fishtailing under rear braking

[nuttycyclist]

...

... You don't have to use the rear brake at all in most situations on the road to brake quickly and safely.

if i hadn't have done in this situation i would have been embedded in the rear end of a renault clio. 

Actually, maximum braking loads the front tyre completely and the back wheel does nothing.  Its just that most people don't use the front brake hard enough in an emergency.

I've never recovered from a front-wheel skid.  Bam! Sack of potatoes, every time.  I *usually* recover from back-wheel skids.

I have.
It's extremely rare for me to get a front wheel skid. It wasn't servere and I was going in a straight line  (until I started to skid) and hit a wet drain cover. I've had others I've recovered from too. but I don't really know what I did. I just sort of went with it. Probably a lot of luck involved too.

I have too, several times including on the motorbike.

Luck is usually the main key.

The only time it wasn't (but was) was when I was on a wet grassy field and saw a friend.  I shot up to him, jammed on the rear brake for a sideways slide round him, then for some reason jammed on the front to really get the bike going.  It was a great spin around him whilst completely sideways on both wheels, but please don't ask me to repeat it.

[LEE]

Braking on a bike is like braking on a motorbike, the same rules apply (except you tend to have less rubber on the road).

1) Back brakes DO slow you down, they are not useless.  Note, they will slow you down but will take ages to stop you.

2) The harder you brake the more weight goes to the front wheel. The front brake becomes, potentially, more and more effective and the rear less so (ever increasing potential for lock-up).

3) The most effective braking involves front and rear braking and a degree of 'feel' to continually balance it out.

In a straight line, if you get yourself low and to the back of the bike, you can put tremendous braking force to the front wheel without going over the bars.  The rear wheel under such forces will be somewhere between 100% in contact with the road and 0% in contact with the road.  There's no simple answer for the question "how hard can I use my rear brake" becasue of this variable.

All you can do is practice is a safe environment to get a feel of the force required to balance front and rear.

In general though it's an 80/20 rule for stopping quickly.  For simply scrubbing a bit of speed off or keeping your speed in check down a hill then it doesn't really matter.

Put simply, if your rear wheel is locking up and fish-tailing then you are pulling the rear's lever too hard and not using the front brake hard enough.

[Greenbank]

One huge variable is the road conditions.

On a wet road and skinny 23mm road tyres you'll lose traction from the front wheel long before the rear wheel is unweighted. In that scenario the back brake can add to the braking.

As far as the original point is concerned, I'd consider how aggressively you want to ride.

I can go a whole week of commuting (in London) without applying my brakes at more than 30% of full (i.e. wheel locking) power. Part of it is anticipation and a lot of it is just easing off slightly and not trying to get a PB on each and every commute.

Approach it too aggressively and I'm grabbing handfuls of brake all the time.

My average speed seems to be no different (and that's with an auto start/stop cycle-computer) but should I fit a sphygmomanometer I'd certainly notice the difference in my systolic over diastolic.