Sorry to ask this question if this has been already discussed before. I did a quick search on this and did not find convincing answers to this question... I have some reasonable experience  riding motor bikes. For optimum braking I tend to use the front brakes:back brakes in something like a 70:30 ratio.

When I started out riding motorbikes I have had some terrible times gripping the back brake, the bike would slide off sidewards. I have gone through some scary moments. I have had to learn it the hard way though  . The problem is I still cannot convince myself why applying a lot of the back brakes is dangerous. I would be glad if someone can shed some light on their experiences and more importantly reason why?

Thanks       

It depends totally on the rider. Some people tell you 70/30 and some tell you to never use the rear brake. I personally go 50/50 because I have more control in a corner with my rear brake (somewhat trail braking).

Dangerous because like you said, it's easy to lock up the rear.  If a rider were to lock up the rear, slide sideways, then release the the rear brake, a high-side is very likely.

When braking, weight shifts to the front of the bike, this is why more braking can/should be done for optimum braking.  If you're really hard on the brakes, almost no weight remains on the rear tire.  This is why it's easy to lock up the rear.  And why it is recommended to to more braking with the front, where there is more traction.

QuoteDangerous because like you said, it's easy to lock up the rear.  If a rider were to lock up the rear, slide sideways, then release the the rear brake, a high-side is very likely.

+10¹⁰⁰⁰
This results since the loss of traction at the rear allows the rear end to get out of alignment in respect to the front.  Like motf said, if the brake is then released it allows the rear wheel to regain traction which causes the rear to snap back in line with the front which causes a high chance of a high-side.  Now this not saying if you do release the rear brake instead of keeping it locked that you will be in a terrible crash the likes of which satan himself couldn't dream up  just that the danger does exist and the best route is to keep that rear sliding.

I use my rear brake all the time except running hard in curves.I am very light on the rear brake.I have locked up the rear several times because I'm using EBC HH pads front and rear.I have even slid both the front and rear in the rain.I've never hit the ground but I have scared the pooh out of myself.

You need practice man, lots of practice. You need an empty parking lot, a friend with a cellphone (to call for help if you crash, no really, i mean this) and lots of time to practice.

Do a few slow speed E stops with just the rear at not more than 20 MPH, IN A STRAIGHT LINE.

Get used to the feel of the rear locking, then use the front and rear, but don't try to lock either. LOCKING THE FRONT WILL PUT YOU DOWN HARD AND HURT ! Locking the rear in a straight line will only stabilize the bike. Do not release the rear in a slide. Slide till stopped.

Once you feel confident with SLOW use of the rear, use it in figure 8's and u-turns. Just drag it a little. Until you're proficient with the rear brake, you shouldn't be on the road at all. If you fear the rear, do not ride in traffic. At all.

Go watch this guys videos. All of em. http://www.youtube.com/watch?v=iMgU44UwByY

Practice practice practice, but please do not ride in any traffic until you can use both brakes proficiently.

+1 on the 70:30 ratio to front rear or even 75:25

The rear brake helps stabilize the rear end of the bike when breaking.  The harder the braking the more the roll of the rear brake plays.  When braking hard from say 100mph the front will tend do dive steeply causing the rear to come up (yes we all know this).  By using the rear brake at either 20 or 25% ratio the bike will not dive as much and will be much more stable and will reduce the rear end fish tailing left and right.  If the rear does lock it is no big deal because it will lock and stay straight.  Applying the rear brake increases the footprint of the tyre on the road to give max traction for accelerating or breaking.

I have spent a great deal of time on race tracks when I was younger where learning to brake properly meant gaining or losing a position, taking a corner perfectly or ending up in the sand trap, OR pulling up in time or T-boning that wanker that just pulled out of the side street without looking.

Let's get serious people if the rear brake was not needed it would not be put on the bike in the first place

Whoever has the theory that the rear brake does not need to be used when braking has rocks in their head and needs to do a riders course to learn how to brake properly.

Hope this helps a little. Remember to practice practice practice

I laid down a gorgeous perfectly straight line of rubber from my rear tire the last time I did parking lot emergency stop practice (with a buddy with a cell phone standing by), doing one of my fastest yet emergency stops in a perfectly controlled straight line on a beautifully behaved GS. it was about 20 feet long. I was really impressed with her stability. But I worked up to it with both brakes over lots of previous practice sessions. I need to have that reflex and also have an idea of what my stopping distance is now at various speeds and what it could be with more practice. My bud and I also do tons of circles, 8s, and use the parking space lines to practice tight low speed turns using a lightly dragging rear brake for added control and stability, with turning within two spaces as the goal. 

It takes practice practice practice like ohgood says. 08GSSteve is right too. I had a lot of involuntary practice on the street with my last bike, an old dual sport, until I got her new street tires and dumped the crappy knobbies. But I learned how to drive skids in a car and a bicycle years ago, and a motorcycle is similar in process; keep the front going straight and let 'er back end slide if it happens. On the old moto I ended up at a quick red light stop once with the rear end over to my left about a foot and a half. But perfectly upright and balanced after a long skid. Lousy rear drum brakes probably helped there, because I was at full on brake front and back. The back end was always skidding because of the knobbies. I don't miss the bike. 

I also trail brake, mostly into deep, steep tight blind turns which can be difficult to set up for; sometimes it's that or off the other side, but trail braking too certainly has a place in my skill set, on which I am always working.

Use all three brakes all the time; front, rear, and engine.   

manofthefield: Now that seems like a valid reason. Weight shifting up front, and the back end losing weight causing the skid.

ben2go: "I use my rear brake all the time except running hard in curves." I hope you are not kidding me on that ? 

ohgood: thanks for the link. I did learn a lot especially from the stoppies lol 

08GSSteve: "Let's get serious people if the rear brake was not needed it would not be put on the bike in the first place" - Now that was some serious penny for thought! 

Teek: so "practice, practice" is going to be my mantra now! I am going out to find an empty parking lot now. I have purchased new gear now, will come in handy just in case.

gsJack: engine braking is some new technique that I have picked up recently. Running one gear down helped me a lot in curves during a recent twisty ride.

Thanks all for voicing your opinions. I appreciate the response.

Quote from: ohgood on May 30, 2008, 07:42:33 PM

Go watch this guys videos. All of em. http://www.youtube.com/watch?v=iMgU44UwByY

Practice practice practice, but please do not ride in any traffic until you can use both brakes proficiently.

Hey Ohgood, great vids. Thanks a lot for the link. Really important stuff