RE: New brake discs could save lives
RE: New brake discs could save lives
Wednesday 23rd March 2005

New brake discs could save lives

Safety means fitting quality parts


Around 38,000 people are likely to be seriously injured or killed on British roads this year. Government research has found that one in three of all serious accidents are caused by the car simply being unable to stop in time, according to brake disc distributor, Carparts Direct.

Many manufacturers are fitting brake discs imported from China where labour rates and steel is cheap compared to Europe. Vehicle brake discs are not covered under a manufacturer’s warranty as they are a wear and tear item, like tyres and exhausts and since brake discs can wear in less than 25,000 miles, car dealers therefore benefit from charging a motorist for replacement.

Car manufacturers could fit performance brake discs that could improve road safety. Only a few prestige vehicle makers such Porsche and BMW fit drilled and grooved performance discs instead of standard discs – and only then to top of the range models. Almost all other vehicles on the road use the same old technology that has been fitted to cars for the last 20-plus years.

Improving the brake discs fitted to your vehicle could prevent an accident. When driving at speed and sudden braking takes place, you can experience brake fade. This is when your vehicle simply will not stop as quickly as it should. 

Brake fade occurs because the brake discs heat up. The hot surface of the brake disc glazes the friction material of the brake pads. In wet driving conditions the brake pads can lift from the brake disc. Stopping your vehicle can take twice as long. A third of all motorway accidents could be a result of ‘brake fade’ and could be prevented. 
 
UK manufacturer Rossini has developed a new range of specially multi-drilled and grooved performance brake discs. It is claimed the drilling cools the brake disc quickly. Grooves in the disc reduce brake pad glazing and repels brake dust and moisture, and help improve brake grip.

Titanium in the disc provides added strength and durability to prevent brake disc warping – the main cause of brake judder. Carparts Direct claimed that Rossini's discs can improve stopping distance by as much as 40 per cent. As with some other such products, the brake disc has the manufacturer’s logo embedded into the disc face so signs of uneven wear can be detected, and when the logo disappears the discs are down to minimum thickness – and legally in need of replacement. This is, said the supplier, an additional safety feature not used by any car manufacturers in the UK.

Mark Cornwall of Carparts Direct said: “The technology is well proven. Virtually all race and rally cars now run on drilled and grooved performance brake discs. Not only do the Rossini brake discs provide excellent stopping power for safer driving they look terrific too – and cost little more than dealers charge for a standard brake disc.”

Rossini supplies drilled and grooved performance signature discs for virtually every vehicle on the road – including family saloons, performance cars, 4x4’s, classic cars and of course competition vehicles. Prices start from around a £100 a pair.

www.carparts-direct.co.uk

Author
Discussion

Monkey Boy 1

Original Poster:

2,066 posts

248 months

Wednesday 23rd March 2005
quotequote all
Some people just ain't gonna part with over a ton in cash for brake discs for their "rep-mobile" when the original Factory fitted ones or aftermarket ones are cheaper.
The cars that would benefit from this & probably have the worst brakes of all are the 10 to 15 year old ones. But when the brakes cost 25 to 50% of the value of the car some people will say "why bother".

dannylt

1,906 posts

301 months

Wednesday 23rd March 2005
quotequote all
I haven't driven a really crap car for a while, but do you really get brake fade braking ONCE from high speed? I only ever got it on repeated braking on hilly roads (outside of circuit use obviously).

Plotloss

67,280 posts

287 months

Wednesday 23rd March 2005
quotequote all
Opinion is definately divided about drilled discs.

The place where I get the VX done said avoid like the plague...

annodomini2

6,952 posts

268 months

Wednesday 23rd March 2005
quotequote all
Never suffered brake fade problems on the road in my clio.

They're a lot more expensive than normal discs, last about the same, and wear your pads out faster!

leosayer

7,572 posts

261 months

Wednesday 23rd March 2005
quotequote all
I think poor braking is more likely to be caused by not changing the brake fluid for years on end, than brake fade. Or caused by people not braking hard enough.

