Brake discs

[morepower]

Loads of lads use the beringer iron disks racing supermoto and love them. Never heard of any problems either but plenty use braking wavy and braketech now too.

Super Moto is not as hard on discs with heat as a sportsbike at a trackday. It is the heat soak they get from braking from much higher speeds. wave discs are used in supermoto mostly because the MX boys are used to wave discs because they wipe dirt from the pads but this wiping at higher speeds also wears out pads very quickly when the discs are new... We started P3 supplying Supermoto and one of our first riders was Christian Iddon. They were running a set of pads per meeting but once they swapped to full circle discs they could run a set of pads for half a season. No difference in braking power over new wave discs but between 10 and 20% better than worn wave discs!

Sorry to sound a know all gent but as I said I have been involved in almost every form of motorsport as an engineer or racer and seen all the things the manufacturers do not want you to see. Like don't start me off on exhausts and how an Akropovic evo is supposed to be the same as the race teams run! If you saw the pipe on the Blue R1 at cadwell you would have seen what a real factory pipe looks like!!! Not listed in any Akro catalogue or even on the website!!!

[spacemonkey]

Loads of lads use the beringer iron disks racing supermoto and love them. Never heard of any problems either but plenty use braking wavy and braketech now too.

What a shame... I've always found cast iron discs to be really great and fully intended to get a set of PFM brakes at some point. I can't believe they are solid rather than floating!

Does anyone know of anyone who does produce floating iron rotors?

[morepower]

Sorry if I am missing something and this is a wind up......

NONE OF THE MAJOR BRAKE MANUFACTURERS USE CAST IRON ANYMORE!! THEY SUFFER FROM THERMAL SHOCK AND WEAR QUICKLY WITH THE MODERN HARD COMPOUND PADS!

Brembo and most of the others use a cast matearial that is a granular structured stainless steel and has none of the problems of cast iron but has a granular structure as good if not better than iron!

[spacemonkey]

Sorry if I am missing something and this is a wind up......

NONE OF THE MAJOR BRAKE MANUFACTURERS USE CAST IRON ANYMORE!! THEY SUFFER FROM THERMAL SHOCK AND WEAR QUICKLY WITH THE MODERN HARD COMPOUND PADS!

Brembo and most of the others use a cast matearial that is a granular structured stainless steel and has none of the problems of cast iron but has a granular structure as good if not better than iron!

No wind up as far as I'm concerned. I haven't tried every combination of braking surface out there so I have a fair degree of ignorance on the subject! ...I have only really tried OEM stuff and I've noticed that cast Iron discs seem to give a very nice feel and bite that has been lacking on other stuff. I assumed that cast iron had been shunned due to the aesthetics of the corrosion you can't really avoid getting.

[MonkeyJim]

What a shame... I've always found cast iron discs to be really great and fully intended to get a set of PFM brakes at some point. I can't believe they are solid rather than floating!

Does anyone know of anyone who does produce floating iron rotors?

spacemonkey - the PFM discs are floating. there is a carrier that bolts to the wheel, and then the disc attaches to that using a circlip.

in the pic of the wheel above you can't see the circlip as it runs on the inside face of the carrier, so whilst it might look like it's solid, it isn't.

Well, saying that, actually one of the discs is now solid - following the trackday abuse it locked solid, the disc no longer floats on the carrier.

I'm about to strip the wheel down to send it off to Dymag for a refurb, so I'll be having a look at the discs in more detail then.

I had high hopes for the PFM discs, and before they over-heated they were superb. Serious stopping power, which builds and builds over the course of a session as you get some heat in them. I was very impressed, for a whole morning.

But that's no good to me if they can't last a single trackday without problems. So for the time being I have reverted to the original set up.

As I said, maybe it's my fault for not sanding the discs sufficiently before using them.

[spacemonkey]

spacemonkey - the PFM discs are floating. there is a carrier that bolts to the wheel, and then the disc attaches to that using a circlip.

in the pic of the wheel above you can't see the circlip as it runs on the inside face of the carrier, so whilst it might look like it's solid, it isn't.

Well, saying that, actually one of the discs is now solid - following the trackday abuse it locked solid, the disc no longer floats on the carrier.

I'm about to strip the wheel down to send it off to Dymag for a refurb, so I'll be having a look at the discs in more detail then.

