Skating During Hard Braking

[tweek]

While watching motorcycle races the past few months I’ve noticed that when the rider is coming in to a corner and braking hard the rear end looks like it is skating back and forth. I know that you can lift the rear end using the front brake, but is this something you really want to do? Is it hard to control? Are the riders aware of it? Is it a good thing to have the back end loose as you setup to turn?

 

It looks really cool on TV but it also looks like it might be a tad scary to be riding a bike. In the MSF class I took the emphasized that sliding the rear is bad. These maniacs seem to do it constantly. How do they control it without highsiding once every lap?

 

I know this is a lot of questions, but I’ve got a lot to learn.

[harnois]

There are a couple different things I see happening with the rear end of the bike during braking.

 

1. The rear end shakes back and forth. Sometimes this gets quite violent.

 

2. The racers smoothly drift the rear wheel towards the outside of the turn they are approaching under hard braking. This is also called "backing it in."

 

Which one are you asking about?

[tweek]

I think I'm mostly talking about backing it in. They look pretty smooth doing it, but it still sorta freaks me out seeing it. You only got to wheels, this isnt Initial-D or some other drifting competition .

[harnois]

I think I'm mostly talking about backing it in. They look pretty smooth doing it, but it still sorta freaks me out seeing it. You only got to wheels, this isnt Initial-D or some other drifting competition .

 

I was watching a race on SPEED a few years ago and I think one of the racers was injured and therefore was sitting in as one of the commentators. I think it was Aron Yates but not sure. The other commentator didn't seem to know a damn thing about motorcycles. Anyway the commentator noticed this sliding and asked the racer about it. It went something like this:

 

commentator: "so are the racers using the rear brake to slide the rear wheel into the turn like that and why are they doing that?"

 

racer: "No, you don't use the rear brake on a street bike. Ya don't really even try to make it slide like that but sometimes it just happens and you ride it out."

 

Of course that is one racers opinion. Some racers I imagine do intentionally make it happen.

 

My understanding of it is that it happens as a result of being hard on the front brake, which takes all the downforce off the rear wheel. Then the downshifting provides just enough resistence at the rear wheel that it drifts out a bit.

 

I was watching another race recently where they showed an onboard camera shot. The rider in front of the camera bike backed it in and couldn't get it resettled in time to make the turn and ended up going just a little bit wide, and lost 1 or 2 positions as a result. One of the commentators who was obviously an ex-racer, said, "that is the problem with backing it in like that."

 

I am not enough of a badass to actually do this maneuver, so don't listen to anything I say.

[bellevuetlr]

after reading your first statement "While watching motorcycle races the past few months I’ve noticed that when the rider is coming in to a corner and braking hard the rear end looks like it is skating back and forth", i don't think you are talking about backing it in. i think its just rear coming loose caused by too much weight on the front. when backin it in, the rear only goes one way and it is to the outside of the turn. but eventually, the rear tire becoming loose on entry (sliding left to right) will result into what we call backin it in.

 

just wanted to clarify.

[marcus]

I have done it a few times, where I will be braking hard and upright into a corner, with very minimal rear brake "bias". Once I shifted down it locked up and started swaying side to side. This was also with a rev match and stock slipper clutch. Maybe not a perfect down shift... It can also happen without shifting and a bit more rear brake but the engines still running.

 

I also ride an MX bike and well you have to steer it with the brake and throttle so its never a big deal.

 

Im new to road bikes and was told to use my front and rear breaks when breaking hard. I dont really find this true now. I now use the front heavier with no rear. I dont even cover it. If it gets messy there is an instinct to break (stamp) and lock it up which will turn a bad situation worse. The front brake on modern sports bikes (I.e most radial mounts) seem to have enough power to endo you at very high speeds, even with "good sports tyres"

 

Its more so that its one extra thing to worry about or perfect, and truth be told a lot of people can improve on the front brake (including me). I choose to perfect this first, then intergrate light rear brakes as that is what I feel is best for my speed and experience level.

 

At the moment, im feeding in so much front brake that by the time I start to apply the rear break its nearly time to turn in. At this point, I will cover my rear brake or even hold it on if I need to wash off a bit (!) of speed or to tighten my line.

 

In an emergency stop (straight line) I dont mind jumping on the rear, if it locks no big deal but I like to put as much front in as possible

 

Other then that, im only using my rear brake for slow speed stuff

[Cobie Fair]

In an emergency stop (straight line) I dont mind jumping on the rear, if it locks no big deal but I like to put as much front in as possible

 

Other then that, im only using my rear brake for slow speed stuff

 

Here is what we found testing a while back: when riders (of all skill levels) were using both brakes, and they locked the rear (easy to do for sure if using the front effectively), they would let go of the front. But that's the one doing the work...

 

There are a few parts to this, but to have one braking mode for regular and one braking mode for panic stopping...more complicated than I like to make riding. With the modern day bikes and tires, have to pay some attention to keeping the rear wheel on the ground under hard braking.

 

Some things to consder.

 

CF