How many cars don't have enough braking power to lock up the wheels if you really stamp on the pedal? If you can lock up the wheels then you have enough braking power.

cdp

7,871 posts

271 months

Wednesday 23rd March 2005
quotequote all
I haven't suffered brake fade in the Vectra on standard discs. I used to in the MR2, but had to be really going some to do it on the roads.

On the track is a different matter entirely where a couple of hard laps would finish them. In fact on the MGB we had a tendancy to slow the car down by throwing it into the corner sideways and not use the brakes at all!

I'm not keen on using competition pads on road cars as they generally need to get warm before they're effective. Not something you normally do on the roads.

jsr

1,155 posts

267 months

Wednesday 23rd March 2005
quotequote all
And don't forget that expensive brakes will have little effect if people use cheap budget tyres or remoulds.

Buying a set of performance tyres would surely be a more beneficial solution

FesterNath

652 posts

253 months

Wednesday 23rd March 2005
quotequote all
leosayer said:
If you can lock up the wheels then you have enough braking power.


Don't think that the above is true. Can see where you're coming from but having experienced the difference that larger brakes make on a mountain bike - where it is obviously a piece of cake to lock them up - I think that there's slightly more to it than that.

GreenV8S

30,956 posts

301 months

Wednesday 23rd March 2005
quotequote all
If your brakes get hot enough to need drilled discs then you definitely don't want drilled discs, use grooved discs instead. (Drilled discs are the work of the devil.)

Mr E

22,528 posts

276 months

Wednesday 23rd March 2005
quotequote all
I'm going 6 grooved vented discs on the Four.

And they're painfully expensive.

gooby

9,269 posts

251 months

Wednesday 23rd March 2005
quotequote all
If you just put these on the front then you would upset brake balance and potentially cause more trouble than you solve. Upgrade it all from the fluid to the tyres and all corners of the car. Surely it is more sensible to give more space on the road. Costs less and saves lives.

ATG

22,332 posts

289 months

Wednesday 23rd March 2005
quotequote all
It would be great if this were all true and if anyone can back up those claims with facts, I'd be happy.

But it sounds like a load of marketing bollox to me. 1/3 of all motoway crashes due to brake fade?? Where is the evidence to support that startling assertion? Or is it just that no data exists to disprove it? If that is the case I'm going to sell UFO jamming equipment because a third of all motorway crashes could be caused by Martians.

>> Edited by ATG on Wednesday 23 March 15:43

GreenV8S

30,956 posts

301 months

Wednesday 23rd March 2005
quotequote all
annodomini2 said:
Never suffered brake fade problems on the road in my clio.


Off topic, I've got one of these on loan at the moment. The brakes are stupidly sensitive, are they all like this?

ATG

22,332 posts

289 months

Wednesday 23rd March 2005
quotequote all
FesterNath said:

leosayer said:
If you can lock up the wheels then you have enough braking power.



Don't think that the above is true. Can see where you're coming from but having experienced the difference that larger brakes make on a mountain bike - where it is obviously a piece of cake to lock them up - I think that there's slightly more to it than that.


Better brakes may give you more feel and perhaps they might be less likely to snatch and lock the wheel. Certainly a locked bike wheel generates much less grip than a rolling wheel, so being able to stop it from locking when you're braking hard is key.

Nonetheless, if your braking system can generate enough torque to cause the tyre to break friction with the road, then simply being able to generate more torque on the wheel won't help you at all.

FesterNath

652 posts

253 months

Wednesday 23rd March 2005
quotequote all
ATG said:

FesterNath said:


leosayer said:
If you can lock up the wheels then you have enough braking power.




Don't think that the above is true. Can see where you're coming from but having experienced the difference that larger brakes make on a mountain bike - where it is obviously a piece of cake to lock them up - I think that there's slightly more to it than that.



Better brakes may give you more feel and perhaps they might be less likely to snatch and lock the wheel. Certainly a locked bike wheel generates much less grip than a rolling wheel, so being able to stop it from locking when you're braking hard is key.

