My experience with black ice and bikes, is to unexpectedly fall flat on my face because the front wheel loses all grip. Without even getting to the point of trying to brake..
My experience with black ice and bikes, is to unexpectedly fall flat on my face because the front wheel loses all grip. Without even getting to the point of trying to brake..
Locking and then suddenly reacquiring grip on the rear wheel causes highsides on motorbikes, it's when you fly out of the seat and into the oncoming 18-wheeler. But it's quite hard to do on bicycles.
Fronts are useful when you have to decelerate rapidly while travelling in straight line, but in turns you just don't touch them ever.
edit: and on a decent motorbike/scooter you learn to not use brakes except in emergency, 95% of all deceleration is handled by just dropping the throttle.
Sheldon Brown talked about this [0]:
> Skilled cyclists use the front brake alone probably 95% of the time, but there are instances when the rear brake is preferred: slippery surfaces, bumpy surfaces, front flat, broken [front brake]
> When leaning in a turn, traction is shared between braking and turning. Using both brakes together reduces the likelihood that one wheel or the other will skid and dump you. The steeper you lean, the less you can brake, so moderate your speed before a curve. When you are leaning deeply, you need to release the brakes entirely.
> Using both brakes together can cause "fishtailing." If the rear wheel skids while braking force is also being applied to the front, the rear of the bike will tend to swing past the front, since the front is applying a greater decelerating force than the rear. Once the rear tire starts to skid, it can move sideways as easily as forward.
I broke some ribs a couple of years ago on a downhill trail due to fishtailing. I should have dismounted, but I had not realized that the surface had turned from gritty to muddy.
In a turn you either apply energy if that is at all possible (usually), or just steer. It is recommended to accelerate inside a turn, because that way you can better control grip on the rear due to not accidentally engine-braking (not applicable to bicycles), and because thrust on the rear wheel helps the bike into the turn (applicable to bicycles).
Braking in a turn is a last-effort thing, taken only if you are certain that it'll lessen damage from otherwise imminent crash.
Biking is traction/grip control at all times. Traction is always shared between steering and brake/accel. You do not want less control in a turn, and loss of traction means loss of steering.
So you do not ever brake in a turn.
You decelerate on a straight before it. If a turn goes bad for whatever reason, that means that a) you made a mistake entering it at the speed you did, and b) now you choose what to crash into, and then execute the crash while hoping that your protection holds, which might include hard front brake and a steering input so that you lowside feet (and bike) first into the obstacle. But not before.
So the first lesson of bike-riding is being aware at all times of available traction.
95% use of fronts follows: you only use them on straights, and there they are much more efficient than rears because the whole mass of you and bike enhances front wheel traction. cf. the wheelie.
As an example, pedaling while turning is often a bad idea because of the risk of pedal strikes, so acceleration inside a curve is often out of the question. And braking obviously reduces the grip available for turning, so braking while turning is only done in an emergency situation. But if you are going to brake while turning, using only the rear brake is suboptimal on a bicycle.
It doesn’t feel as good as decelerating before, and is most definitely not as safe as you clearly explained.
There are 2 benefits of actually using brakes (smartly as comments say) - leaving deceleration to the motor wears it down much faster, and repairs are more complex/expensive than changing pads/disc of brakes. Second reason is more important - folks behind you know whats happening, thats why brake lights are so strong. Don't expect 100% of the folks watching you closely 100% of the time, thats incorrect and dangerous expectation. On bike you are the most fragile participant of the traffic, its in your interest to signal your behavior to others as clearly as possible.
Not in the slightest, and I have no idea where this idea even came from. Whatever amount of stress the engine and rest of the drivetrain is under even at maximum engine braking, it experiences significantly more under any hard acceleration. Even semi truck jake brakes that actually reconfigure the engine's air flow to generate even more deceleration forces than would otherwise be possible max out at a fraction of the acceleration powers that same engine is capable of producing.
The only part of a standard automotive drivetrain that has significant directional differences in strength/wear would be the differential gears, but even that difference isn't going to matter in anything close to normal use. If you're doing clutch drops in reverse that's another matter.
The biggest risk to anything drivetrain-related from engine braking would be badly shifting a manual transmission and either damaging the transmission itself or choosing the wrong gear and over-revving the engine.
The brake light thing I fully agree with you though. I love engine braking when I'm doing performance driving as much as the next guy, but I won't do it in traffic for anything more than holding speed on a downhill for that reason. Significant deceleration in traffic should always be accompanied by brake lights.
It's motorcycling basics really.