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Discussion Starter #1
Twice now in a week I've had to slow down suddenly and my rear wheel has started to slide and lose traction. The first time was my cemented-headed fault where I decided to take my eyes off the road and was about to slam into the back of a car stopped at freeway onramp light...a light I thought wasn't going to be active for the time of day....so looked up and squeezed the brakes hard (front and rear) and the bike started swerving in the rear so I let up off of them and luckily was able to go around the stopped car but bike almost went down.

Then today going about 65 tried to suddenly slow down for a yellow light and the same thing happened so I went through it....I actually shouldn't have slowed down but noticed a cop sitting at the other light...which is why I initially didn't hammer through the yellow.

My Wing and XX never did this stuff when I braked hard.

This is the lightest bike I've ever had....anyone else have the rear get unsettled during hard braking? It's not very confidence inspiring. :?
 

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Forget the rear brake exists. It will do nothing but get you in trouble during hard braking.

The most likely reason for your rear end problems is you had the rear wheel locked up. Being fixated on the rear end which can never contribute more than about 10% of braking power almost caused you to hit a car. Not good! The rear brake is a major cause of accidents for exactly the reason you described. Too much of it causes the rear wheel to slide which distracts the rider from using the front brakes really hard.

Another possible cause of rear end issues during braking is the forks are bottoming which causes the rear end to weave back and forth. This can be solved by adding 10-15 mls of fork oil to stop the forks bottoming.

Put a zap strap around your fork leg to see how much travel you are using.

I can't say it enough. FORGET THE REAR BRAKE EXISTS You will live longer for it.
 

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It's just too much rear-brake. The weight distribution and wheelbase is much different than the wing or an XX.


Less rear brake and plenty of front will carry you through fine.
 

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Discussion Starter #4
CDNSVS said:
Another possible cause of rear end issues during braking is the forks are bottoming which causes the rear end to weave back and forth. This can be solved by adding 10-15 mls of fork oil to stop the forks bottoming.
I didn't replace the oil but got new racetech springs and forks don't dive much under braking anymore....I think it's more of me jamming the rear brake.
 

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CDNSVS said:
I can't say it enough. FORGET THE REAR BRAKE EXISTS You will live longer for it.
Or you can master it and get at least 10% better braking. :wink:
 

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Also check your rear sag... You may not have enough... causing the front wheel to lift ever so slightly from the ground....

It happens to me on hard braking at times... especially when using the back brake...

Check your sag... go from there.
 

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Discussion Starter #7
I know the process for measuring sag vaguely but have never done it. I did crank up my preload in the back to level 5 and the front is set pretty stiff....like maybe 3 rings visible. That plus the stiffer springs could mean I don't have enough sag....I could let it out a few notches front/rear.
 

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dont even bother using the rear brake on dry pavement.. assuming you are downshifting correctly you should have enough engine braking so that you dont need the rear
 

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Try scooting your butt towards the back of the seat while braking.
 

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Yes...like most have already said..."Forget you have a rear brake"

That panic habit will just get you hurt. I know the MSF course teaches folks to use that rear brake, but it's a bad thing until the very very last little bit of a full emergency stop.
 

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yes, it does get a little squirrelly under hard braking. no avoiding it really. using rear in this situation i found can make it worse. i dont know if harder springs up front prevent it from happening. i found the reverse, but hey, i can steer tons better in the corners.
 

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Use more front brake, less rear. It's a very light bike.
 

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wacky_woodchuck said:
Also check your rear sag... You may not have enough... causing the front wheel to lift ever so slightly from the ground....
That's what I'll blame my wheelies on next time! See, Officer, it's just that I can't get the rear sag just right and the front end just jumps up...

wacky_woodchuck said:
It happens to me on hard braking at times... especially when using the back brake...

Check your sag... go from there.
Your front end lifts under braking?
 

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I think he meant rear end

I think its grabbing too much front brake too soon or abruptly mostly as this will get rear lifting quicker and easier than if you applied the brakes more smoothly. I understand that sometimes sudden stops are needed but... even then if you load front smoothly as you progressively pull more brake quickly... it should be mangeable. Proper setup of suspension will of course help too.

as for totally forgetting rear brake... yes... if you can't modulate the rear then maybe forget it as it will cause problems but... if you ever get into a situation where a sudden stop is needed... that 10% of braking could be the difference between you face planting into a tail gate of a truck or stopping a few feet short of it and if you develop habit of not using it... you most likely will not use it when you really need it either. I suggest letting some air into rear brake line if it locks up to easy for you. I left a little air in my line plus had my rear rotor drilled for less weight and less braking power and now I hardly ever lock the rear but still get use out of it.
 