Nonetheless, if your braking system can generate enough torque to cause the tyre to break friction with the road, then simply being able to generate more torque on the wheel won't help you at all.


So all these M3s etc. going around with massive brakes are acutally pointless, given that a 316i with big wheels will still be able to lock it's wheels?

ATG

22,332 posts

289 months

Wednesday 23rd March 2005
quotequote all
FesterNath said:
So all these M3s etc. going around with massive brakes are acutally pointless, given that a 316i with big wheels will still be able to lock it's wheels?
Near as damn it. For a one-off emergency stop (particulalrly if the car has ABS) I can't see how they can help at all.

ceejay

1,284 posts

271 months

Wednesday 23rd March 2005
quotequote all
But surely the M3 has wider tyres, probably a more grippy spec too so I can see the need for larger brakes. Also an M3 will do 150+ so has to have brakes that can haul it from that speed to zero safely.

Ceejay

havoc

31,956 posts

252 months

Wednesday 23rd March 2005
quotequote all
Plotloss said:
Opinion is definately divided about drilled discs.

The place where I get the VX done said avoid like the plague...


Drilling discs AIDS cooling and dissipation of pad material, but also weakens the structure of the disk...making cracking and ultimately failure more likely.

If you've got a car you take on track, AVOID drilled, go for grooved. But even there, so long as your car has ENOUGH discs (not 4, I'm talking about size!!!), and good-enough pads, mild track-use shouldn't hurt it...of course if you're tracking something like an M3 or a 4wd rally-refugee, then they're heavy enough to be a different matter...and you really have too much money to throw at tyres and brakes!!!


For road use, the need for drilled / grooved is largely cosmetic, and partly down to the ever-increasing weights of cars. Anything under 1,500kg shouldn't need drilled or grooved, they're a fair bit more expensive and won't make much difference over a good set of vented, heat-treated blanks.


REAL advice - go for better pads...Mintex 1144, Ferodo DS-2000 or -2500, Pagid (erm, forgot this one, sorry!) etc. Perfectly OK for an everyday road-car, better pedal feel, better retardation, shouldn't warp the discs (not THAT aggressive). Just lots more brake dust to clean off your alloys.

eddy_hyde

153 posts

292 months

Wednesday 23rd March 2005
quotequote all
Missing the obvious - fade!

yeah you can break traction once, but not 100 times

Which is why the M3 has bigger discs as
more disc = more pad = more surface area for heat dissipation=less fade=better brakes

Also weight transfer plays a part, as you brake the cars weight transfers to the front (same with acceleration to the rear), this is relative to the amount of deceleration (well tractive forces at the contact patch). So if you stamp on the brakes and brake traction, you get less weight transfer, so less braking capacity. However aploy smoothly at 100mph+ you can get a hell of a lot of weight transfer, and therfore more braking force possible, so bigger brakes become usefull, especially if you want to do it once. And manufacturers design for worst case conditions, ny fool in an old mini with drum bakes can lock the wheels if its damp with crap tyres, try it 4 up with luggage in the dry with good tyres and its a different story.

This is why big heavy cars (like a cayenne or RR) need massive discs, other than they look bling behing the chrome 20's

Oh and drilling, its a question of manufacturing methods, Porsche and other decent disc people like brembo cast the holes then clean them up, making them expensive. this means the material forms properly around the holes, making the discs stronger and less prone to cracking.

Its the cheapo halfords jobbies where they drill into cast material that causes problems, poor grain structure and expansion cracks around the stress raising holes.

They are much more expensive, but they do work, when done right, porsche dont do it just because it looks good!But on an average car they arent really needed

>> Edited by eddy_hyde on Wednesday 23 March 17:46

elderly

3,623 posts

255 months

Wednesday 23rd March 2005
quotequote all
I don't understand the physics of why drilled
discs help.
Grooves - allow the gas emmitted by the binder
of the friction material to escape;
but dilling reduces the mass
and surface area of the disc -
How does that help anything if the disc is already grooved????