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Re: Rear Wheel Lock-up
Posted: Thu Aug 10, 2006 10:43 am
by Oilhead
beemerphile wrote:
I think we mostly do. It is just in the definition of "proper".
This reminded me of when I took the MSF's ERC course. I took the course a few years ago as it came as an compimentary reimbursement for buying a new Honda.
There were two instructors and they were the total opposites when it came regarding proper. During the quick emergency stop drill, I did a stoppie(only a foot or so off the ground, nothing in the territory of stupidity) and stopped on a dime. In far shorter distance than anyone in the class. The first instructor told me that it was an awesome display of brake control and commended me.
Then as they did with all the drills, our group rotated and I got the second instructor. I did the same thing. This instructor with his face turning red screamed at me for not being able to control my bike. This is not true as I had full control of the bike at all time. He said that I locked up the front momentarily and I am lucky that I did not crash.
Anyway, I see where you are coming from Beemerphile. Yes in 95% of the cases, the rear brakes probably do more harm than good, hence your advice. Howeve even if you are never going to use it, one should be totally familiar with the full potential of their rear brakes. One should always be conditioned to use the front/back in ways that are ideal for the situation The funny thing is, one time, I had to slam on the brakes on the highway as the guy in front of me slammed on his brakes as he realized he will miss his exit. I instinctively initially slammed on the front brakes only and then both front and rear once the bike slowed down somewhat(all this is of course in a fraction of a second).
Posted: Thu Aug 10, 2006 10:47 am
by Oilhead
sjbmw wrote:I try and use my rear brakes often, to increase the lifespan of the front.
I agree with that too but the front seems to last way longer than the rear on my Roadster for some reason. I have 18K on mine and the front seems to be almost new while the rears are about 1/3 left.
Posted: Thu Aug 10, 2006 12:15 pm
by beemerphile
Oilhead wrote:sjbmw wrote:I try and use my rear brakes often, to increase the lifespan of the front.
I agree with that too but the front seems to last way longer than the rear on my Roadster for some reason. I have 18K on mine and the front seems to be almost new while the rears are about 1/3 left.
This is a common problem with the GS and R rear brakes. Chances are that the pins are not free and you are running with more friction than you should be. It may be getting very hot as well. If you will disassemble the caliper and clean / lubricate the pins and reassemble it you ought to be able to get back to normal life. I have never replaced a set of rear pads except to get the factory OEM trash off of them.
Re: Rear Wheel Lock-up
Posted: Thu Aug 10, 2006 12:25 pm
by beemerphile
Oilhead wrote:He said that I locked up the front momentarily and I am lucky that I did not crash.

Locking the front wheel momentarily is not a problem. I have found that when you lock up the front wheel you have almost exactly one second before the bike falls over. What is amazing to me is that the 1 second has been repeatable on a number of bikes from ST1100 Hondas to any of my previous (or current) BMW's and with a number of different traction levels from wet or gravel to dry road.
One second is plenty of time to get off the brakes and reapply. Locking the front brake is not so scary as long as you know how much time you have to correct. All of this assumes that you are upright, of course.
Lee
Re: Rear Wheel Lock-up
Posted: Thu Aug 10, 2006 5:17 pm
by Oilhead
beemerphile wrote:
Locking the front wheel momentarily is not a problem. I have found that when you lock up the front wheel you have almost exactly one second before the bike falls over. What is amazing to me is that the 1 second has been repeatable on a number of bikes from ST1100 Hondas to any of my previous (or current) BMW's and with a number of different traction levels from wet or gravel to dry road.
One second is plenty of time to get off the brakes and reapply. Locking the front brake is not so scary as long as you know how much time you have to correct. All of this assumes that you are upright, of course.
Lee
Exactly!
A lot of riders don't realize that they have that that window of opportunity to correct front brake lockup. I learned this years ago from riding in the dirt. Rear brake lockup, you don't have that window. If you release a locked up rear brake at high speeds, you will highside and crash(and no this is NOT from personal experience....

