Are drums as bad as everyone makes them out to be? A discussion.

[JDMcb7]

So it occured to me recently, are drums really as bad as people think? Everyone is all into the rear discs conversions which are really cool, but does it provide substantially more braking power versus a drum? Obviously the bling factor is an issue, that being said, we will just look at the preformance of the two.

Discs: Discs obviously have advantages in several areas. The first being under heavy braking conditions they cool faster. They also resist brake fade subsantially over drums. Discs also "self clean" themselves, in that as the rotor turns near the pad any foreign material will be scrapped off by the pad.

Drums: Drums excel in several areas and are not the primative forms of enginering many of us percieve them to be. First and formost the parking brake is substantially stronger with a drum system. Drum brakes also benefit from a something called "self energization" which actually pulls the shoe against the drum during braking, effectively doing less work.

With those points in mind does it make sense that a rear disk brake setup is going to be more effective during daily driving? The primary braking is done through the front brakes anyways, so exactly how effective are the rear brakes going to be anyways during daily driving?

I know there are exceptions, like anything, so I understand that rear disks would be better suited for those participating in things such as Auto-X because of the resistance to fade, but to me it dosen't make sense to do a rear disk swap if you are just going to drive around town because you aren't really getting any better braking. I personally will be rocking drums in the rear until I have an application where rear disks are going to be necessary. I'd love to hear more opinions on the subject.

[clarksterdotcom]

bump it up..

for myself i wanted to go rear disc because at the same time i could easily convert to ROH. and then be in the proper setup to go 5 lug down the road. i dont drive nearly fast enough daily to require the disc setup realisticaly..

but this is just my story, not an actual discussion of performence. talk more please!!!

[AccordWarrior]

I've heard that the Discs are also less affected by the weather...but then again I heard that from my driving instructor in high school who prefered Lincolns with white walls and Landau roofs.

[owequitit]

Drums are generally harder to maintain as well. They need service less frequently, but disks are SOOOO EASY!

They actually aren't necessarily worse at cooling either. It is all about surface area.

They are lighter, they are more protected against debris and F.O.D. They seem to be less likely to squeak.

Believe it or not, Ferrari was a holdout on 4 wheel drum brakes, because the were proven, reliable and light. They finally switched because of market pressures.

[accordaffair]

I much prefer discs, they have better braking power, and drums require pressure to increase stopping power, ie the harder you press the pedal the harder they stop. This is ok for a budding young guy like myself but some old people might not have the leg strength for that. Drums are ok when you're dealing with a light weight vehicle. For example on my old 125cc Honda bike, rear drums are acceptable (to a point ) and on my dad's tiny suzuki swift (think geo metro hatchback) rear drums are good enough. But when dealing with a fairly heavy four door sedan drums can only "do it" to a point. That's why Honda started putting rear discs on our cars. That wasn't some random "why not" moment, it was done for a reason. The difference between rear drums and rear discs is like night and day for stopping power.

Now I think the rear drum setup on my 90 cb7 is pretty good. It's stopping power is certainly acceptable in my opinion. But it would be better to have discs.

Of course discs tend to be a little TOO strong, in that pushing too much on the pedal can cause them too stop too much and they will lock up. Versus drums are more difficult to lock up because they don't stop as hard. You can't really 'stomp' the brakes with all around discs, where with drums you almost had to to get max braking power. On a bike locking up the front disc can mean you're going over the handlebars (hint=not good) That's why when you're learning to ride a bike, they teach you to stop with only the rear brake for safety. Later you use 80% rear, until you learn how much to balance them.

In a car with ABS theres no longer a worry about locking up the discs, and it's safe to put discs on all four wheels.

[HukedUp91Accord]

Then how come tractor trailers use drum brakes and not disc breaks if they are better for light weight vehicles.

[Turbo Dave]

so basically your saying its kind of pointless to do rear discs on a non abs car because youll probly be ending up locking up your tires when you actually are stopping hard enough to need more than drums in the back.

[azian21485]

So it occured to me recently, are drums really as bad as people think? Everyone is all into the rear discs conversions which are really cool, but does it provide substantially more braking power versus a drum? Obviously the bling factor is an issue, that being said, we will just look at the preformance of the two.

