z415

Like I said, I'm not a car expert. Just never had an Anti-lock Braking System activate coming out of a driveway or just when I was driving on ice, only when braking.

z415

Your bike brakes don't lock either because your brakes are inherently weak, has minute or large mis-alignments, are ridden in conditions that diminish their braking power, or you are a good cyclist. ABS is a computer and sensor system. You are your bike's ABS.

flatlander_48

Use the rear brake heavier and first...

jamiewales

It might be my hydraulics bbrake system, i am use to it, i would buy this break if so

jamiewales

When i am going down the hill it does not matter!

jamiewales

It is a stoppng power?

Zan

Chuck Norris' mountain bike has ABS in his hydraulic disc brakes. He never uses brakes, though.

BarracksSi

[tangent]
Anyone who has a car with ABS needs to learn what it's like when it engages. It's an interesting sensation -- mine makes a rough-sounding "RRRRR" noise and makes the brake pedal buzz. If this were to happen on a bike, you'd probably feel the brake lever vibrate. There are motorcycles now equipped with ABS brakes, and demonstrations of them side-by-side with non-ABS motorcycles make a pretty convincing case for having them.
[/tangent]

Hmm... well, let's see...

Can you lock up the rear tire alone? Get yourself up to a decent speed and jam on the rear brake. Assuming that your hands aren't unusually weak, you should be able to make the rear tire skid pretty easily.

Can you lock the front brake completely? Try this: lift up the rear of the bike, squeeze the front brake lever, and see if you can make the front wheel roll. The wheel should NOT be able to roll at all if you're putting decent effort into the front brake lever.

IF you can't do either of these things, there's something wrong. To restate what others have said already -- your calipers could be out of adjustment, you might have air in the lines, you might have oil on the pads, etc.

Go here and get started:
https://www.parktool.com/repair/byreg...mageField2.y=9

flatlander_48

No, that wasn't quite it. Moving slowly in my driveway, slowing down under braking and on thin ice. These conditions occurred simultaneously, not exclusively...

HandsomeRyan

well stated.

jdon

Firstly, ABS requires electrical input from independent wheels speed transmisometers. Those outputs have to be run through a computer then hydraulics valves open or close to modulate wheel speed. Bikes don't have this and it would be heavy and expensive to install. Most hydraulic brakes are pretty linear in that the harder you pull, the more pressure to the pads, the more stopping force. If you are just slowing down, your brakes are not functioning properly or are not of an appropriate size for your weight. Get them checked and set up by your bike shop. It may just be contaminated pads or the lines need bleeding.

deraltekluge

That's because your brakes are screwed up, and not working correctly. They should be capable of lockup...it's your responsibility as a rider to handle the ABS equivalency by controlling the braking force to prevent lockup.

My experience with hydraulic disks on a bike is that they have great braking power, but still are easy to modulate to prevent lockup.

flatlander_48

On the order of 20 apply/release cycles per second, in case anyone thinks that they can physically do what ABS does...

jdon

Yes, I guess I have to pay attention and think while typing. I meant to say transducer. Oh well, an aging brain is a funny thing. As to your second comment, yes, you are being a picky arse, and a big one but hey, everything in TX is big. More accurately, a valve would modulate hydraulic pressure which would regulate the wheel speed. Happy?

Regardless, due to the components required, they won't be on bicycles.

BarracksSi

Engineering nerd alert!

C'mon, guys, warn us before you start geeking out...

flatlander_48

20 times / sec = .050 sec

Human finger reaction times are more like .010 to .020 sec or longer. Note I said finger. I don't think you could get your foot to do that. And, if you could, it might only be once.

flatlander_48

Yes, but given the sampling rate and that a reaction may be needed at any one of those samples, a need-no need situation can arise and go away before a human could respond.

enine

It doesn't matter how fast a human or computer can modulate, the brake fluid will dampen the pulses so at the brakes they can't tell the difference. The thing that makes humans better than ABS is we can see the road and see whats under the tires. There are situations where you want the wheels to lock up such as loose snow, gravel, dirt in order to build up some loose material in front of the tires. I've learned that some 4x4 vehicles will disable abs when in low range to prevent the vehicle from running away when on loose material, I was able to control the input to the computer by switching the low rage gear input to it off and on and test in a controlled area and can beat ABS at stopping shorter easily. I've been in situations were there was no where to steer left or right and had to stop fast and ABS released the pressure when one wheel locked and felt the vehicle take off then. Newer ABS systems that are 4 channel are no where as bad but the older stuff is downright dangerous.

enine

Yes, the compressabilility is very low but when you modulate a valve at a high frequency the amount of movement is very low and the fluid dampens it. Same with modulating the valuves in an automatic transmission to give smoother shifts, it simply causes the pressure to ramp up, it doesn't make the end actutor pulse.

cyccommute 

Rim brakes are disc brakes. They just have a much larger rotor. Current 'disc' brakes just use a different pad material that allows them to clamp harder. You could use the same material on a rim brake pad but the rim would wear down faster. Since the rim has other functions, i.e. supporting the bike and holding the tires, etc, and they cost more to replace, making them wear faster is probably a good idea.

Phantoj

I don't see how this test works. How is the front wheel being weighted, or are your brakes OK if they are strong enough to lock up an unweighted wheel...?

BarracksSi

Sorry if I wasn't clear; the front wheel remains on the ground and supports the entire weight of the bike as you stand alongside it. Hold the handlebar and front brake lever with one hand, and lift up the rear with your other hand. Hold the bike in such a way as if you were going to roll it forward on the front wheel, almost like a "stoppie", the opposite of a "wheelie".

Then, roll the bike forward on its front wheel, and apply the front brake. You should be able to completely stop the wheel with only moderate squeezing pressure on the front brake lever. Even if you give the lever quick, short jerks, it should stop instantly every time.

If that doesn't happen, go back to the link I posted and learn how to adjust it, or take it to a shop and have them help you out.

GTALuigi

my disk brakes are mechanical (i believe it's safer)

from my own personal believe, i can only think about trouble using hydraulic brakes, if anything happens to your cable, you'll lose the liquid inside the tubes, and thus lose your brakes.

mechanical brakes can be fixed or patched up, without having to bring an extra bottle of brake fluids.

Now regarding the actual topic ABS brakes for bikes.

yes there is, and it's called Regeneration brakes, but you'll only get those with Ebike systems.

The feeling of breaking with the ebike regen is amazing, it feels exactly like when you step on a car ABS brake.

you get that Brrrhhh...Brrrhhh...Brrrhhh...Brrrhhh...Brrrhhh... pumping feel, but in your hands instead of your leg, since the brake levels are controlled by hand in a bike.

the plus side to that is, on long down hills, you can really recharge a bar of battery simply superb!

BarracksSi

But do they prevent brake lockup, even when pulling hard on the lever while trying to stop on a slick/wet surface? That's what the ABS -- Anti-lock Brake System -- does, not just make a humming sensation. I wouldn't expect that regenerative brakes actually prevent lockup, but if so, then that's pretty cool.

(side/snide comment -- we've had anti-lock brakes on cars for how many years, and people still don't know what they're for or what happens when they're activated?...)

clancy98

for all intents and purposes, rim brakes are NOT disc brakes, congratulations on the technicality though!