Emergency stop practice - gear change problem

**scracha** · 8th March 2010, 21:16

Engage the front first, followed almost instantly by the rear.

Originally Posted by p.dath

Lets just say that emergency braking technique is highly contentious, and there is considerable disagreement over the use of things like the clutch.

Yep. As per usual I pretty much disagree with most of what p.dath is saying. As usual I'm going by my own experience and DSA UK guidelines produced after considerable research by chaps far more learned than I. P.dath is yet again relying on one little study based on a handful of riders and a tiny amount of testing.

Regardless of of differences, most importantly go out and practise. See what feels better and stops you quicker.

**p.dath** · 9th March 2010, 10:24

Originally Posted by Tryhard

Engage the rear brake, shortly followed by the front brake.

The rear first? is that for real?
I think I maybe practising the wrong way!

The rear brake is only of use while there is weight on the rear wheel. As soon as that weight is gone the rear brake is of little use (I think even scracha will agree with me on this one ...).

As soon as you apply the front brake hard the weight will rapidly transfer onto the front wheel.

Now this is where people's opinion will vary, and this is most definitely my opinion. You should consider what different people say, and come to your own conclusion.

Dis-engage the clutch and apply the rear brake immediately. Briefly stablise the bike and yourself on the bike if needed (and I mean briefly), and then get on the front brake hard. Re-adjust the front brake pressure as needed.

EDIT:
Just read scracha's reply,

Engage the front first, followed almost instantly by the rear

- so we are in complete disagreement.

**p.dath** · 9th March 2010, 10:50

This appears to the the DSA guidelines (from the UK) for an emergency stop:

http://www.bikerforum.co.uk/forums/n...otorcycle.html

The Emergency stop tests your reactions and ability to stop the bike at speed as quickly and safely as possible. It is generally taught as a 5 point system.

1. Shut off the accelerator.

2. Apply the front brake.

3. Apply the rear brake.

4. Increase the pressure on the front brake.

5. Apply the clutch to avoid stalling (on a manual).

Once again, it makes little sense to me to apply the rear brake once the weight has been removed from it. The numbers in the study I sighted are still the best evidence I have seen. Someone actually measuring it.

Until I see a better study, I will be holding to it.

**Coldrider** · 9th March 2010, 11:04

I scored a trackday coached by Brian Bernard and Freddy Merkel back in 2001.
Upon learning emergency stopping procedure it was front brake only, learnt how to do stoppies at the same time.
If there is a KBer who is World Superbike Champion more than twice they may correct me.

**centaurus** · 9th March 2010, 11:06

After extensively practicing emergency braking and normal braking with and without clutch, I have found a middle way: First start braking with the clutch engaged to take advantage of the engine braking. If it's a normal braking I will go down through the gears but if it's an emergency one I don't (saves time). Once the revs do quite low on the engine, I pull the clutch in to prevent stalling (engine braking at that point is quite low anyway). Dependin on the engine, the cut-off point is different. For an inline4 like mine, once the bike goes below 2-3k rpm it's useless, for your GN, even in top gear, engine braking should be good up to 1k rpm (or close by).

If you pull the clutch in when you start braking, you will not slow down as fast as with the clutch engaged and the risk of locking the rear wheel is quite high.

If you shift down through the gears you either blip the throttle which will reduce your breaking (you will inadvertedly slightly release the front brake lever while working the throttle) or don't blip in which case it's bad for the transmission and you risk locking the rear wheel and dropping the bike.

Try emergency braking (in a parking lot) with and without the clutch and see which one feels better and stops the bike faster.

As for gear changes issues, some bikes are worse than others - I've had my share. A few things that work: if you are standing still, try slightly engaging the clutch. That will move the gearbox cogs just enough to make it work again, or you can just move the bike forward/backwards. If you are moving and the revs of the engine are too high or too low for the speed and gear you are trying to engage, even with the clutch fully pulled in, some bikes will not go into gear. Some gearboxes just do nothing, other will push back the gear changer pedal (you can feel it on your foot). If that is the case the revs need to match the speed and gear.

**Crasherfromwayback** · 9th March 2010, 11:23

Originally Posted by Coldrider

I scored a trackday coached by Brian Bernard and Freddy Merkel back in 2001.
Upon learning emergency stopping procedure it was front brake only, learnt how to do stoppies at the same time.
If there is a KBer who is World Superbike Champion more than twice they may correct me.

Fred Merkel was indeed a great racer. But just because he doesn't use the rear brake doesn't mean you can't or shouldn't. Ever seen the size of the rear disc on Nicky Haydens bike?

Nicky Hayden...you know...the guy that beat Rossi for the world title!

**Coldrider** · 9th March 2010, 11:29

Originally Posted by Crasherfromwayback

Fred Merkel was indeed a great racer. But just because he doesn't use the rear brake doesn't mean you can't or shouldn't. Ever seen the size of the rear disc on Nicky Haydens bike?

Nicky Hayden...you know...the guy that beat Rossi for the world title!

