Rear Braking

[joey90]

Does anyone have any info on rear braking techniques as to when , where and how to use it ?
I read a few articles that say many top racers use it, but in the Kieth Code book it says NOT to use it . please let me know what your opinion is. Thanks

[Woofentino Pugrossi]

Not really.:D Mainly in the paddock at Blackhawk Farms gravel road. ;D

[MJFRacing]

Not really.:D Mainly in the paddock at Blackhawk Farms gravel road. ;D

Ditto!  :D

I think there are some advanced techniques that maybe some pro/expert level guys use but out on the track I've never used or needed rear brakes. Well, there was that time I ran off into the grass. . . but I said on the track!   ;D

[cardzilla]

You can use it mid-corner to tighten a line.  Also, if you are deep into a corner too hot it is the safest way to bleed a few MPH.  That said, I can't do it with my foot, I need a thumb brake... which is far as I can tell is illegal in supersport so I don't use it.  I don't think it is worth the attention $ to worry about it unless you are MotoGP level talentwise, but if you did, I'd suggest the thumb brake... I have no idea how these guys use the foot brake accurately.

[james-redsv]

Just use it only if you run off the track and are in the grass or gravel.  ;D

[Super Dave]

Lots of personal preference here...

There are some real opportunities here.

Technique is the trick.  How much time do you have to work on it, and do you have a back ground that might have utilized it before?

Dirt trackers adapt to it really well.  But do they sacrifice some entry speed?  Jason Pridmore does really well with the front.  So does old Miguel DuHammel.  I've watched some traditional road racers try it for style, but sacrifice some corner entry speed.

Way leaned over, yeah, it can work well as you have a good deal of weight on the rear wheel by then...but do you have the ground clearance?

Are you able to use the front brake mid corner?  

[stumpy]

You can also use the clutch to get engine to slow down the back tire too. I can kinda get it to come out a couple of inches which feels like a couple of feet. I can definetily see where it could be usefull and it looks cool 8) I will be working on it... It's also unlocking the door for a nasty high side too.



Stumpy

[motomadness]

I've been watching AMA videos to capture a window where I think I'd like to try it.  If you've got some tapes of Road Atlanta, check out Mladin mid-corner in T10.  He uses the rear every time.  His technique appears to be after turn initiation before approaching full lean.  He maintain pressure until after he begins picking up the bike on the exit.  Some old WSBK races also have some visible usage.

On the Miguel thing, don't forget he uses a thumb brake also, following a leg injury years back.  Next time at Road America, get a good look at it.

[motomadness]

Also, GP Tech LLC. has a few thumb brake applications from Supermotard to SBK, etc.  In the smoto version, the master cylinder is setup up to lock the rear, but on the roadrace version, it just scrubs a little speed.  I think you can achieve a similar roadrace version with the foot master cylinder by putting a little air in the rear brake line.  It's not the safest setup, but if you are going to practice, you might as well increase your safety margin a little.  That being said, keep the rubber lines on as well for a little more slop.

[chris_chops]

FIND A FLATRACKER AND BEAT IT OUT OF HIM!!!

or maybe check this out

Get a dirtbike and ride it a lot.  With enough corner speed you can get the bike to come around.  If you have good throttle control you won't highside yourself while practicing.   Eventually, you can hone a technique in which you scrub speed off with the rear while getting the bike pointed in the direction of a late apex exit out of the turn.  Up by stumpy are some of the best dirt trails I have ever been on.  Miles and miles of practice on different dirt and different roads.
      After a good rain, some of these roads provide huge amounts of grip that aren't quite like road racing but they are enough to load the suspension up.
      I took what I learned and applied it to roadracing and here is what I found:  YOU HAVE TO BE GOING FAST AS HELL TO GET 'BACKING IT IN' TO WORK FOR YOU.  REALLY, REALLY FAST.
      It's all about not having grip in the rear going in to the turn.  This is the 'backing it in' part and almost any of us can do this.  This is the easy part.
      The problem is know you have to gather it in without a jerky transistion that upsets the bike, crosses it up, and spits you off into the distance.
     The thing you don't see on the speedtv is the guys that can do it have the front sliding a bit too.  This helps the whole process and helps quell the jerkiness.  The jerkiness that hurts real bad.  
     Now that you are comfortable at the ragged edge of control with front and rear sliding, you use your legs and the bars and a little bit of your butt to steer it and rocket out of the corner.  Using throttle control and slide control together in harmony while searching for grip and staying on the racing line.  Super easy, dude. ;D ;D

And no, I rarely have the balls to try this or much lesss pull it off on a roadrace track.  It mostly happens by accident when I am going a little bit faster than I should be into a corner.  Rushing it a bit.  With that said, on a dirtbike I am quite good at it with a ton of practice and SEVERAL FULL ON HIGHSIDES.  OUCH!!!