I had high hopes for the PFM discs, and before they over-heated they were superb. Serious stopping power, which builds and builds over the course of a session as you get some heat in them. I was very impressed, for a whole morning.

But that's no good to me if they can't last a single trackday without problems. So for the time being I have reverted to the original set up.

As I said, maybe it's my fault for not sanding the discs sufficiently before using them.

Ah, right.... So are there some dogs on the disc and carrier so it can slide, yet they don't rotate against each other?

I get the idea that the industry doesn't want to sell cast iron.... The question is if that is because of the material properties, or is it because of cost cutting or rust?

[fran9r]

Sorry if I am missing something and this is a wind up......

NONE OF THE MAJOR BRAKE MANUFACTURERS USE CAST IRON ANYMORE!! THEY SUFFER FROM THERMAL SHOCK AND WEAR QUICKLY WITH THE MODERN HARD COMPOUND PADS!

Brembo and most of the others use a cast matearial that is a granular structured stainless steel and has none of the problems of cast iron but has a granular structure as good if not better than iron!

Your quite right, they do, which is why PFM (and the pad manufacturers) strongly advise using only organic pads. It's nothing to do with 'modern' pads, in fact much of the development in track compound pads is on organic products.

I think Monkey is being fair, because effectively his discs are an unknown quantity being second-hand (I'm not knocking that at all, good on him). Although I've not had the delight, PFMs are definately still on my wish list.

As said, I really think the move to stainless is more for looks than for performance.

[MonkeyJim]

Ah, right.... So are there some dogs on the disc and carrier so it can slide, yet they don't rotate against each other?

I get the idea that the industry doesn't want to sell cast iron.... The question is if that is because of the material properties, or is it because of cost cutting or rust?

yes. instead of using the buttons that you normally see holding the disc to the carrier. A giant circlip holds the disc on.

I think stainless is so popular because it is shiny, and cheap to mass produce.

Your quite right, they do, which is why PFM (and the pad manufacturers) strongly advise using only organic pads. It's nothing to do with 'modern' pads, in fact much of the development in track compound pads is on organic products.

I think Monkey is being fair, because effectively his discs are an unknown quantity being second-hand (I'm not knocking that at all, good on him). Although I've not had the delight, PFMs are definately still on my wish list.

As said, I really think the move to stainless is more for looks than for performance.

I was using Performance Friction 95 compound pads. Don't know if they're organic, but they are recommended - by PFM - for use on iron discs.

Before mine went tits up, the PFM's were absolutely awesome in terms of stopping power.

[will#224]

Super Moto is not as hard on discs with heat as a sportsbike at a trackday. It is the heat soak they get from braking from much higher speeds. wave discs are used in supermoto mostly because the MX boys are used to wave discs because they wipe dirt from the pads but this wiping at higher speeds also wears out pads very quickly when the discs are new... We started P3 supplying Supermoto and one of our first riders was Christian Iddon. They were running a set of pads per meeting but once they swapped to full circle discs they could run a set of pads for half a season. No difference in braking power over new wave discs but between 10 and 20% better than worn wave discs!

Sorry to sound a know all gent but as I said I have been involved in almost every form of motorsport as an engineer or racer and seen all the things the manufacturers do not want you to see. Like don't start me off on exhausts and how an Akropovic evo is supposed to be the same as the race teams run! If you saw the pipe on the Blue R1 at cadwell you would have seen what a real factory pipe looks like!!! Not listed in any Akro catalogue or even on the website!!!

What disks do the phase one lads use? I was pretty sure it was a full beringer set up, iron alloy?

I dont think your a know it all, in fact please educate us some more....

[morepower]

What disks do the phase one lads use? I was pretty sure it was a full beringer set up, iron alloy?

I dont think your a know it all, in fact please educate us some more....

Not sure what the Phase one guys are using in terms of material. if they are sponsored they will say "off the shelf" anyway. But when they were using ISR many many years ago and ISR were still using cast iron Phase one used to send the ISR centres to a small engineering company in Derby called Derby Racing Services. I used to make the rotors for the ISR centres and we used to use some weird stainless steel plate material for the rotors.

