Rear Drums vs Rear Discs

ubu

Just wondering what peoples opinions are about buying a new car with Front Discs and Rear Drums as opposed to discs all round, is there much of a difference? is stopping distance altered in any way? The mother is looking at a car in 2 different spec levels, one has discs all round and the other doesn't, even though its the higher spec one!
Anyway i told her, it wouldn't make a difference in braking for her but discs are handier for servicing and maintenance etc, anyone else got an opinions on this?

maidhc

You should get better braking from discs, but in normal cars I dont think its going to make much of a difference. Discs certainly dissapate heat faster, but again in normal cars in ordinary driving, this shouldnt be a huge issue. The front brakes do most of the braking anyhow.

I suspect the drive towards rear discs in cars over the past 5-8 years is down to the prevalence of alloy wheels (making the braking system visable), more than anything else.

bazz26

My current car has disc brakes front and back compared with my previous car (old model of the same car) which only had discs in the front.

I notice the difference alright, the brakes in my current car are better.

mike65

Drums are so mumsy! Perfect then!

Mike.

AMurphy

All else being equal, gofor disks all round. More reliable, less fade and easier to service.

JohnCleary

bazz26 wrote:

I notice the difference alright, the brakes in my current car are better.

Prob cause theyre better designed breaks as opposted to rear disks being so much better than drums :rolleyes:

Front brakes do 80% of the braking.
The advantage of disks at the rear are, as said, easier maintenance.
Also cosmetic, car looks much nicer with discs at the rear.
They do make the ever so slight difference, but tbh I doubt your mother would be doing much high speed driving needing breaking-point stopping distances..

A guy I know dropped a V6 in a 1998 Rover 200 (pushing out 300 odd BHP as opposed to 105, always on the track etc...) and still has drums on the back!

bazz26

Fair enough but I thought having discs both front and back would improve your braking system especially in conjuction with ABS via EBD (Electronic Brake Distribution) which most modern cars have?

ubu

Mike, its not that mumsy a car she's getting one of these!:
Astra Sport Hatch


Anyways, thanks for the replies, in real driving terms for her i dont think it would make any difference, but from a servicing point of view would it be worth it going for the discs all round?
Its mad, the entry level sxi model has discs all round and the next class up in spec which is the design has leather seats etc, but only discs on the front, strange!

alias no.9

It's already been said that the front brakes do almost all the braking but as a consequence of this, the brake shoes on rear drum brakes rarely need to be changed. I've had a few high milers and the only time I needed to do the rear shoes was when one of the rear calipers went, leaking brake fluid onto the shoes. IMHO, the suggestion of easier maintenance is pretty irrelevant because of this. I'd wager that the vast majority of people wouldn't be able to even tell the difference between the two. One thing to be said in favour of drum brakes is that when you leave the handbrake on when the brakes are warm, the cooling effect acts to increase braking force while the converse is true for disk brakes.

It's really down to a decision about the rest of the spec levels and the price of course.

JohnBoy

anecdotal eveidnce only, but from what I've heard, rear disks are more problematic than drums, I think largely due to the exposed nature of the handbrake acuation mechanisms.

plus some cars actually use mini drums built into the disks to provide the handbrake, so you have more parts to change potentially.

but they do look infinitely better than drums, especially the monsters you see on the back of octavias

mike65

ubu wrote:

Mike, its not that mumsy a car she's getting one of these!:
Astra Sport Hatch

God be with the days when 'yor ma' was happy with a Starlet!

Mike.

ciarsd

maidhc wrote:

I suspect the drive towards rear discs in cars over the past 5-8 years is down to the prevalence of alloy wheels (making the braking system visable), more than anything else.

I would not agree with that! far from it.

Drum brakes are an old system, disc brakes are a newer/more reliable & effective setup.

ciarsd

ubu wrote:

Mike, its not that mumsy a car she's getting one of these!:
Astra Sport Hatch

get your mumsy to get the Turbo VXR :cool:

Seth Brundle

Drums cost less to manufacture which is why some car manufacturers still use them - possibly the main reason!
My current car is the first with rear discs and they seem to require less effort. Cars with drums needed a bit more effort but that may just be my setup!

JohnCleary wrote:

Also cosmetic, car looks much nicer with discs at the rear.
They do make the ever so slight difference, but tbh I doubt your mother would be doing much high speed driving needing breaking-point stopping distances..

You could get the plastic replica thingys like this as they look really stylish:-

t5pwr

kbannon wrote:

You could get the plastic replica thingys like this as they look really stylish:-

Please tell me you are only joking...