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Keep in mind that bikes can completely lift the rear wheel off the ground in hard breaking. Just remember you have exactly 0% rear braking then. I use the rear brake when coming to slow stops, but If Im jamming on the brakes, I squeeze the fronts enough to transfer weight and then just jam on them. When I touch the rear it just likes to lock up.
 

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when breaking hard, I can feel a huge difference when applying both the front and the rear brakes. I guess the biggest thing is just getting a feel for the bikes brakes and applying the front brake only for the initial front end dive, then come in with both the front and the rear to help you keep stopping. I think i stop much faster with both
 

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useful techniques

There are times when rear braking is not a good idea. On loose surfaces, for example, it doesn't do much good. In fact, neither front nor rear braking is easy to control on loose surfaces, but that's another story.

On dry pavement you should develop a feel for rear wheel braking. The other technique that is useful to learn is steering with the rear wheel locked up. Even if you modulate carefully you can and probably will occasionally lock the rear wheel. It is possible to control a rear wheel slide if you start slowly (preferably with an old rear tire you are getting ready to change anyway). It's a more useful technique than learning how to wheelie.
 

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i eluded to this issue in another thread and never got much feedback. i have been very displeased with the back brake since i got the bike... it is probably the only complaint i have. within a week of purchase the rear locked up under hard (not sudden, mind you) braking in a close call causing the ass end to swing out before catching traction again throwing me to the ground on the high side. some scratches on the pipe and a new right front turn signal... i chalked it up to not having ridden in a while. so almost a year later, i have learned to anticipate the bike doing this and have adjusted, but i don't remember any other bike i have owned being that touchy on the rear, and i have ridden some old crap in my day.

i know the front brake carries the bulk of the load and use it as such but i always thought it should be closer to a 70% front - 30% rear ratio.

being told to ignore the rear brake isn't good enough for me. if that's the case, why even put a brake pedal on the bike at all? is it just a given that the stock set up is bunk? i don't know who mentioned changing the fork oil but that was something i hadn't thought of as it applies to braking. from what i have read on suspension i should have changed that out anyway. at any rate, learning how the bike performs as far as braking goes has helped because i know i can't count on the rear end. but it would be nice to have that little extra just in case.
 

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I pulled up the MSF manual and was dismayed to read what they advocate for breaking technique. It's shockingly dangerous. Then I did a search and came up with a potential reason why the MSF course teaches front + rear braking stops.

Here is a bit of information regarding modern sport bikes and the old--very old-- rear brake rules that the MSF advocates. The article is pretty old, but still very much worth reading in full.

http://www.msgroup.org/TIP030.html

Many motorcycle instructors, from Part 1 up to Police Advanced, still quote the following old chestnut: you brake 75% Front and 25% Rear (on a dry road - 50%:50% in the wet).

This advice is also enshrined in Motorcycle Roadcraft and the IAM Group Handbook. So it's a pity that, nowadays, it is wrong.
Progress changes things.

The 75%:25% rule made its first appearance a LONG time ago. The early diagrams explaining it show drum braked Triumph Speed Twins, so it's not unfair to assume that the same 75%:25% rule has been around at least 25 or 30 years.

The old Speed Twins and their ilk had little in common with today's motorcycles. They had a twin leading shoe front brake of about 7" diameter [I can't find anyone who's old enough to be certain] operated by a bowden cable from a handbrake lever. The rear brake was single leading shoe, about 6" diameter, but operated by a sturdy 10" long footbrake lever, by a leg honed to muscular perfection by kick-starting the damn bike in the first place.

And the tires? They were no wider than the widest mountain bike tires of the 1990s, they were poorly designed even compared to the car tires of the day (some cars already had tubeless tires, but all motorcycle tires were high aspect ratio cross-plies). The usual tread pattern was ribbed front and block rear. And the all important contact patch was long and thin - not least because the wheels were 20" or more in diameter.
Summary: Rear does pretty much zero until you are down to 10 or so MPH in a full stop situation. Well, more then zero if you count in the odds of having a highside.
 

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epr194 said:
Summary: Rear does pretty much zero until you are down to 10 or so MPH in a full stop situation.  Well,  more then zero if you count in the odds of having a highside.
the rear brake is also useful during the first few moments of braking before weight has transferred to the front. so optimal emergency braking consists of starting with 50/50 front/rear braking then immediately begin reducing rear brake to 0% as weight transfers to the front; then leave the rear at 0% for most of the braking process, and perhaps reapply the rear just as you stop.

the problem is that while this technique is ideal, very few people actually master it (i haven't). so they go around using the rear brake incorrectly, which then decreases safety.
 
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