[w1n6]

advise

[edalpha]

nice articles n great advice dude !!

 

[Strong Eagle]

  Quote

Originally posted by czh2002sg@December 27, 2006 09:27 pm

Using the front brakes IN a corner is a definte no no. You should do all your braking and drop a gear or 2 before entering the corner. Slow in fast out leaves you more reaction time in the corner. Should you really need to brake in the corner because of a tightening turn, rear braking by gently tapping and releasing repeatedly offers the safest braking, if you can't drop another gear in time. This is because a rear slide is more recoverable than a front slide. Front tyres locking will mostly result in a lowside slide. Tapping the rear brakes gently and releasing repeatedly and quickly works in the same way ABS does, albeit a manual, rider controlled form of ABS, which is not always reliable, unless you are familiar with your bike, or you're Rossi Have a safe ride

I am in general agreement with you comments but would like to add a few more observations about braking in corners.

 

One of the problems you find in braking in a corner is that you have a shift in weight towards the front of the bike. Of course this happens in a straight line as well but in a corner you could unload the rear tire enough that it coulc go into a low side skid.

 

This would be especially true if you are increasing the braking on the rear wheel. Thus, if I find myself entering a corner too fast, I will first attempt to use rear brake pressure to slow the bike but if that is insufficient I will use the front brake for more stopping power. When the weight shifts forward as a result of braking the front brake can be braked more before it loses traction.

 

There is one other serious problem with using only the back brake. If you lock the rear wheel and feel like you are about to go into a low side skid, then release the wheel completely, you have a real good chance of ending up in a high side skid as the rear wheel attempts to come back into a single track.

 

The obvious answer is speed control coming into the curve but if you do not estimate correctly then begin with light to moderate back braking which shifts the weight then apply front brakes to further slow the bike.

[Guest czh2002sg]

On better cornering, I humbly suggest every rider bring his bike to a race track at least once. Its the safest place to understand yourself and your bike better in corners. Almost any bike also can, and any rider also can. Use the parts of the tyres you have not used before, enter it faster than you ever had. You'll gain a new understanding of yourself and your bike. Lastly, go with more experienced riders and learn from them, and do ask them to wait for you on the ride there. Its boring for first timers, especially 2B bikes like me. Corners kenna lap, straights, sure kenna lap, one hours kenna lap 3 or 4 times by the same guy. But all in good fun and understnading myself better in corners, which is... definitely a lot more than practical in Singapore riding already. Unless... You go to May Hong Song Loop in Northern thailand. Dunno how's its spelled. 1600+ corners, some off the cliff. Hope to go there one day, but I'm not ready.

[Denden]

czh2002sg really giving out sound advice here... we get together and we learn.

 

Thumbs up!!!

[squallgoh]

up up up!

[Pplater]

Ah yo Den, its not like its my advice lah. I learn from other people, including you and then circulate loh. refreshes my theory also. yup, we get together and we learn

 

pplater aka czh2002sg

[gnayed]

Then again, upon braking in mid-corner, you will find your bike uprighting on its own if you brake hard on your front brakes, so it isn't exactly a problem. Unless you are bent on shedding some cornering speed while leaning on probably because you are drifting outwards from your intended line, then rear brakes are generally the way to go.

 

However, I don't really think tapping your rear brake is the right way to do things. By consecutively tapping your rear brake, you will upset the weight shifting more compared to constantly applying gentle pressure to it. Just imagine going on and off the brakes, you will have your springs rock you forth and back. If the rear happens to lock up like SE mentioned, it's only going to flip you into a bad high side by tapping it on and off again. So it's probably better to just continue locking the rear and low side it.

 

The pulsating of ABS works so quickly that you don't exactly physically feel the brakes going on and off, so there is actually a difference. The track junkies will tell you upsetting the load and CG is the last thing you would want to do in mid corners.

[w1n6]

Ok guys, this was what I did the last time during mid corner to save my ass from kissing another bike ass, low side or high side.

 

Close throttle and graduate pressure on the front brake so the force would bring the bike up and while the bike is almost vertical, full brakes front and rear. Depending on the cornering speed, the worst scenerio is crossing on to the opposite speed bump and ride over the grass at much lower speed.

