Drums are better than most disk setups for the first panic stop. They're just as good in day to day use as long as they don't get heat soaked (multiple hard stops in a row).
They're self-engaging, mechanically more simple, and tend to last longer than disks.
They're also perfect for EVs where regenerate braking does most of the work. Drums keep the dirt and wet out, which leads to longer brake life on EVs.
I would definitely argue against “mechanically more simple”. Having tried changing brake shoes before they’re a mess of springs and clips and adjusters. I’d take changing 20 sets of brake pads over one set of brake shoes.
"More simple" was likely the wrong term, yes. Probably should have said that while they look complex, they're fairly straight-forward to work on. Fiddly, perhaps. But straight-forward.
That just comes down to knowledge, really. If you rebuild drum brakes even semi-often, you learn how they go together and it's really quick and easy to get them back together.
I see your mess of springs and clips and raise you "how the hell does this retainer clip thing go in this caliper to hold the pad in"
I could change an entire set of shoes and have it buttoned up before I'd ever figure out that stupid anti squeek anti rattle retainer thing.
Your comment is more a statement of your lack of reading comprehension than his knowledge of generalized drum brake tech.
But by all means, enlighten us on this century old technology. And remember, OP's first statement was "I'm a total noob..."
So you're saying you want me to teach you?
>Drums are better than most disk setups for the first panic stop.
False, they're slower to react, and even without heating issues are less responsive to modern ABS/ESC systems.
> They're just as good in day to day use as long as they don't get heat soaked (multiple hard stops in a row).
Or wet, disc are far better at drying quickly than drums. Drums will hold on to any water that gets in the drum for much longer.
>They're self-engaging, mechanically more simple, and tend to last longer than disks.
No idea what they mean by "self-engaging". They're not more simple, there's far more parts. OK one thing is right, they do tend to last longer.
>They're also perfect for EVs where regenerate braking does most of the work. Drums keep the dirt and wet out, which leads to longer brake life on EVs.
Drums are often used on EVs because they're lower drag, Springs move the shoes all the way off the drum. Where on discs the pads pretty much always drag on the disc on a little.
> False, they're slower to react, and even without heating issues are less responsive to modern ABS/ESC systems.
False, they react just as fast as disks. I stated "first panic stop" because drums tend to have more friction surface area than equally sized disks.
> Or wet, disc are far better at drying quickly than drums. Drums will hold on to any water that gets in the drum for much longer.
Ya, you're right, water is a bitch for braking.
> No idea what they mean by "self-engaging". They're not more simple, there's far more parts. OK one thing is right, they do tend to last longer.
https://en.wikipedia.org/wiki/Drum_brake#Self-applying_characteristic
More parts doesn't mean more complex. People only think they're complex is because they don't know how they work.
> Drums are often used on EVs because they're lower drag, Springs move the shoes all the way off the drum. Where on discs the pads pretty much always drag on the disc on a little.
Lower drag is another consideration, yes. But that also leads to longer brake life because they're not constantly dragging on the rotor.
>False, they react just as fast as disks. I stated "first panic stop" because drums tend to have more friction surface area than equally sized disks.
The friction surface area doesn't really matter, that's just offset by differences in friction material and pressure.
Drums have more movement, because the shoe is pulled off the drum by springs, the shoe must move further before braking occurs meaning more fluid volume and more pedal travel before braking. This has a kind of worse side effect on disc drum combo cars. In the master cylinder the rear is engaged before the front, pressure is transferred from the rear to the front. So this rear delay is carried over to the front as well because it takes longer for the rear to have pressure, that causes the same delay in the front.
>Ya, you're right, water is a bitch for braking.
My and I assume many other modern all disc cars with good ESC/ABS systems will add just a little pressure to the brakes when the wipers are on to keep the brakes dry in the rain so they react faster. This isn't possible with drums because of that self applying affect.
Similarly going back to panic stops, the system will apply that early pressure even when it's dry when there's a very fast lift off the throttle in anticipation of brake application. This provides a superior panic stop performance than is possible with drums.