Discs: Discs obviously have advantages in several areas. The first being under heavy braking conditions they cool faster. They also resist brake fade subsantially over drums. Discs also "self clean" themselves, in that as the rotor turns near the pad any foreign material will be scrapped off by the pad.

Drums: Drums excel in several areas and are not the primative forms of enginering many of us percieve them to be. First and formost the parking brake is substantially stronger with a drum system. Drum brakes also benefit from a something called "self energization" which actually pulls the shoe against the drum during braking, effectively doing less work.

With those points in mind does it make sense that a rear disk brake setup is going to be more effective during daily driving? The primary braking is done through the front brakes anyways, so exactly how effective are the rear brakes going to be anyways during daily driving?

I know there are exceptions, like anything, so I understand that rear disks would be better suited for those participating in things such as Auto-X because of the resistance to fade, but to me it dosen't make sense to do a rear disk swap if you are just going to drive around town because you aren't really getting any better braking. I personally will be rocking drums in the rear until I have an application where rear disks are going to be necessary. I'd love to hear more opinions on the subject.

in everyday driving, you won't notice a difference - however, in light of this, everyone still upgrades big brake kits and calipers and other stuff on their street car...but i won't get into that

however, for autocrossing a fwd car, switching to discs isn't necessarily a smart move:

drums are lighter

true, drums can't provide as much clamping power, however, definately more than enough clamping power to lock up the rear tires

braking is done with a high percentage by your front brakes (i'd say around 80% depending on suspension setup)...rear brakes do nearly nothing...rear tires do nothing either so why add extra weight?

you won't stop any faster with rear discs. period.

however, with road racing, discs in the rear will help withstand brake fade, give better brake modulation, and basically evens out your braking for more stability

as a side note: some fwd speed touring cars use 0% of their rear brakes when diving deep into a corner after a high speed straight..one of the drivers for the mazda 6 said the rear tires would lift off the ground for a couple seconds...neat stuff

[aero]

Its about time someone agreed with me. Disc brake conversion is purely cosmetic. 80% of braking is done in the front, leaving 20% to the rear...obviously. Even if there is a SMALL difference, you will notice nothing.

If you felt a difference when swapped, your drums could have been bad, the new proportioning valve feels different or its all in your head.

And I am talking to 95% of the people... on the track, its possible to notice a small difference, but you have to be a good driver to take advantage of that difference. And obviously there arent many that actually track the cb7.

[JDMcb7]

I agree completely that doing the drum to disk conversion won't help you stop any faster, that is why I wonder why so many actually do this. I know it looks cool and I give props to anyone who puts in the wrench time to do it, but it's not really necessary. Obviously the lack of brake fade is the big advantage, but how many of us REALLY worry about brake fade on a day to day basis?

Also, in regards to Accordaffair, honda does indeed put drums on many of the new accords today. Look at the LX and value package models, all are sporting drums still. I think the push to 4 wheel disks accross the industry was just to provide a selling point to higher models. I still believe that drums do offer more stopping power because the do self energize, so they actually require less work to stop compared to disks.

I think this is quite a productive discussion and I hope it clears up some of the mysteries between the two braking systems, up for more discussion.

[shawn.hayden]

my .02, I agree that rear disc's are MAINLY swapped for cosmetic purposes. Simply because thats the main reason I want to do the swap...

[ACC0RD22]

Then how come tractor trailers use drum brakes and not disc breaks if they are better for light weight vehicles.

do you even understand how heavy a disc for a tractor would be? rotational mass pwns you

[thatsitbelowradarSTL]

like someone said the front braking does 80% of the stopping power (i heard it was 70%, but you get the point) and i view the rear disc conv. as worthless and a waste of time (along with the 5 lug conv.).....but for those who want it for cosmetic reasons then thats cool...but as accordaffair said..as i understood it, it was bad if you dont have abs. i would do the rear disc conv. for cosmetic reasons if i had a lot of extra money but my car is not abs so then i guess it would cause problems

overall...i think its a waste and like jdmcb7, was wondering why people were doing it, but since hayden was doing it for cosmetic reasons i see where your coming from

[micksf22accord]

i love my disc

[accordaffair]

Look at the LX and value package models, all are sporting drums still.

My moms LX came with 4 wheel discs standard.