This is just my opinions.  Don't beat me up too bad if you think I'm all wrong.
          

[pmoravek]

I had a guy at one of the schools tell me the funniest thing.
"You can only get about %10 effectiveness out of using your rear brake...but I'll take that 10%"

That being said....I don't touch the back brake unless I'm in the grass or at tech.  ;D

[Super Dave]

I had a guy at one of the schools tell me the funniest thing.
"You can only get about %10 effectiveness out of using your rear brake...but I'll take that 10%"

'bout right...

A motorcycle with a 50/50 weight bias...the rear wheel will have about 8.5% braking force straight up and down...with not front brake added.  Leaned over, the bike will distribute a little more weight to the rear as the traction gets used in the form of cornering force...You'll get more rear braking force.

[motomadness]

Here's a thought:

When you use the rear brake at the start of turn initiation and you are going really fast, using the rear brake will extend the shock, which will further reduce the trail and tighten the steering head angle, causing the bike to turn in more.  This will also increase rear traction at the same time through the shock's release of energy.

Issues:
Your shock needs to be setup for rear braking.  The rebound damping has to suit the turn in effect, and you've got to have enough rider's sag/free sag to allow shock movement.  I don't think this is a setup to get the backend far out of line with the bike because this is during turn initiation all the way through the apex and then some.

Of course I've never tried it before, but this year I'm going to put a thumb brake on my TTR and practice.  After I assemble it just come by my pit and I'll let you try it out.

[Super Dave]

Here's a thought:

When you use the rear brake at the start of turn initiation and you are going really fast, using the rear brake will extend the shock, which will further reduce the trail and tighten the steering head angle, causing the bike to turn in more.  This will also increase rear traction at the same time through the shock's release of energy.

Light ground here.

Turning in will put more weight on the rear shock as you're going from traction forces being used for braking force (weight forward) to cornering force (more distributed weight)...

[motomadness]

I agree.  I think the key might be the timing of your braking, timing of the turn-in and how much inertia (momentum) the bike still has to pitch the bike forward.  My thought is that if the wheels are still in line, the only way to turn the bike in more is to shorten the wheelbase / reduce your trail - not easy to do, but there's no other way.

Counter steering you say.  Maybe, but the effect might still be a momentary reduction in wheelbase, just more stabily controlled.

[Super Dave]

I My thought is that if the wheels are still in line, the only way to turn the bike in more is to shorten the wheelbase / reduce your trail - not easy to do, but there's no other way..

If you don't have the wheels in line, the lean angle of the rear tirw will be more than the lean angle of the front, thus, your effective lean angle will be more than the front.

When you will use the brake depends upon when you need to slow down to do what you need to do.  If you're going really fast and you need to go slow in the corner, you'll be using the brake before turn in.  If you're going into a fast corner, you might not initiate the brake until in the corner.  

Regardless, as you begin to turn, more weight will be on the back wheel and you will have more braking force available with the bike leaning over when compared to going straight on a motorcycle with a 50/50 weight bias.

[motomadness]

Regardless, as you begin to turn, more weight will be on the back wheel and you will have more braking force available with the bike leaning over when compared to going straight on a motorcycle with a 50/50 weight bias.

Good point.  That's kind of what I was getting at - taking advantage of the weight shift to use the rear brake in this technique.

[Rick Beggs]

man i hate to have an opinion so different than everyone else, but
the rear brake is required, so why not use it?
ever endo on the front brakes? i use the rear brake as soon as i let off the gas, on fast straights, to lower the rearend, 2 inches lower is 2 inches  more before it endos. , i hardly ever use it when turning, and it has got to help slow it down. i use the clutch a lot when initiating the turn to turn in faster

[Super Dave]

Hate to be a nay-sayer...

But regardless of which brake you use, the weight transfers forward.

One might be able to settle the suspension with the rear brake, if you're a violent front braker.  Really depends upon technique.

If you had an old bike with particular chassis geometry from about the early 70's, when you let off the gas and got on the brakes, yeah the rear would collapse, but that is a function more of the swingarm angle and the swingarm pivot location.  

One cannot slow down the bike with the rear like one would with the front.

If one is using 90% braking force with the front brake and the rear brake is added, it will still transfer weight forward.