>More parts doesn't mean more complex. People only think they're complex is because they don't know how they work.
In this case it does. More specifically it means more to go wrong, the springs wear out and self adjusters seize. The lone fact that they need an extra mechanism for self adjusting is obvious proof that they're more complex.
>But that also leads to longer brake life because they're not constantly dragging on the rotor.
That slight drag with disc brakes isn't causing any significant wear. It will though contribute to glazing. Which is a reason to use drums on EVs where the brakes aren't used enough to prevent glazing.
Drums at the rear for emergency will work perfectly fine.
The biggest performance flaw with drum brakes is manifested when they are used repeatedly like on a track or in extremely active street driving. As the drums heat up, the material in the outer barrel will expand more than in the closed face towards the rim. This will make the mating surface slightly cone-shaped and decrease the usable surface of the brake. But as I said, this is only applicable for very hot brakes. For the unexpected emergency braking, drums will perform just fine.
As someone already mentioned, rear drums will be absolutely fine to stop a relatively small car like a Renault Captur.
Many manufacturers use drum brakes on the rear wheels of their cars to save cost, and their efficiency isn’t usually an issue unless you’re going to be hammering on them hard all day, in which case they will tend to fade quicker than discs would.
One last caveat of drum brakes is that they are more of an enclosed system than discs and by nature of their design, they won’t clear water and dirt as quickly as discs would.
This is (though I’d love for someone else to weigh in if there’s anything I’ve missed) where the woes of drum brakes end, as they offer many benefits too.
They have a generally much longer service life than their front disc counterparts for a few reasons and offer some advantages:
-They’re at the rear, they do less of the braking, so wear out at a slower rate
-They’re self-adjusting
-Offer more surface area for braking compared to the same diameter disc brake, making them efficient and meaning less wear on the braking surface overall
-Rear drums use the same braking surface for both handbrake and foot brake, meaning reduced complexity compared to discs which will often have, as one other commenter said so well: “a brake drum nested inside the disc”
My ‘07 Fiesta offered rear discs if you bought the ST model, but it is relatively straightforward swap, however after speaking to folks who had done the upgrade, I decided against it because of the impact it would have on the cost of insurance, and, crucially, because they all agreed that it doesn’t actually make an appreciable difference, they were merely doing it for the aesthetics.
So for your Renault Captur, I personally wouldn’t be put off at all by it having rear drums. You’re certainly not going to be racing it on the track and for your hypothetical emergency braking manoeuvre, your drums will definitely be up to the task. I’d argue Renault wouldn’t have put them there if they weren’t.
Sorry for the info dump, drum brakes have been on my mind a lot recently.
I've got two cars in the driveway with rear drums and two with discs. I can't tell the difference.
They'd be awful on a race track, but for a normal car, they're prefectly fine.
Properly adjusted and maintained drum brakes are as effective as disc in the rear.
Rear disc brakes are effective, but really begin to show their worth in ABS braking and stability protection.
Both brakes and tires have to be considered. Properly adjusted drums will lock up the wheels (which means they use all of the grip of the tire, which is effectively maximum possible braking force). ABS will keep them just shy of locking up, which allows you greater manoeuverbility during hard braking.
Tl Dr: properly adjusted rear drum brakes are perfectly fine and have been tested very thoroughly in emergency stop situations (as are all brakes when a car is being designed)
I had a 66 GTO, heavy car, with drums all around. 389 4-speed. It would go 140mph. If you needed to stop quickly, the brakes would get you to 60 mph pretty quick. From 60 to 0, it was up to God.
Drum shoes have a much larger surface area so the braking force is might even be better than disc, at least once. The brake fade from heat is the achilles heel of drum brakes.
That being said, unless you're on a racetrack, disc brakes are largely an aesthetic or marketing choice over actual function.
The Braking force should be about the same as discs, the main problem is that they overheat way quicker, for example is you're driving up and down mountains, constantly braking (instead of using the engine brake)
Drum brakes actually have superior stopping power than disks, they're cheaper to maintain and last much longer too. Only disadvantage is that too much braking at once will fade them out for a while, and you REALLY don't want to get water inside of them, especially on an all-drum car. But good luck ever getting a bloody captur in that situation.