As I was brought up round racing since I was about 3 years old I now ignore what is claimed to be fitted to the bike and look deeper into what they are actually using if I can. Like I said with BSB and WSB factory teams they have parts that look like ones sold but there is no way you or I could actually buy them. Yet they will still claim it can be built by anyone with the funds to build. The P3 Project bike was offered a set of Gas charged 25mm fork internals! GAS CHARGED!! But only the WSS600 teams were able to get them so I had to turn that offer down! The project bike had to be built with off the shelf parts! But there is so much out there that looks off the shelf or we are told it is off the shelf that it takes a good eye to know what you are looking at.

I have always said wave discs are not worth using and I almost had to eat humble pie when Ten Kate started using wave discs in WSB! But a few races later the trusty Brembo discs were back on the bikes!

The simple thing with discs is this...

Pads have to grip the disc material so how can a wave disc work better if there is less matal to grip?

The rotor material used does have to have a good coefficient of friction for the pads to bite onto so this is where cast has been better than the usual stainless steel plate used in cheaper discs and OEM. But it also has to be thermally stable and cast iron is brittle so a hot disc can crack if it is cooled or heated up very quickly.

Pad materials have changed and got harder with better friction properties and thermally more stable giving less fade. Cast Iron is not a strong material where the pads are concerned and Iron discs now wear too quickly with modern pads and organic pads are getting less and less common. Yes they have good initial bite but as the heat increases so does pad and disc wear. The pads retain a lot of heat and so do the discs which is not good for the brake fluid and seals but may be at the upper level of acceptable tolerences. But on track and used in anger this heat doesn't have time to dissipate and fade can be one of the first signs of this extra heat... Then followed by exessive disc expansion and increased wear and possibly warping to the hot disc. Now carbon based pads run at extreme temperatures with very little loss in power and as the carbon is not good at retaining heat less heat is passed back into the pad back and then into the calipers. SBS go one step further and actually use Stainless steel for the pad back to dissipate the heat even quicker!

If you look at the picture of the project bike take a look at the front disc. It is almost Black! We were setting up the bike at Mallory with the help of a top 5 600 super stock BSB rider and found we had a pad material problem which was causing the pads to "gas off" and give us some real brake fade. Not the lever coming back to the bar fade but the lever was still solid and the heated pads were giving off a gas from their structure and the bike wouldn't stop as we wanted. The heat was massive the discs were glowing red and the discs turned black when they cooled down. But as the pads we had were some new carbon compound and the stainless steel pad backs were losing heat quickly we still did not boil the brake fluid. This was quite extreme but with the levels of heat we produced a cast iron disc would have warped and as the disc wouldn't cool quickly the pads even with carbon and stainless back would have boiled the brake fluid. We swapped pad compounds and never had a problem again. With the project bike we pushed every part to it's limit and in some cases beyond. To get a GSXR600 capable of lapping the Nurburgring as quickly as we did was not luck it was very carefully planned out and nothing was taken for granted. If wave or cast iron discs work better than the ones we used then I would have used them... Trust me I would have used anything if I got even 1/10th of a second improvement during testing! We even spent a day playing with tyre pressures to gain any advantage!

[spacemonkey]

As I was brought up round racing since I was about 3 years old I now ignore what is claimed to be fitted to the bike and look deeper into what they are actually using if I can. Like I said with BSB and WSB factory teams they have parts that look like ones sold but there is no way you or I could actually buy them. Yet they will still claim it can be built by anyone with the funds to build. The P3 Project bike was offered a set of Gas charged 25mm fork internals! GAS CHARGED!! But only the WSS600 teams were able to get them so I had to turn that offer down! The project bike had to be built with off the shelf parts! But there is so much out there that looks off the shelf or we are told it is off the shelf that it takes a good eye to know what you are looking at.

So from that I take it you are saying we can't have the good stuff, the factories race on stuff that looks similar to what we can buy but isn't...... That's not a revelation to be honest.... The same goes for your comment about the fancy exhaust on the R1 at Cadwell. I think most of are interseted in getting best stuff we can although it is sometimes interesting to hear of the fantastic kit that can be manufactured but is withheld/unaffordable to the majority.

While the thermal properties and relatively brittle nature of cast iron certainly count against it, everything in engineering is always a compromise. Could it not be that cast iron rotors are a better compromise for the man who buys his own brakes, all things considedered?

Hopefully your brake discs should never heat up or cool fast. They are only ever cooled by air and even in racing they are usually used gently for a lap or so before they are really hammered.