I knew Carl Fogarty would turn up sooner or later.......just kidding.
It is really about personal preference, what your mind and body does instinctly in the situation.
When the back wheel is 600mm of the deck and your mind is on keeping the forks compressed and front wheel almost locked, a little rotation and a bit of smoke, how do you have the mind to work on the back brake, that is off the deck?

**centaurus** · 9th March 2010, 11:35

Originally Posted by Crasherfromwayback

Fred Merkel was indeed a great racer. But just because he doesn't use the rear brake doesn't mean you can't or shouldn't. Ever seen the size of the rear disc on Nicky Haydens bike?

Nicky Hayden...you know...the guy that beat Rossi for the world title!

Depending on the bike type, there might be more or less weight on the rear wheel, which determined the ammount or rear brake you whould be using. On sport bikes most of the weight is on the front (about 10% of the braking is on the rear). Some people use the rear to compress the front and as they progressively squeeze the front lever more, the reduce the rear brake pressure (progressively also). The more front brake you have the less pressure the rear wheel has on the ground and the risk of locking the rear is higher. Also, you need to remember that rear brake is mainly used on sport bikes for slowing down or leaning more mid corer for those situations when you realise mid corner you have too much speed. for that alone and a bid rear brake is helpful at racing speeds.

Mathematically speaking using the rear brake too will add almost 5-10% more braking power but the risk of locking the rear being so hight, most people do not use the rear when emergency braking. If you are good enough to REALLY be sure you won't lock the rear, go ahead and use it, but if in doubt, 5-10% (for sport bikes) procent less braking power is a price most people would gladly pay in return for canceling a high rist of rear wheel locking. It's a matter of personal choice, based on how much experience do you have and how much you know your bike. Nobody can tell you if you should or shouldn't be using the rear brake in an emergency braking.

Of course, when talking about other types of bikes that have more weight on the rear, the situation changes drastically: on some bikes you can go up to 40% braking power on the rear in which case you simply can't ignore the rear brake.

**dipshit** · 9th March 2010, 11:37

Originally Posted by Coldrider

When the back wheel is 600mm of the deck and your mind is on keeping the forks compressed and front wheel almost locked, a little rotation and a bit of smoke, how do you have the mind to work on the back brake, that is off the deck?

In the first initial part of the braking - your back wheel will not be in the air. You are dreaming if you think it will be.

**Coldrider** · 9th March 2010, 11:39

Originally Posted by dipshit

In the first initial part of the braking - your back wheel will not be in the air. You are dreaming if you think it will be.

The idea is to get the back wheel off the deck.

**dipshit** · 9th March 2010, 11:41

Originally Posted by Coldrider

The idea is to get the back wheel off the deck.

The idea is to stop as quickly as possible.

**howdamnhard** · 9th March 2010, 11:41

I agree with centaurus and p.dath regarding emergency braking. In a true emergency stop situation I don't have time to engine brake. Rear brake helps initially but loses traction as weight comes off rear wheel. I don't even bother about rear near the end and concentrate soley on not locking the front. Pulling the clutch prevents stalling the engine and allows you to get out of the way(been there and done it). If you have too stop relatively quickly but not use emergency stop then I use downshifting of gears. If you should inadvertently lock up the rear(by downshifting to far) just pull the clutch in to regain control.
Sometimes the bike needs moving slightly to get the gears to engage. My GN used to not like changing to nuetral from first if stopped,used to let the clutch out slightly and let it creep forward and then it would normally engage. My ZZR sometimes does it as well.

**Coldrider** · 9th March 2010, 11:44

Originally Posted by dipshit

The idea is to stop as quickly as possible.

Correct, that was the purpose of that particular lesson.

**Crasherfromwayback** · 9th March 2010, 11:49

Originally Posted by centaurus

Depending on the bike type, there might be more or less weight on the rear wheel, which determined the ammount or rear brake you whould be using. On sport bikes most of the weight is on the front (about 10% of the braking is on the rear). Some people use the rear to compress the front and as they progressively squeeze the front lever more, the reduce the rear brake pressure (progressively also). The more front brake you have the less pressure the rear wheel has on the ground and the risk of locking the rear is higher. Also, you need to remember that rear brake is mainly used on sport bikes for slowing down or leaning more mid corer for those situations when you realise mid corner you have too much speed. for that alone and a bid rear brake is helpful at racing speeds.

Mathematically speaking using the rear brake too will add almost 5-10% more braking power but the risk of locking the rear being so hight, most people do not use the rear when emergency braking. If you are good enough to REALLY be sure you won't lock the rear, go ahead and use it, but if in doubt, 5-10% (for sport bikes) procent less braking power is a price most people would gladly pay in return for canceling a high rist of rear wheel locking. It's a matter of personal choice, based on how much experience do you have and how much you know your bike. Nobody can tell you if you should or shouldn't be using the rear brake in an emergency braking.

Of course, when talking about other types of bikes that have more weight on the rear, the situation changes drastically: on some bikes you can go up to 40% braking power on the rear in which case you simply can't ignore the rear brake.

Yeah...each to their own. Bruce Ainstey uses quite a bit of rear brake...I don't and was able to regularly out brake him. What ever suits the individual best is the best way.