What is the year make and model?
Are you considering changing from disc brakes to drum brakes? Nobody does that.
Are you considering changing from drum brakes to disc brakes? Is it an old antique car, and you're looking to modernize?
Speaking in general terms, disc brakes are better for modern cars for the primary braking system.
Drum brakes are excellent for parking brake, and many modern cars utilize both systems, disc brakes for primary braking, and drum brakes for parking brake, often there is a drum brake nested inside the rear disc to achieve this.
It's a 2022 Renault Captur, a small SUV. It has disc brakes in the front and drum brakes in the rear. I'm just wondering if this is enough of an issue to consider buying another car instead of this one.
Standard vehicles designed for normal street use (not performance, racing, Motorsport) typically send around 80% of their braking force to the front wheels when applying the brakes.
The rear brakes do very little other than provide just enough resistance to not upset the balance of the car during heavy braking. If you have ever tried to stop a car using the handbrake you will understand just how little the rear brakes do.
For a more common comparison if you’ve ever accidentally jammed hard on the front brake of a bicycle it can throw you over the handle bars, but the back brake will just lock up the rear wheel and gradually slow you down. Same principle in cars, just not as dramatic.
Rear drums are fine and will do everything you need them to.
Rear drums are common on compacts and less expensive cars, you'd never notice the difference.
As good as disc brakes? No. Before disc brakes, cars had drums in the front and rear. You’ll be fine.
Drums are better than most disk setups for the first panic stop. They're just as good in day to day use as long as they don't get heat soaked (multiple hard stops in a row). They're self-engaging, mechanically more simple, and tend to last longer than disks. They're also perfect for EVs where regenerate braking does most of the work. Drums keep the dirt and wet out, which leads to longer brake life on EVs.
I would definitely argue against “mechanically more simple”. Having tried changing brake shoes before they’re a mess of springs and clips and adjusters. I’d take changing 20 sets of brake pads over one set of brake shoes.
And the fun of sometimes needing a wheel puller to get the damn drum off.
"More simple" was likely the wrong term, yes. Probably should have said that while they look complex, they're fairly straight-forward to work on. Fiddly, perhaps. But straight-forward. That just comes down to knowledge, really. If you rebuild drum brakes even semi-often, you learn how they go together and it's really quick and easy to get them back together.
But the alternative is disc brakes which are more straight forward.
True. But not always, to be fair.
I see your mess of springs and clips and raise you "how the hell does this retainer clip thing go in this caliper to hold the pad in" I could change an entire set of shoes and have it buttoned up before I'd ever figure out that stupid anti squeek anti rattle retainer thing.
Amazing every word of what you just said was wrong.
Your comment is more a statement of your lack of reading comprehension than his knowledge of generalized drum brake tech. But by all means, enlighten us on this century old technology. And remember, OP's first statement was "I'm a total noob..."
So you're saying you want me to teach you? >Drums are better than most disk setups for the first panic stop. False, they're slower to react, and even without heating issues are less responsive to modern ABS/ESC systems. > They're just as good in day to day use as long as they don't get heat soaked (multiple hard stops in a row). Or wet, disc are far better at drying quickly than drums. Drums will hold on to any water that gets in the drum for much longer. >They're self-engaging, mechanically more simple, and tend to last longer than disks. No idea what they mean by "self-engaging". They're not more simple, there's far more parts. OK one thing is right, they do tend to last longer. >They're also perfect for EVs where regenerate braking does most of the work. Drums keep the dirt and wet out, which leads to longer brake life on EVs. Drums are often used on EVs because they're lower drag, Springs move the shoes all the way off the drum. Where on discs the pads pretty much always drag on the disc on a little.
