I just noticed the fact he was on the aerobars. I replayed the video about 5 times and still laughed each time

I've just come back from a ride on a gravelly bit of downhill road with my touring bike. The rear brake works a treat on it, and for a while there, I was keeping my speed down with the rear only.

In slippery conditions, my inclination is to use the rear brake to (a) determine how slippery the surface really is should it momentarily lock up and so I can determine just how hard I can brake on the front before disaster looms and (b) to reduce the braking force required on the front wheel -- I would rather correct a rear-end lock-up than go down because grip on the front tyre has gone because I've locked up the brake.

On one of the aforementioned classes with braking practice on grassy slopes, I grabbed a whole lot more front brake than I needed, and I was dumped sideways on the ground in an instant, whereas I could hold a rear-end lock-up for 15 or 20 metres.

This is one of the few bits of Sheldon's wisdom that I wholeheartedly disagree with.

Using both brakes is best! Push yourself back in the saddle a bit for firm brake application.

Get your ass off the saddle and over the rear wheel, with the saddle's nose under your sternum for really firm applications and on especially steep declines. I don't usually have to resort to that on my road bike but I think it was Cadel I saw do it on a downhill in the TdF this year. I do it all the time on my MTB.

I like to keep my rear brakes detuned a bit so that I don't lock the rear so much.

Interesting vids on page one. At first I thought that girl had got her helmet strap caught up in her brake caliper and/or spokes, but I don't think her helmet was low enough for that. Hell of a time to take her helmet off whatever the case.

And that Fredly team time trial disaster, WOW! Definitely looks like he snapped a few spokes there. Some serious wheel overlap there but I can see why he didn't seem overly concerned about it as it seemed like the guy in black kit was gonna sit on the front dude's wheel. Then the guy in black kit decided to move to the left a couple of feet for no apparent reason.

The crasher was above his saddle but seemed to be a little forward of his saddle when he bit it. Having his weight a little more aft might have reduced the severity of his crash landing somewhat or possible averted it alltogether.

Yesterday's ride

I released both brakes and the bike straightened up. In a panic stop, by definition there's not much time or distance available, so a rear fishtail just adds to the panic. I could have just released the back, but I didn't know any better at the time.

On the wheel overlap crash video, at least the guy did a nice tuck and roll instead of sticking his arm out to stop his fall. (He didn't have time to react, so it was lucky.)

Yeah, you've got to have a bicycle really sideways at a really high rate of speed to highside from releasing the brake on a locked-up rear wheel.

Unless of course you go from being sideways and locked up on a patch of sand onto a patch of clean pavement or locked up on a wet manhole cover to a patch of damp pavement or a patch of black ice onto not so icy road ...

...well that stuff doesn't even require being locked up in the brake department either, just need your rear wheel to be sliding sideways a bit, then flip!

Yeah, you've got to have a bicycle really sideways at a really high rate of speed to highside from releasing the brake on a locked-up rear wheel.

Unless of course you go from being locked up on a patch of sand onto a patch of clean pavement or locked up on a wet manhole cover to a patch of damp pavement or ...

My single speed/track bike only has one brake and it's on the front. Easier to take it off to go fixie and track riding. If I ride it on the road it's not a problem.

Rowan makes a good point here - sometimes traction is questionable, and a rear wheel lockup is easier to control than a front one. I did the gran fondo part of a local road race that includes 18% grades on gravel, both up- and downhill. I didn't even think about touching my front brake on those downhills!

A skidding wheel has less traction than a rolling wheel, so I would say that it does not help the braking. However, if you are upright and going straight, it won't hurt all that much. It is very easy to lock up the rear wheel under maximal braking, since so much of the traction is transfered to the front wheel. I have done it just about every time I have had a true panic stop situation. I can avoid locking the rear wheel just about every time I PRACTICE maximal braking, but that is sooo different than when you are actually going to collide with something.

In the tri-bar incident vid, it appears his front skewer was opened when he rubbed wheels...which led to a loose wheel in the forks...I'm sure that was terrifying.

While both videos show someone going over the bars, neither one is just regular braking. In the first, the girl was taking her helmet off so only one hand on the bars and that hand/arm was probably not holding her weight back so when she braked all of her body's weight moved forward which then tossed her. In the second, by the time the guy goes over the bars he's lost 1/4 of his spokes (at one point in the video someone says 4 of 8 spokes on the one side of the wheel), possibly has a loosened skewer, is riding on the shoulder in a loose surface and his heart rate is probably hitting 300 knowing he just saved himself from hitting blacktop at 35mph.

Thanks to reading threads on BF (silly me) and reading some other info, I've gone to using my front brake almost exclusively on dry, smooth pavement. I've found it makes riding/stopping more stable and controllable. I generally only use the rear once I'm below 10mph and coming to a complete stop. As has been mentioned, braking in wet or loose surface conditions requires more balance between front and rear.

Only problem I have is I ride on the road 5 or 6 times a week but go mounting biking 2 or 3 times a month. Off road, using only front brake is a good way to wash out your front wheel and get into a lot of trouble (while giving your buddies a good laugh).

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I'm assuming your riding a full suspension?

I also come from mountain biking and with my hard tail, all the real braking HAS to come from the front... as you are travelling over rutted ground the rear is skipping over the bumps and simply has little/no traction, so the rear brake is simply to stabilise the situation. The front does all the work.. a large volume front tyre and suspension maintains your contact patch to the dirt and you just learn to lean on it and the back will simply follow!
I have found that my road bike is more capable coping with this than I could have imagined, and as long as you don't go silly on loose surfaces (please brake before the curves) it is often our imagination that limits all our abilities

Brakes (and braking) is not a binary proposition. You're allowed to use them in graduated amounts.

Almost all bicycle brakes can lock up either wheel quite easily, and once locked up, there is NO traction on that wheel. Not a good thing.

While the majority of braking comes from the front wheel, I aim to apply just enough pressure to maximize front and rear braking, just short of breaking loose. When you're depending on a tire-to-road interface that consists of two square inches of rubber, I say use as much brake as you have available.

That's happened to me twice in panic situations, long ago. Your heart stops for a split second, but, as long as you remember ( or have a reflex ) to let go of the rear brake, you don't go down.

I still use the rear brake when I need to stop quickly, because until you hit the point of actually lifting the back wheel, it's doing something to slow you down. But some quick stop drills helped me train myself to mostly pull with the left hand when I want to stop in a hurry.

Amazing! You've discovered a frictionless material, surely perpetual motion is to follow, since the coefficient of kinetic friction of rubber on asphalt or concrete is 0!

Or do you mean that you can't turn without a rotating wheel, and that a sliding tire has less friction?

Although traction and friction have something to do with each other, they are not the same. And of course, "no traction" was a phrase and not an exact measurement. Anyone who doesn't realize this is... well... probably an engineer

I have always been taught with bikes and cycles. Apply both brakes, front brake is doing the most stopping. If your back wheel starts to lock, slightly lighten the pull on both. The back wheel skidding is generally an indication that you are on the front brake too hard. Obviously this is a "within reason" type thing and assuming you are not on the back lever with the death grip.

Guilty as charged, although for the sake of argument: https://en.wikipedia.org/wiki/Traction_(engineering) "Traction refers to the maximum frictional force that can be produced between surfaces without slipping"

I really mostly objected to the emphasis on the word NO.

If the two surfaces are slipping, there couldn't be any traction, then, huh!

Good enough for the BF Brain Trust (© 1923, pcad the magnificent).