Like a lot of this stuff, the information to close the argument is unavailable. Since John Robinson I've never heard of anyone doing any proper testing of friction material and publishing it for people like us to read about. The magazines normally prefer to recylce the bullshit they read in press releases.

[fran9r]

Pad materials have changed and got harder with better friction properties and thermally more stable giving less fade. Cast Iron is not a strong material where the pads are concerned and Iron discs now wear too quickly with modern pads and organic pads are getting less and less common.

This was quite extreme but with the levels of heat we produced a cast iron disc would have warped and as the disc wouldn't cool quickly the pads even with carbon and stainless back would have boiled the brake fluid. We swapped pad compounds and never had a problem again. With the project bike we pushed every part to it's limit and in some cases beyond. To get a GSXR600 capable of lapping the Nurburgring as quickly as we did was not luck it was very carefully planned out and nothing was taken for granted. If wave or cast iron discs work better than the ones we used then I would have used them... Trust me I would have used anything if I got even 1/10th of a second improvement during testing! We even spent a day playing with tyre pressures to gain any advantage!

Sorry I don't agree with the 'modern pads' bit. You match the pads to the disc material, end of. Organic compounds are still being developed, in softer compounds to increase the initial bite. With the correct pad were shouldn't be an issue.

All credit for producing the project bike, this is the type of special PB should be about. Did you actually compare lap times with iron discs and stainless (with respectice matched pads)? Thats the only way you will know for sure, but us mere mortals have budgets to stick too.

As a fan of the TT I note the number of PFM set-ups used by the privateer guys. That to me speaks volumes.

[2639]

A theory: Late 70's Jap disks did not stop you in the wet. Even with late 90's pads the brakes were not good enough [last time I rode ancient death traps in std condition]. Cast iron as an alternative worked better, and were fitted to bikes of some pedigree typically Italian, Laverda's, Guzzi's. Bmw's too I think. Various framed kitted bikes ran CI disks too. Has this resulted in a myth that CI disks are must haves, that even 30 years later still is considered true, even though its now 20 years or so since bike breaks got sorted?

I reckon the PFM circlip design is the most elegant. It would be cool if the design worked if the material specs were changed. But if it doesn't work...

I now have experience of 3 sets of ci disks from 2 manufacturers that suffer tyhe same problem; a rhythmic pulsing through the front end at certain deceleration rates. Pad scrubbing, solvent dousing, new pads all help for a bit... then its back, just as bad.

Sometimes its ok - light braking and occaisionally fairly hard is ok. But catch it wrong and the whole front end will judder hard enough to shake the thing to bits. You can feel the front wheel shudder build to the point I suspect the front could lock as weight is removed from the front end. Its a bit scary. Because of this the R1 has seen very little use. Has not been braked hard in yonks (all this year, end of last), and I cannot now trust a repeatable braking marker in case it goes bonkers on me. Trail braking has ceased.

One expensive school day is done. It's a right bastid when you spend your own cash, and the bits are shit.

I have some disks to try that are not CI. Good. One open mind will be installed and I will see if they are ok next week as Wed should see me on open pit at the GP track (fingers crossed) this has one 150 plus to hairpin every 2ish mins.

Failing that, I want the Beringer 4-quad system with ISR adjustable m cyls; should offer decent moment of inertia benefits from the disks and the levers can supply the powerful but squidgy-long feel I like.

Andy

[morepower]

While the thermal properties and relatively brittle nature of cast iron certainly count against it, everything in engineering is always a compromise. Could it not be that cast iron rotors are a better compromise for the man who buys his own brakes, all things considedered?

Hopefully your brake discs should never heat up or cool fast. They are only ever cooled by air and even in racing they are usually used gently for a lap or so before they are really hammered.

The cast iron issue has been sorted and the best compromise has been found the metal is still a cast material so that it keeps it's granular structure but it is a cast stainless. The OEM and cheaper discs are made from stainless steel plate which has a more smoothed out and uniform structure it is also cheaper to make discs from as the wastage is a lot less and the blanks can be cut out by lazer or water jet then finished machined and ground in large batches.

