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.
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".
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.
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.
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.
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
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.
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?
FesterNath said: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.
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?
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.
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
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