 

Give it a practice during track session

[Pplater]

Hmm... I believe you are riding a big bike? Yeah, big bikes will stand almost automatically if you brake the front hard during corners. Had a friend on big bike with inline braking grabbed the front, and whole bike stood up as you mentioned. Big bikes tend to be heavier and will upright itself, with more weight transfer to the front allowing more braking before losing traction, but small bikes that are lighter will have the front lose traction more quickly without first uprighting itself unless the rider upright the bike first. Its usually grab and kerbummmmm..

 

Also, for small bikes, even in straights, rear braking does not really shift the weight forward much as compared to class 2. Small bikes have lighter weight, and the posture of say, a class 2B sportbikes is nothing like class 2 sports type of forward-leaning posture. The weight distribution is more to the rear comparatively between a NSR and a GSX? Most postures of class 2B will have more weight sitting on the rear, which makes it less likely to lift up, but big bikes are still heavier and allows more braking without losing grip? And their more powerful brakes also cause the bike to shift its weight forward more quickly with either brakes. Small bike however, can't really feel much of weight shifting forward with rear brakes, even if you jam them on straights and control the fistail. Heavier riders may be able to rear brake more without locking the rear. All these this may make rear braking or trail braking a somewhat easier technique in corners, nothing like the real thing on a big bike which takes more skill to control and carries more risk. Not sure what I'm saying correct not... Still L plate on these things

 

Hmm... The reccomended technique for rear braking in a corner would be to gently depress the rear brake and hold? I've always been tapping on the rear on the rare occasion cars in front start to slow down mid corner and engine braking is insufficient.

[boofeng]

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Originally posted by Pplater@May 01, 2007 01:36 pm

Hmm... I believe you are riding a big bike? Yeah, big bikes will stand almost automatically if you brake the front hard during corners. Had a friend on big bike with inline braking grabbed the front, and whole bike stood up as you mentioned. Big bikes tend to be heavier and will upright itself, with more weight transfer to the front allowing more braking before losing traction, but small bikes that are lighter will have the front lose traction more quickly without first uprighting itself unless the rider upright the bike first. Its usually grab and kerbummmmm..

 

Also, for small bikes, even in straights, rear braking does not really shift the weight forward much as compared to class 2. Small bikes have lighter weight, and the posture of say, a class 2B sportbikes is nothing like class 2 sports type of forward-leaning posture. The weight distribution is more to the rear comparatively between a NSR and a GSX? Most postures of class 2B will have more weight sitting on the rear, which makes it less likely to lift up, but big bikes are still heavier and allows more braking without losing grip? And their more powerful brakes also cause the bike to shift its weight forward more quickly with either brakes. Small bike however, can't really feel much of weight shifting forward with rear brakes, even if you jam them on straights and control the fistail. Heavier riders may be able to rear brake more without locking the rear. All these this may make rear braking or trail braking a somewhat easier technique in corners, nothing like the real thing on a big bike which takes more skill to control and carries more risk. Not sure what I'm saying correct not... Still L plate on these things

 

Hmm... The reccomended technique for rear braking in a corner would be to gently depress the rear brake and hold? I've always been tapping on the rear on the rare occasion cars in front start to slow down mid corner and engine braking is insufficient.

hi zh,

 

whether big or small bikes, you can wash out when applying front brakes. the factors are not really "big" or "small" bike, but front wheel grip (and lean angle). perhaps because bigger bikes tend to have better tyres, a bigger contact patch, a more front-biased weight distribution, better suspension, etc (all things which help improve front end grip) you came to your conclusions.

 

also, when you apply rear brakes, weight distribution actually goes to the rear, i think.

 

re: technique for using rear brakes into corners.... i agree with what gnayed says: braking continuously while in corners would be more stable than on/off application. being prepared to release the pressure somewhat once it slips might be a good thing? i guess it would feel a lot like modulating a power-slide (bike's version of drifting) with throttle control, only now you're using rear brake control. i think it'll really depend on situation. notice that very few bikes do power slides in superbike racing? but it's almost a pre-requisite for motard races? one of the reasons is the difference in risk of high-siding (and maybe rate of tyre wear). so for low speed corners, maybe applying some rear ABS-style (brake til it slips, let go, and brake again) is okay, but for fast corners... hey why are you keeping so little reserve in a fast corner anyway?!