The race discs have to be cut from a solid bar of material which involves a huge lathe and a cutting tool parting off a thin section of bar which then has to be cut and machined to shape before being ground flat one disc at a time as the cutting process is not accurate enough to batch grind them once they have been machined. This is due to flex in the cutting tool which is about 5mm thick and can reach down deep enough into the bar to allow them to get a disc of metal. Grinding can only take small amounts off at a time and one disc .5mm thicker than another can wreck a whole grinding head if they do not raise the head enough for one thicker disc in a whole batch, so they have to do one at a time.

The heating up process for a disc can be very quick as a disc can be down at 100 degrees C at the end of a longer straight but braking into a tight corner can push the heat up well above 300 degrees C in about 2 or 3 seconds. This is quicker than putting it onto one of your cookers gas burners!

As for the argument about organics for pads or pad materials becoming harder there are still organic pads but even these have become harder to cope with the increasing performance of road bikes. We have seen OEM bikes needing new discs sooner than before due to disc wear. The steels used have not changed too much in the past 5 to 10 years but pads and their make up has changed drastically to cope with the demands of modern bikes. The pads we sell have seen changes in compounds gradually over the past couple of years and although they may sill be called SBS DC or EBC CFK or any number of other makes and specs, they have evolved and changed over the past few years. EBC DC (Dual Carbon) pads have become better at lower temperatures and although still not reccomended as a road pad there is less pressure for us to only sell to race licence holders! When I got the first batch of these from the distributor I was told I needed to see race licences before selling them! Now they are being sold along side road pads with dealers being reccomended to tell the customer track use only.

Here is a list of the current range of SBS pads...

http://www.sbs.dk/index.dsp?area=176

There is not one genuine organic pad in the whole range they are all either carbon based, ceramic or sintered. This goes for Bendix as well as they use SBS to make all of their pads. EBC are one of the few who have organics still in their line up and that will be changing in the not too distant future.

You pays your money you takes your choice.... but here is what I have found over the past 7 years as a brake component importer and distributor.

Wave discs....

New they work well but shread pads until the sharp edges have dulled.

Old. Pad wear is better but braking power is reduced by 10 to 20%.

New and old... Some extreme wave patterns can have a pulsing feel through the lever.

Cast Iron...

Faster wear due to the newer pad compounds and prone to warping in anything other than a genuine race disc which rings and rattles like a dry clutch. They need to really float due to the thermal expansion of the iron.

Plate stainless steel.

Lower friction properties than cast iron or cast stainless. Can be a bit more prone to warping in cheaper discs if the plate has not been heat treated and stabilised before being machined and heat treated before final grinding.

Cast stainless..

Higher rate of wear than plate stainless discs due to the more granular structure of the material.

If I am wrong then someone will come and prove me wrong I am sure......

[Cibbersicks]

Hey Rich, do you reckon the disc on the Bros was "Gassing Off" the other night? LOL

[morepower]

Hey Rich, do you reckon the disc on the Bros was "Gassing Off" the other night? LOL

Nah... That was just trigger "gassing off".....

They did get a bit warm though... I only did 2 stoppies and not that impressive ones either..... I recon after a good lap in the fast group I could have turned it a really nice shade of blue though....

[ronenige]

My twopenneth , when i worked for Devi's in the mid 90's they ran a pair of corsa's ( ducati's , not vauxhall ) which ran ci disc's , at the time the best available , but they were supposed the be changed every meeting iirc , expensive even for a BSB team

[spacemonkey]

The cast iron issue has been sorted and the best compromise has been found the metal is still a cast material so that it keeps it's granular structure but it is a cast stainless. The OEM and cheaper discs are made from stainless steel plate which has a more smoothed out and uniform structure it is also cheaper to make discs from as the wastage is a lot less and the blanks can be cut out by lazer or water jet then finished machined and ground in large batches.

The race discs have to be cut from a solid bar of material which involves a huge lathe and a cutting tool parting off a thin section of bar which then has to be cut and machined to shape before being ground flat one disc at a time as the cutting process is not accurate enough to batch grind them once they have been machined. This is due to flex in the cutting tool which is about 5mm thick and can reach down deep enough into the bar to allow them to get a disc of metal. Grinding can only take small amounts off at a time and one disc .5mm thicker than another can wreck a whole grinding head if they do not raise the head enough for one thicker disc in a whole batch, so they have to do one at a time.