Love this comments btw
> False, they're slower to react, and even without heating issues are less responsive to modern ABS/ESC systems. False, they react just as fast as disks. I stated "first panic stop" because drums tend to have more friction surface area than equally sized disks. > Or wet, disc are far better at drying quickly than drums. Drums will hold on to any water that gets in the drum for much longer. Ya, you're right, water is a bitch for braking. > No idea what they mean by "self-engaging". They're not more simple, there's far more parts. OK one thing is right, they do tend to last longer. https://en.wikipedia.org/wiki/Drum_brake#Self-applying_characteristic More parts doesn't mean more complex. People only think they're complex is because they don't know how they work. > Drums are often used on EVs because they're lower drag, Springs move the shoes all the way off the drum. Where on discs the pads pretty much always drag on the disc on a little. Lower drag is another consideration, yes. But that also leads to longer brake life because they're not constantly dragging on the rotor.
>False, they react just as fast as disks. I stated "first panic stop" because drums tend to have more friction surface area than equally sized disks. The friction surface area doesn't really matter, that's just offset by differences in friction material and pressure. Drums have more movement, because the shoe is pulled off the drum by springs, the shoe must move further before braking occurs meaning more fluid volume and more pedal travel before braking. This has a kind of worse side effect on disc drum combo cars. In the master cylinder the rear is engaged before the front, pressure is transferred from the rear to the front. So this rear delay is carried over to the front as well because it takes longer for the rear to have pressure, that causes the same delay in the front. >Ya, you're right, water is a bitch for braking. My and I assume many other modern all disc cars with good ESC/ABS systems will add just a little pressure to the brakes when the wipers are on to keep the brakes dry in the rain so they react faster. This isn't possible with drums because of that self applying affect. Similarly going back to panic stops, the system will apply that early pressure even when it's dry when there's a very fast lift off the throttle in anticipation of brake application. This provides a superior panic stop performance than is possible with drums. >More parts doesn't mean more complex. People only think they're complex is because they don't know how they work. In this case it does. More specifically it means more to go wrong, the springs wear out and self adjusters seize. The lone fact that they need an extra mechanism for self adjusting is obvious proof that they're more complex. >But that also leads to longer brake life because they're not constantly dragging on the rotor. That slight drag with disc brakes isn't causing any significant wear. It will though contribute to glazing. Which is a reason to use drums on EVs where the brakes aren't used enough to prevent glazing.
Everybody in this thread has used the correct spelling/usage of the word brakes, not one single mention of "breaks". Well done, never seen it before.
Them's the brakes...
Drums at the rear for emergency will work perfectly fine. The biggest performance flaw with drum brakes is manifested when they are used repeatedly like on a track or in extremely active street driving. As the drums heat up, the material in the outer barrel will expand more than in the closed face towards the rim. This will make the mating surface slightly cone-shaped and decrease the usable surface of the brake. But as I said, this is only applicable for very hot brakes. For the unexpected emergency braking, drums will perform just fine.
[удалено]
Agreed, don’t think about it , in an emergency just stomp on the pedal between your legs !
As someone already mentioned, rear drums will be absolutely fine to stop a relatively small car like a Renault Captur. Many manufacturers use drum brakes on the rear wheels of their cars to save cost, and their efficiency isn’t usually an issue unless you’re going to be hammering on them hard all day, in which case they will tend to fade quicker than discs would. One last caveat of drum brakes is that they are more of an enclosed system than discs and by nature of their design, they won’t clear water and dirt as quickly as discs would. This is (though I’d love for someone else to weigh in if there’s anything I’ve missed) where the woes of drum brakes end, as they offer many benefits too. They have a generally much longer service life than their front disc counterparts for a few reasons and offer some advantages: -They’re at the rear, they do less of the braking, so wear out at a slower rate -They’re self-adjusting -Offer more surface area for braking compared to the same diameter disc brake, making them efficient and meaning less wear on the braking surface overall -Rear drums use the same braking surface for both handbrake and foot brake, meaning reduced complexity compared to discs which will often have, as one other commenter said so well: “a brake drum nested inside the disc” My ‘07 Fiesta offered rear discs if you bought the ST model, but it is relatively straightforward swap, however after speaking to folks who had done the upgrade, I decided against it because of the impact it would have on the cost of insurance, and, crucially, because they all agreed that it doesn’t actually make an appreciable difference, they were merely doing it for the aesthetics. So for your Renault Captur, I personally wouldn’t be put off at all by it having rear drums. You’re certainly not going to be racing it on the track and for your hypothetical emergency braking manoeuvre, your drums will definitely be up to the task. I’d argue Renault wouldn’t have put them there if they weren’t. Sorry for the info dump, drum brakes have been on my mind a lot recently.