 

anyway, back to the real question: how best to slow down in a corner while already leaned over? i've no idea. i hope i'll never be in such a situation! thinking about it frightens me already. it seems to me that generally (because there're so many variables really) using the rear is safer, because you can recover from a rear slide but not from a front. as for tapping, i think steady application is more controllable, but being able to release pressure slightly once it slides might help save the rear slide if it happens (applying rear like ABS).

 

it really depends la. i think most of the time when we're riding, we're not leaned over so much to the point where loading the front that little bit more with front brakes will cause a wash out. so in everyday riding, we should be able to slow down in corners with both front and rear, only we should perhaps biase it more to the rear, and definitely not jam the front due to risk of low siding.

 

ok this is the end of theory-craft.

let's go track to practice some day! ride safely everyone!

[gnayed]

  Quote

Originally posted by Pplater@May 01, 2007 01:36 pm

Hmm... I believe you are riding a big bike? Yeah, big bikes will stand almost automatically if you brake the front hard during corners. Had a friend on big bike with inline braking grabbed the front, and whole bike stood up as you mentioned. Big bikes tend to be heavier and will upright itself, with more weight transfer to the front allowing more braking before losing traction, but small bikes that are lighter will have the front lose traction more quickly without first uprighting itself unless the rider upright the bike first. Its usually grab and kerbummmmm..

Erm... Nope, I believe this phenomenon applies true to small bikes as well (I did it on a Wave and Phantom). Infact I've not tried grabbing front brakes on my later rides (the bigger bikes). What I would do is just trail brake on the front abit in the midst of leaning in to cut some lap times.

 

Boofeng:

I believe you can't control a slide by rear braking at maximum lean because you are either locking up the wheel or spinning it. Spinning the rear back up to speed from a brake lock-up at full lean on a high speed sweeper will surely flip you onto a high-side (according to my experience), whether you recover from it or not depends on your luck.

 

I've not played motard (so pls correct me if i'm wrong) but according to my knowledge of controllable rear sliding is, you cannot lock up the rear, or at least not at full lean. What motard riders do is they actually drop gears to create a difference in spinning speed of the rear tyre and bike travelling speed to lose the traction. In this way they do not lock up the rear but infact just induce a difference in travelling speeds. Or either that, they grab hard on front wheels to force weight shifting on the front wheel to lose traction on the rear, but the rear is still spinning.

 

Then again, I've seen stunt riders induce slides by jamming up the rear brakes on an almost upright position, then give it throttle to overpower the rear while leaning in to execute the drift. Actually, it is perfectly alright to trail brake into corners, because our front tyres can take more grunt more than you think. But don't bet on it.

[ANR Impex]

The tendancy of the bike to stand up under braking is due to the caster of the front wheel (More on Caster angle). Caster angle helps with stabalising the front wheel and is what lets u ride hands off and maintain a straight line.

 

Bikes with more relaxed steering angle (forks that are less steep in angle from the horizontal) have large caster angle and are very stable straight line machines. The small amount of front wheel frictional drag is amplified through the large caster angle to keep the wheel pointing straight. This makes the bike reluctant to turn as well.

 

In a turn, the steering is just so slightly turned. When the brakes is applied, the effect is to tremendously increase the frictional drag acting through the front wheel, forcibly straightening the wheel. You stand the bike up and go straight, it's what the caster angle is designed to do. Applying the rear brakes will not do this as the frictional forces does not act through the front wheel. I have crashed once standing the bike up braking to arrest a tank slap mid turn, this is with a super4.

 

That said, modern sportbikes have steep forks with very much reduced caster effect. They brake wonderfully well into a turn and is much more effective at slagging off speed in a turn than applying the rear brake with all the weight transfer to the front. The brakes must be applied smoothly with the body already shifted to the inside of the turn to offset the 'standing up' of the bike. This straightens the bike a little while maintaining the turning radius, reducing the chance of the rear wheel breaking loose.