The heating up process for a disc can be very quick as a disc can be down at 100 degrees C at the end of a longer straight but braking into a tight corner can push the heat up well above 300 degrees C in about 2 or 3 seconds. This is quicker than putting it onto one of your cookers gas burners!

As for the argument about organics for pads or pad materials becoming harder there are still organic pads but even these have become harder to cope with the increasing performance of road bikes. We have seen OEM bikes needing new discs sooner than before due to disc wear. The steels used have not changed too much in the past 5 to 10 years but pads and their make up has changed drastically to cope with the demands of modern bikes. The pads we sell have seen changes in compounds gradually over the past couple of years and although they may sill be called SBS DC or EBC CFK or any number of other makes and specs, they have evolved and changed over the past few years. EBC DC (Dual Carbon) pads have become better at lower temperatures and although still not reccomended as a road pad there is less pressure for us to only sell to race licence holders! When I got the first batch of these from the distributor I was told I needed to see race licences before selling them! Now they are being sold along side road pads with dealers being reccomended to tell the customer track use only.

Here is a list of the current range of SBS pads...

http://www.sbs.dk/index.dsp?area=176

There is not one genuine organic pad in the whole range they are all either carbon based, ceramic or sintered. This goes for Bendix as well as they use SBS to make all of their pads. EBC are one of the few who have organics still in their line up and that will be changing in the not too distant future.

You pays your money you takes your choice.... but here is what I have found over the past 7 years as a brake component importer and distributor.

Wave discs....

New they work well but shread pads until the sharp edges have dulled.

Old. Pad wear is better but braking power is reduced by 10 to 20%.

New and old... Some extreme wave patterns can have a pulsing feel through the lever.

Cast Iron...

Faster wear due to the newer pad compounds and prone to warping in anything other than a genuine race disc which rings and rattles like a dry clutch. They need to really float due to the thermal expansion of the iron.

Plate stainless steel.

Lower friction properties than cast iron or cast stainless. Can be a bit more prone to warping in cheaper discs if the plate has not been heat treated and stabilised before being machined and heat treated before final grinding.

Cast stainless..

Higher rate of wear than plate stainless discs due to the more granular structure of the material.

If I am wrong then someone will come and prove me wrong I am sure......

Interesting, thanks for the benefit of your experience here.....

I've always been suspicious of wave discs, this is why you have to be so careful when people tell you stuff. It is often hard to sift through all the bullshit. The level of myth and lies that surround motorcycles and motorcyle racing astounds me. You can trust almost nothing anyone says until you have gone and tested it yourself.

So who makes the discs from cast stainless material and are all discs made from cast stainless cut from billets as you describe? Presumably it is spun cast?

Yes, it is ridiculous that many road riders would want to buy pads that don't work at low temperatures. How thick can people be?

The temperature changes you describe do sound very violent. I suppose if this heat is all applied to the pad contact area it would stand a very good chance of creating distortion in any material. Are these changes you obseved in testing with data logging?

I would love to be in a position to test the best alternatives and fathom this out myself once and for all. Unfortunately I'm not! Also, the initial bite and feel makes a difference to confidence that is difficult to quantify or describe to others. This is something that should not be overlooked and it would be interesting to compare cast stainless billet rotors against cast iron alternatives. (With appropriate pads.)

[morepower]

Interesting, thanks for the benefit of your experience here.....

Yes, it is ridiculous that many road riders would want to buy pads that don't work at low temperatures. How thick can people be?

The problem is that pads had progressed so much... I know some know nothing of the way pads are rated and HH pads are just called HH pads to many, they do not realise the HH is it's rating for cold and hot performance. H is the highest rating so a pad rated a AH would be lethal when cold and great when hot and a HA pad would be the opposite. BUT and this is only my opinion. The ratings are now out of date as the SBS DC (Dual Carbon) pads are rated as HH pads! How can a pad that is rated at the highest friction rating still be classed as a race/trackday pad? I think the rating has changed with this pad as it may have been a lower cold rating at some point. But it is still not reccomended as a road suitable pad.

