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Discussion Starter · #1 ·
I was riding to work out in Maple Ridge today, and shockingly, had the oh-so-typical cager turn left in front of me just as I was entering the intersection. I braked hard, but not excessively, and narrowly missed the guy. I noticed, however, that it felt like my back end was sliding sideways on it's way to becoming almost even with the front. As soon as the guy was out of my path, I let off the brakes and accellerated, which straightened me out. Boy, was I ever pissed. I talked to a guy later who was behind me when it happened and he commented on how close he thought I'd come to getting destroyed.

My question is: Why did the back end slide out like that? As far as I know I firmly and evenly applied increasing pressure to both brakes. Options I have entertained are that I loaded the front when braking thereby lightening the back end and reducing traction or that I did lock up the back. Do I need a new rear tire, perhaps?

I've experienced the sensation on my last bike, and occasionally I do feel like when stopping the back is sliding sideways, but only minutely, and I think it might be psychological (thought I felt it much of the way home tonight at midnight, though the roads were kind of slick).

One peculiar thing is that it always seems to be going to the right-hand side. Is there any way that it could be my body position during harder braking that disrupts the bike?

Anyway, any thoughts or input you might have are welcome as I'm really having a hard time figuring this out.
 

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Good job dodging the cager.

I'm guessing you must have locked up the rear, it shouldn't have slid otherwise. I've had my back end slide around a little on uneven pavement when locked, even going in a straight line.
 

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The back end slid out because you locked the rear brakes and there is never enough weight over the rear tire when you are riding alone. It doesn't really matter if your tire is old because I slid out the rear tire of my bike before when it was new.

You really need to have a much more lighter touch on the rear brake than the front. It's 70% front brakes and 30% back brakes. Some people don't even bother using the rear brake but that's a debate for another thread. And some people use only the rear brake when moving at slow (walking) speeds.

The best thing to do is to find an empty parking lot or road and practice your emergency stops. Start off slowly and then try to stop harder and harder as you become more comfortable.

Good to hear you got out of this situation...
 

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when braking that hard the rear brake seems almost useless.. my rear end slides out all the time.. I've pretty much givin up on it. the only time I use my rear brake is at slow speeds or dirty/gravel roads to prevent my front end from washing out.
 

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.Z said:
IWhy did the back end slide out like that? As far as I know I firmly and evenly applied increasing pressure to both brakes.
As you smoothly apply pressure to your front brake the weight of the bike shifts towards the front (the nose of the bike dips as well), increasing the load on the front tire and decreasing the load on the rear. The rear is easier to "lock-up" as a result.

It is great to see that you peformed this smooth braking - it is a good technique to practice - load shifting in a parking lot. By smoothly applying the front brake (not grabbing the brake) your front tire can provide a tremendous amount of braking power. The hard thing is to control your muscles and not grab the front brake in an emergency...
 

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I rarely use my rear brake on the street any more at all. I only use it on hills and at lights to prevent rolling.
 

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The previous posts elegantly explained the rear brake lock up, so I won't comment on that.
Also, if it's a "left turn," situation, it may be in an intersection surface that may have contributed to the rear brake lock up.
Crosswalk paintings, oil deposits make for a more slippery asphalt surface and any one of t hese could have initiated the loss of traction.
So while your pressure on the rear brake pedal may have been appropriate for the circumstances, the road surface may have conspired against you.

Nice save though, and I'm impressed to see that instead of cursing the cager, you're treating this as a learning experience.
 

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The back end sliding out and "becoming almost even with the front", that is probably caused by your body position. But it could have also been the slant of the road, etc, there's so many different factors. If you've felt it happen before and you can remember it, I'd go and practice. We don't have to do emergency procedures too often, so it's a good idea to practice them once and a while to make sure you still remember!

;D
 

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Sounds like you were backing it in (or around as the case may be).

When you're very hard on the front brake it doesn't take much to lock the rear. You don't even really need to lock it up for it to move. Just break traction initially and then it starts to wander around on it's own.

Now go buy a motard, and get used to doing it every lap.
 

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I know they teach you to use both brakes evenly but in hard braking situations this is NOT the thing to do. As you've seen in the posts above the weight transfers to the front wheel and unloads the rear leading to locking up and drifting around.

In extreme cases the rear won't have ANY weight on it at all and ANY use of the rear brake will lock it up and produce this sort of sliding. At this point even the engine's compression braking can cause a little bit of drifing around.

Oddly enough the proper way to brake is even front and rear brake for most casual stops but as the need for harder braking comes into play you need to pull more with the fingers and press less with the foot up to the point where at full racing or emergency braking efforts it should be ALL front and no rear brake at all. (using the rear to "back 'er in" is a special case and has nothing to do with slowing down)

Not an easy thing to master. Goes against the grain of "pull and press hard to stop hard" doesn't it? But until you get the hang of it you'll find you get this sort of rear end locking up in harder stopping situations. It's one reason many of us don't use the rear brake unless conditions are such that it's the better option. LIke in rain or other slippery situations. In those cases a balanced use of front and rear will provide the shortest stopping distance and most control. It also has the advantage of being able to use the rear if it locks as a sign of traction or lack of traction.

So why do the schools teach use both together and pull&press together? Most likely because the know that most folks are afraid of the front brake and won't pull on it hard enough to produce the sort of dry clean road effort that it takes to lift the back wheel. So for 98% of the time balanced use of both is the best way.

THis is where something like the WCSS ART course or other advanced riding courses come into play. There you can learn how to use the bike more effectively both for going around corners as well as learning just how darn hard the bike can actually stop when it's done right.
 

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Discussion Starter · #11 ·
Thanks everyone for the responses!

I've read before the varying views on rear braking, but never really connected the fact that the back end is so light (in single-rider situations) with what I percieve as the instability of the back end. I'm definitely going to go out and practice a modified hard braking technique; after all, a little extra practice can never be a bad thing, especially given the opportunity to correct and modify repeatedly.
 

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same thing happened to me today with the sliding out but i used to ride dirt so i dont get freaked out like some do...im definately gunno have to practice my hard braking too in a parking lot
 

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It's not that the back end is light in single rider situations. It's got the weight on it that it SHOULD have. But it's the action of using the front that takes weight off the rear.

Try braking with rear only a few times. Try to get a feel for how much foot pressure results in a lockup. Then use the front brake semi hard and while you're stopping press on the foot until it locks. You'll find that it's a LOT less press to reach lockup while the front is on.

No one will ever get the balance just right to be able to use the rear without locking up in all cases. And in a panic stop you'll always press too hard on the rear. The adrenaline coursing through your veins will see to that. This is why some of us have just chosen to switch to using the front only or only using the rear conciously when conditions require it.

I know that for myself I probably do 75 or 80% of my stopping with the front brake only.
 
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