 

I cover my front brake in a turn and have no problems coming to stop quickly when leaned over.

[boofeng]

gnayed: hmmm, yes. apologies about my comparison of this with controlling power-sliding, which is indeed a quite different situation (though the point that a high-side due to rear wheel skid is less likely at lower speeds should still be relevant). power-sliding is over-spinning, our situation is under-spinning; and in power slides, you deliberately make a controlled slide to square the corner, in our scenario, losing speed is the priority, not using slides to choose a better line (though that could be useful depending on what kind of obstacle you encounter). it would be more appropriate to compare with how ABS works.

 

i agree with you that recovering from a completely locked rear wheel would be impossible for most ordinary people under general conditions, as you described. the thing is, it need not be from a complete lock, right? ABS does not wait for a complete lock to occur before it kicks in, it detects skidding based on difference between wheel speed and vehicle speed. the question is, can humans feasibly do something similar? to know that there're many questions:

 

for a given scenario (speed, lean, tyre, geometry, etc etc),

1. how long, after initiating a skid, does it take the wheel to lock up, given careful brake application?

2. how long does it take for the front and back wheel to become misaligned?

3. can the human detect the skid, and take corrective action, in less time than required for (1) and (2)?

 

once (1) and (2) happens, it becomes the situation you describe, which is virtually impossible to recover from. if we can react in time, perhaps there's a chance of recovery from the skid.

 

for (1), i wondered very long about how fast a wheel would lock up once it loses traction. i'm not sure... my brother asked me to put my bike on main stand and try it. in a high gear, with throttle closed, it seems like it'll be quite easy to lock, and once it's locked, recovery is impossible.

 

for (2), depends on the sharpness of the corner and the speed of the vehicle. it could be really short, or you might actually have a generous margin. no idea at all.

 

 

so what are the implications of all these on road riding? since we don't know much about (1) and (2), and since (1) and (2) might be very different for different scenarios (e.g. 80kmph vs 140kmph, angle of lean, tightness of turn), maybe this discussion is pointless. like gnayed and ANR Impex (and myself) have said, there's usually more than enough allowance left for front braking, when road riding. so maybe.. i don't know, it's better to use the front than to risk a sliding rear?

 

that said, we do know of people who've lost their front ends in corners before, right? (i've lost mine at sub-50kmph, very little lean, under gentle acceleration through a damp corner, but with bad tyres and badly adjusted suspension) every situation calls for a different response? knowing the limits of your bike would help somewhat in choosing the right response for the right situation.

[Pplater]

Wahahaha... I dunno whether to laugh or to cry. After reading the posts this afternoon, i went out trying to do my normal braking deliberately with the bike leaned at an angle. My bike initially did not stand automatically. I later realized the reason was that i only braked gently. Nor did my weight shift to the front, because i didn't brake hard enough. I tried to moderate braking and it stood upright automatically. The funny part was i got surprised. I think its funny because I've been cornering in those 270 degress flyovers between expressways and never got to to do hard braking mid corner for almost a year already such that i forgot what its like to do so. Reading about safer street riding made me pick up habits such that for almost a year, after i buang, i have not had to brake hard enough in a corner to stand the bike. Usually i glance at the exit which is on left of the entry as i enter it to gauge what the exit speed would be like, and end up holding constant speed in the corner and accelerating at the exit. On the rare occasion, traffic is held up at the exit, because i went into the corner slow, i usually uprighted the bike myself first immediately before braking. I guess staying off the brakes in corners as advocated by many in this forum, the proper techniques of slow in fast out have made me forget the dangers of braking deep into corners. All those stickies in this thread kept me safe in corners until i genuinely forgot braking hard enough stands the bike up. Dunno whether to laugh or to cry.

 

I think this is a testimony to Endlessloop's method of riding, the HOV concept. Check out Street Smart thread. Coupled with the rest of the stickies in this forum, I've actually managed to post something stupid in this thread which goes like "braking in corners does not stand the bike up". Need to dig a hole....