[spacemonkey]

The problem is that pads had progressed so much... I know some know nothing of the way pads are rated and HH pads are just called HH pads to many, they do not realise the HH is it's rating for cold and hot performance. H is the highest rating so a pad rated a AH would be lethal when cold and great when hot and a HA pad would be the opposite. BUT and this is only my opinion. The ratings are now out of date as the SBS DC (Dual Carbon) pads are rated as HH pads! How can a pad that is rated at the highest friction rating still be classed as a race/trackday pad? I think the rating has changed with this pad as it may have been a lower cold rating at some point. But it is still not reccomended as a road suitable pad.

The system of rating brake pads seems ridiculous. How can you have a pad that works best at high and low temperatures? It seems ridiculous that you can make one compound do everything. If this is the case then why is there more than one compound available? If this were possible then one pad would be suitable for road riders, track days and WSB!

This seems to be just another example of dumbing down which is all too familar. What we need is something more like a graph of braking torque against temperature for a certain clamping force.

The pad manufacturers seem to have moved away from the two letter system anyway don't they?

[morepower]

The system of rating brake pads seems ridiculous. How can you have a pad that works best at high and low temperatures? It seems ridiculous that you can make one compound do everything. If this is the case then why is there more than one compound available? If this were possible then one pad would be suitable for road riders, track days and WSB!

This seems to be just another example of dumbing down which is all too familar. What we need is something more like a graph of braking torque against temperature for a certain clamping force.

The pad manufacturers seem to have moved away from the two letter system anyway don't they?

They have to put the 2 letter reference on all pads even if it is not made a big thing of, the letters are there on the pads usually printed or stamped on the back.

As I said the levels for the rating seem to be out of date as the difference between the letter ratings is quite noticable but once you get to H ratings there is now a huge difference between a road biased HH pad and a race HH pad, yet they both meet the minumum H rating for both hot and cold!

[will#224]

Has anyone heard of or used the Ferodo disks?

[fran9r]

Has anyone heard of or used the Ferodo disks?

Seen them -excellent stuff, don't know about actual performance though. Ferodo are very under-rated, and supply as OE.

[will#224]

Seen them -excellent stuff, don't know about actual performance though. Ferodo are very under-rated, and supply as OE.

I really rate there pads, i was looking through there site and noticed the disks. They seem to work closely with Brake tech, the American company that does the carbon ceramic matrix disks and the like.

I was quoted £300 per disk for the brake tech stuff. Might buy some of them with my christmas bonus.

[andysp1]

i know this is a bit late but ill tell you anyway.I wanted new discs and saw some wavy ones on ebay,£a20 for both.I bought them and the were warped,guy sent me over a replacement pair and they were the same.The guy gave me the money back but is not bothered about me keeping the wavy discs,so i now have 2 pairs of worthless wavy discs sat in me garage!!finaly got factory ones,better then any replacment ones i recon.

[will#224]

i know this is a bit late but ill tell you anyway.I wanted new discs and saw some wavy ones on ebay,£a20 for both.I bought them and the were warped,guy sent me over a replacement pair and they were the same.The guy gave me the money back but is not bothered about me keeping the wavy discs,so i now have 2 pairs of worthless wavy discs sat in me garage!!finaly got factory ones,better then any replacment ones i recon.

Could they be skimmed?

[matt_the_blat]

A question for Morepower:

If I came to you for some replacement discs (or discs and pads) what would you sell or recommend to me?

02 Aprilia RSV-R - stock Brembo 4 pad calipers but with Braking wavy discs and Bendix MRR pads. Let's say it's for fast road riding (but sometimes slow road riding/commute, and a trackday now and then). Budget? Not too much more than if, say, I went for EBC so maybe £400-500 max.

Previous owner had the discs fitted after the OEM Brembo ones warped (very common). Not keen on them myself in terms of either form or function so seriously considering a change.

PDQ (who are local to me, highly regarded and know their Aprilias) do Brembo and Galfer, but as I wouldn't want wavy discs anyway I suspect they'd recommend Brembo aftermarket discs.

Any thoughts?

Cheers,

Matt

[morepower]

A question for Morepower:

If I came to you for some replacement discs (or discs and pads) what would you sell or recommend to me?

02 Aprilia RSV-R - stock Brembo 4 pad calipers but with Braking wavy discs and Bendix MRR pads. Let's say it's for fast road riding (but sometimes slow road riding/commute, and a trackday now and then). Budget? Not too much more than if, say, I went for EBC so maybe £400-500 max.

Previous owner had the discs fitted after the OEM Brembo ones warped (very common). