Heavy braking: locked rear tire

[dextasy]

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When you are braking heavily – especially on a sport(ier) bike the mass is transferred to the front wheel. During threshold “maximum” braking over 90% of the braking is done by the front wheel. You are much more likely to lock up/skid the rear wheel as there is very little downward force creating traction between it and the road.

Most pro riders do not touch the rear brake while braking heavily for this reason. Very little braking force is actually being generated. Locking the rear wheel and having it fishtail all over the place is going to lead to more issues.

If you aren’t already spend some time in an empty parking lot practicing hard braking. Let the front tire do the stopping and let the rear tire keep the bike tracked in a straight line. You should also be downshifting at the same time which will add some braking force to the rear tire. Lots of YouTube videos on how to practice your braking – don’t wait until a car is in front of you to figure it out. Especially on a non-ABS you really can only use a touch of rear brake.

what's your source for pro riders not using the rear brake?

 

[Baggsy]

I saw a guy lock up both brakes a couple of weeks ago - Oh he's down.
He releases the front as he's supposed to - He saved it!
He releases the back as he's not supposed to - Oof, free flying lesson!
Fortunately, he was going less than 30 at the time.

 

[ReSTored]

I think the counsel to keep the brakes on with a partially locked or fully locked rear wheel and to ride out the skid is, overall, poor advice. This is like telling people to never touch the brakes in a turn because it might cause a low side or stand the bike up and cause you to run wide. If the rear wheel skids out 6" then probably not a big deal and you could ride it out, if it continues to slide out and you resemble a flat tracker then you're probably going to be in big trouble.

While you are in a parking lot at slow speeds you can practice threshold braking front and rear in general and locking up the rear wheel in particular. If the bike begins to skid and the rear wheel begins to slide out then gently release pressure on the pedal to straighten the bike out. Start this at a slow speed, say 40 - 50 kph, and increase speed as you build your confidence and skill level.

Obviously you don't have the rear brake on 100%, the rear end sliding out 30 degrees and then fully release the brake....... as this is a recipe for a high side.

 

[PrivatePilot]

Just remember if you do lock up the rear just continue braking and ride it out, If you are fishtailing a bit and you suddenly let go of the rear brake your back tire will hook up and straighten and could cause you to have a nasty high side.

This is what they teach in motorcycle school, and there's plusses and negatives to it.

For a new rider who may not recognize a skid until the bike is already going sideways, it has merit. Let off the rear brake at that point and you'll likely highside as the bike snaps back to it's desired direction, and the driver continues in their initially desired direction, which would be two different trajectories at that point.

However, hold that skid long enough without countersteering (something most newbies don't have the skill to do) , and you're going to lowside in short order once the bike gets past 45+ degrees.

Both result in a crash unless you're going slow enough (or have the skill and road to countersteer through it) that you can safely ride it out and come to a stop.

For an experienced rider who feels/hears the skid right away, immediately letting go of the rear brake is perfectly fine - the bike is NOT already sideways therefore there's going to be little or no inertial forces to worry about so far as causing any loss of control.

Skill plays a big part. I've had my rear brake lockup before on particularly slick roads right after a rain starts and I instinctively let it go and then reapply the brake once traction is regained - instinct learned in my old dirt days when I was a kid.

 

[HarleyHare]

The ABS on my bike is easily worth 25% of the cost, but it wasn't that much. Emergency braking is so rare for me, that when it does happen I don't apply enough front brake (ABS not activated/not kicking back), but way too much rear (ABS activated/kicking back). I put that down to my leg muscles being stronger than my arm. If I were braking hard all the time like a racer, I would have weaned myself off too much rear brake, but because the frequency of emergency braking is so rare for me, I don't have the brain muscle to do precision balanced braking.

ABS is here to stay and only slightly less effective at preventing an accident, than totally giving up riding.

 

[J_F]

The first thing you could have done better was to avoid the necessity for heavy braking. Something catch you by surprise?

this, all of this

if you have to panic stop
forget about the rear - this will be argued

as mentioned you were lucky not to high side when the rear regained traction
trail braking the rear is useful on the road - whole other topic
and if you get off pavement it's good to know how the rear brake works

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