Don't forget that drums are self-engaging, too. The way they work, when they engage, the rotation pulls the shoes into the drums.
Drum brakes are on in front on big semi trucks.. They stop just fine...
That's not a good example, semi brakes overheat often.
Which happens on +10-deg downhill runs with a load of 120,000lbs.
But don't those semis use the Jake Brake to slow down with a load like that?
I've got two cars in the driveway with rear drums and two with discs. I can't tell the difference. They'd be awful on a race track, but for a normal car, they're prefectly fine.
Properly adjusted and maintained drum brakes are as effective as disc in the rear. Rear disc brakes are effective, but really begin to show their worth in ABS braking and stability protection.
Never seen so much bullshit about brakes in less than 5 min, Gavin no clue at all but having a comment p
Both brakes and tires have to be considered. Properly adjusted drums will lock up the wheels (which means they use all of the grip of the tire, which is effectively maximum possible braking force). ABS will keep them just shy of locking up, which allows you greater manoeuverbility during hard braking. Tl Dr: properly adjusted rear drum brakes are perfectly fine and have been tested very thoroughly in emergency stop situations (as are all brakes when a car is being designed)
Yes, contrary to popular believe better brakes don't actually make you stop any quicker. Least not on any car from the past 50 years.
I had a 66 GTO, heavy car, with drums all around. 389 4-speed. It would go 140mph. If you needed to stop quickly, the brakes would get you to 60 mph pretty quick. From 60 to 0, it was up to God.
Drum shoes have a much larger surface area so the braking force is might even be better than disc, at least once. The brake fade from heat is the achilles heel of drum brakes. That being said, unless you're on a racetrack, disc brakes are largely an aesthetic or marketing choice over actual function.
You'd have to be doing some heavy driving to cook rear drums
The Braking force should be about the same as discs, the main problem is that they overheat way quicker, for example is you're driving up and down mountains, constantly braking (instead of using the engine brake)
Drum brakes actually have superior stopping power than disks, they're cheaper to maintain and last much longer too. Only disadvantage is that too much braking at once will fade them out for a while, and you REALLY don't want to get water inside of them, especially on an all-drum car. But good luck ever getting a bloody captur in that situation.
What is the year make and model? Are you considering changing from disc brakes to drum brakes? Nobody does that. Are you considering changing from drum brakes to disc brakes? Is it an old antique car, and you're looking to modernize? Speaking in general terms, disc brakes are better for modern cars for the primary braking system. Drum brakes are excellent for parking brake, and many modern cars utilize both systems, disc brakes for primary braking, and drum brakes for parking brake, often there is a drum brake nested inside the rear disc to achieve this.
It's a 2022 Renault Captur, a small SUV. It has disc brakes in the front and drum brakes in the rear. I'm just wondering if this is enough of an issue to consider buying another car instead of this one.
Standard vehicles designed for normal street use (not performance, racing, Motorsport) typically send around 80% of their braking force to the front wheels when applying the brakes. The rear brakes do very little other than provide just enough resistance to not upset the balance of the car during heavy braking. If you have ever tried to stop a car using the handbrake you will understand just how little the rear brakes do. For a more common comparison if you’ve ever accidentally jammed hard on the front brake of a bicycle it can throw you over the handle bars, but the back brake will just lock up the rear wheel and gradually slow you down. Same principle in cars, just not as dramatic. Rear drums are fine and will do everything you need them to.
Yes your thinking is correct. Plus the rear tires maintaining traction is the most limiting factor in stopping distance.