I posted on this before, but I haven't quiet figured it out yet.  When I break hard using both breaks my rear wheel starts to play side to side. It definitely isn't caused by me pressing on the rear break too hard/abruptly.  On the other hand, I start breaking with the clutch engaged, and I pull in the clutch at the last moment (when rpms get down below 3k), as opposed to clutch in then break.  Do you think this could cause the rear wheel to slip?  From your experience, when would one experience losing control of the rear wheel?

Thanks and have a good one

You are doing the correct thing with the clutch you should pull the clutch lever at the last second before you stop, it help keep the wheel turning. Are you sure you are not pressing on the brake too hard? The back break is very easy to lock with a disc brake. If you jump down the gears quickley this can also lock the back wheel.

The combination of engine braking and rear brake application could easily overwhelm rear tire traction.  Especially depending on the weight transfer caused by the soft GS springs.  In the other situation, braking simultaneously, the weight transfer will be more dramatic since the front brake will upset the chassis more than engine braking would.  It is amazing how little brake in this situation will lock up the rear.  I wouldn't count out too much/too fast brake application as a potential cause, as that really is the most likely problem.  If the rear starts to step out on you, and you release the rear brake, the bike will try to part ways with you, wether or not you get tossed depends on lots of factors, but it is better to avoid the situation all together.

Find an open & empty parking lot and do some braking with just the front brake...  Work on just the front brake for a while...  Do some quicker "emergency" and what not so find the limits and see how fast you really can stop the GS...  (Progressively add pressure to the front brake... Don't "snatch" it...  DON'T LOCK THE FRONT!!!)...  Once you're used to braking with only the front, work the rear brake back in...  Get them to work together...  Apply the same amount of pressure you were using while braking with only the front, but add a small amount of rear brake...  Then a little more...  And a little more...  

When I did that, I found that I wasn't using my front brakes very much...  I thought I was applying the same amount of force to both, but I was heavily favoring the rear brake.  I was ruining my braking potential since 70% of your braking is in the front and 30% is in the back...

You can also see what it's like to brake with only the back...  You can test the limits of "Hard Braking" with the front and the back alone without locking the tires...  When you add them back together (without locking either tire), you'll be able to stop on a dime and have 8 cents change.


If your rear wheel is locking under light pressure, there's something wrong with the rear brake system...  What it is, I don't know.

I see, seems like the bet is on overapplying the lever.  I am going to experiment / pay more attention to the rear break again next time.  I am definitely applying it smoothly, and I am not downshifting rapidly.  The wheel doesn't lock right away, it happens almost just before a stop.  i.e. the bike shaves off speed quickly (because I am trying to break fast) and stays in control until it's about to stop, and that's when I start feeling the rear wheel wiggle left 'n right.

Might I suggest a copy of Proficient Motorcycling by Dave Hough?  He discusses proper braking technique as well as many other things that you should know to be a better motorcyclist beyond what the MSF BRC teaches.  If you haven't taken the BRC, then that's the first thing you should do.  You can even support the site by buying the book through the link on this page: http://gstwin.com/gstwin_donation.htm

Quote from: GSinUS on February 22, 2006, 05:54:17 PM
I see, seems like the bet is on overapplying the lever.  I am going to experiment / pay more attention to the rear break again next time.  I am definitely applying it smoothly, and I am not downshifting rapidly.  The wheel doesn't lock right away, it happens almost just before a stop.  i.e. the bike shaves off speed quickly (because I am trying to break fast) and stays in control until it's about to stop, and that's when I start feeling the rear wheel wiggle left 'n right.

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Maybe another perspective will help you understand why this is happening to you... If you understand that weight shifts forward during front wheel braking (think: nose-dive), you'll realize that the rear end of the motorcycle gets progressively lighter as you use the front brake. That actually makes it easier to lock the rear wheel, especially when you're using the front brake hard (think: panic stop).

The solution to the problem you've described is to SLIGHTLY release pressure on the rear brake as the bike slows down. Motorcycles with anti-lock brakes automatically modulate the line pressure during braking; we of the GS persuasion need to do it manually. The lighter the rear end becomes during braking (such as in a panic stop), the less pressure is required to lock or skid/fishtail the rear wheel.

A properly used rear brake can save you from falling if you lock the front, because draging rear will stabilize the bike.