Ernie Ball

Would look cooler with a caliper spinning around with the disc.:)

fletch

kbannon wrote:

Drums cost less to manufacture which is why some car manufacturers still use them - possibly the main reason!

Are you sure about that? I recently called my local dealership to get a quote for new drums and shoes (jus the parts now, not includin labour) and I was quoted around €350! (can't remember the exact figure) There is no way pads and disc would cost anything like that

Big Balls

The car in that picture is a VXR. I seriously doubt your mother is getting one. That's a bit like putting up a picture of a Golf GTI when you're buying a 1.4 Base Golf !!

fletch

Big Balls wrote:

The car in that picture is a VXR. I seriously doubt your mother is getting one. That's a bit like putting up a picture of a Golf GTI when you're buying a 1.4 Base Golf !!

Yeh but even the base SXI is quite sporty. I had one for a weekend during Opels million mile drive & it felt like a little sports car & was quite nippy.

Seth Brundle

fletch wrote:

Are you sure about that? I recently called my local dealership to get a quote for new drums and shoes (jus the parts now, not includin labour) and I was quoted around €350! (can't remember the exact figure) There is no way pads and disc would cost anything like that

Thats wrong.
Using my old E30 320i as an example and with prices taken from www.eurocarparts.com (OEM parts for most items (ATE))
Rear Disks £15.69
Rear Pads £16.99 set
Handbrake Shoes £17.03 (generally once off)
Rear Calipers £51.98 + (£20 if ABS)

Rear Drum £18.23
Rear Shoes £16.17
Rear piston £10.28

I believe that prices for pads & shoes are per set - all others is per side only. This also does not include the drum spring kit or similar items for the disk set up. These were taken from their website but the brochure is easier to fathom but Im too lazy to go into the next room and get it!

ubu

Big Balls, please accept my apologies, on further inspection i concluded that you were quite right, the picture of the car i posted was not the correct model to which i was referring to, i have sourced a picture of the sxi which i am posting now, sorry for any confusion.


Ciarsd, i think if i managed to convince her to get the VXR she would immediatly regret as she would never see the thing!

It basically boils down to more spec vs more brakes, if the design had disc brakes all round we wouldnt be having this conversation, she's not concerned with how the brakes look through the alloys, purely from a safety and practically POV.

fletch

kbannon wrote:

Thats wrong.

That's been your experience with BMW, mine was with Ford & I didn't imagine those figures

Squirrel

I find discs easier to work on

Big Balls

A mate of mine has an SXI. Nice car but sports car it ain't !

Am I wrong here lads or did I not see something saying the government were trying to force all manufacturers who want to sell new car in Ireland to have discs all round/ABS on their cars?

It seems a bit of a joke that Opel aren't providing all Astras with discs and ABS - are you sure about this?

ubu

I never said it was a sports car!

There is EU regulations regarding ABS now but nothing about discs.

heres a link to a PDF with the spec levels and technical data etc for the astra, on page 10 read the paragraph about the brakes.
http://a248.g.akamai.net/f/248/325/2h/www.opel.ie/content_data/GME/019/IE/en/GBPIE/pdf/newastra.pdf

ciarsd

ubu wrote:

Ciarsd, i think if i managed to convince her to get the VXR she would immediatly regret as she would never see the thing!

agreed ubu

greglo23

rear discs are ok but they do have real problems with the handbrake which usually needs a new caliper( expensive ) where drums are far simpler. lots of modern cars have abs and rear drums as the only difference is the sensor. in a previous model of the megane the abs teeth were on the discs and they rotted off from heat and corrosion which meant new discs or no abs !!

MrPudding

Can you have ABS with drums? I was looking at the spec of a car and it seemed to imply you could only have ABS with all round disks.

MrP

Seth Brundle

ABS is a modern technology (relatively speaking) and is better off with disks as part of a higher spec package but there isn't a reason why it couldn't be developed into the brake drum system. However, the nature of drum brakes wouldn't make it as good a system as disk ABS due to the mechanisms involved (springs, etc.). I can't think of any ASB drums in use though.
Have a look at this - excellent reference!
www.carbibles.com/brake_bible.html

greglo23

hundred of modern cars have abs and rear drums. all the drums and discs do is supply the braking effort. the abs system monitors each individual wheel speed by way of magnetic sensors and teeth on the moving part of the wheel unit. the abs control unit then limits the brake pressure to each wheel if it slows down more than the others. some cars with stability control will apply the brake without you pressing it at all if the computer senses the car beginning to go out of control !!! the only cars which dont usually have handbrake problems with discs are front handbrake cars like citroens or the older subarus.

Seth Brundle

Fair enough. i wasn't aware that it was available with drum models.
Every day is a school day!