).
Posted: Thu Aug 10, 2006 5:43 pm
by DJ Downunder
A lot of riders don't realize that they have that that window of opportunity to correct front brake lockup. I learned this years ago from riding in the dirt. Rear brake lockup, you don't have that window. If you release a locked up rear brake at high speeds, you will highside and crash
I find that odd..I would have though the other way around.
I've ridden dirt for years and rear lockups were commonplace.
I guess it depends on how high the speed is and if you straighten the bike up before releasing the rear brake.
DJ
Posted: Thu Aug 10, 2006 6:50 pm
by Oilhead
DJ Downunder wrote:
I find that odd..I would have though the other way around.
I've ridden dirt for years and rear lockups were commonplace.
I guess it depends on how high the speed is and if you straighten the bike up before releasing the rear brake.
DJ
Sorry DJ I should have been more clear.
What I am saying is pertaining to street riding...
If one locks up the front brakes, you lose 100% control. However, as Beemerphile stated, there is a small window of opportunity to be able to correct it by releasing the brake lever. I feel a lot of riders don't realize this, seeing how many crashes are caused by the front brake locking up and the bike careening out of control.
If one locks up the rear brakes (and I'm not talking about slow speed or on dirt where you do it on purpose) at a relatively high speed, you do retain some control. Now in total contrast to front brake lockup, one must brace themselves and control the skid. If they release the brakes, the bike will suddenly straighten up by following the front wheel's path and you will high side and crash.
Posted: Fri Aug 11, 2006 5:35 am
by riceburner
beemerphile wrote:Oilhead wrote:sjbmw wrote:I try and use my rear brakes often, to increase the lifespan of the front.
I agree with that too but the front seems to last way longer than the rear on my Roadster for some reason. I have 18K on mine and the front seems to be almost new while the rears are about 1/3 left.
This is a common problem with the GS and R rear brakes. Chances are that the pins are not free and you are running with more friction than you should be. It may be getting very hot as well. If you will disassemble the caliper and clean / lubricate the pins and reassemble it you ought to be able to get back to normal life. I have never replaced a set of rear pads except to get the factory OEM trash off of them.
Linked brakes??
I actually favour the OEM pads - they're thicker than most aftermarket parts - up to twice as thick as some.
Posted: Fri Aug 11, 2006 6:58 am
by beemerphile
riceburner wrote:Linked brakes??
Not sure of your question...
I actually favour the OEM pads - they're thicker than most aftermarket parts - up to twice as thick as some.
My problem with BMW OEM pads is that they eat brake rotors. I replace them with Galfers Green on front and Galfers black on the rear. The Galfer pads don't last as long as the OEM's but the disks (which are more espensive) last longer and the bike stops better. At each change, I disassemble the calipers and clean and re-lubricate the pins.
Posted: Fri Aug 11, 2006 7:18 am
by beemerphile
DJ Downunder wrote:I guess it depends on how high the speed is and if you straighten the bike up before releasing the rear brake.
On a dry street, the traction you regain when you release a rear lock-up is much more drastic than what you get in dirt. A rear lock-up on a wet street can react somewhat like one in the dirt.. With limited traction, there is often not enough traction to throw you over the bike. On a dry street with good traction though it goes to hell in an instant when you release the brakes while out-of-line.
You are on to a workable strategy though. If the bike is wagging its tail both ways you can release the brakes when the back end goes through center. The reason rear skids are so deadly though, is that you probably got in that situation as a response to an emergency. Therefore you don't have time to wag the bike back to center or ride the skid out. The skid might end in the face of the proverbial Buick. Often, unfortunately, your goose is cooked at this point because your first avoidance technique has only caused you to lose directional control over the motorcyle and you don't have time to fix the mess and execute a plan B. The downside of rear lock-up in an emergency is so severe that I will take major steps to avoid its occurance - to the point of not using the rear brake in emergency stops. Your Plan A needs to work.
Posted: Mon Aug 14, 2006 4:37 pm
by chris
Well today I tried ( under controlled conditions on straight dry flat tarmac) to lock up the rear wheel on purpose but couldn't get it to lock no matter how hard I hit it. I'm also used to dirt riding and sliding and locking brakes in the loose stuff but it didn't want to play. Seems the rear on its own has plenty of grip and no I'm not a pie smuggler, 12st wet through!

Lucked out twice
Posted: Mon Aug 14, 2006 6:01 pm
by ramblinrod
Reading through the posts on this topic reminds me how lucky I have been on 2 occasions. Both times I got on the brakes harder than I intended when I was about to miss a turn. Both times I locked the rear brake and even though I know better mentally, immeadiately released the rear brake. That put me into a wobble that I was able to straighten out and didn't go down. I have only locked the front brake on gravel and was able to get off it quick enough not to go down. In braking practice on pavement I always chicken out before the front wheel locks. Need to work on that some more as it would be good to know where the limit is. Of course from my past experience, when the Buick pulls out in front of me I will probably lock both brakes and go down.
Rod
Posted: Tue Aug 15, 2006 4:55 am
by riceburner
beemerphile wrote:riceburner wrote:Linked brakes??
Not sure of your question...
Sorry - if the bike has linked brakes you can eat the rears a lot quicker than you'd think.
beemerphile wrote:
I actually favour the OEM pads - they're thicker than most aftermarket parts - up to twice as thick as some.
My problem with BMW OEM pads is that they eat brake rotors. I replace them with Galfers Green on front and Galfers black on the rear. The Galfer pads don't last as long as the OEM's but the disks (which are more espensive) last longer and the bike stops better. At each change, I disassemble the calipers and clean and re-lubricate the pins.
I do the same and it helps with keeping the callipers clean, but prefer the OEM because I think the feel is better and the stopping is stronger, imho. Tried 1 set of EBC HH pads, which I always preferred on my ZXR400 but they didn't suit the BM at all.
Posted: Tue Aug 15, 2006 4:58 am
by riceburner
chris wrote:Well today I tried ( under controlled conditions on straight dry flat tarmac) to lock up the rear wheel on purpose but couldn't get it to lock no matter how hard I hit it. I'm also used to dirt riding and sliding and locking brakes in the loose stuff but it didn't want to play. Seems the rear on its own has plenty of grip and no I'm not a pie smuggler, 12st wet through!

You're not trying hard enough or the brakes need bleeding.
Posted: Wed Aug 16, 2006 2:13 am
by chris
riceburner wrote:chris wrote:Well today I tried ( under controlled conditions on straight dry flat tarmac) to lock up the rear wheel on purpose but couldn't get it to lock no matter how hard I hit it. I'm also used to dirt riding and sliding and locking brakes in the loose stuff but it didn't want to play. Seems the rear on its own has plenty of grip and no I'm not a pie smuggler, 12st wet through!

You're not trying hard enough or the brakes need bleeding.
Found a bit smoother tarmac this morning and got a nice squeal and a black line for not much effort...hmmm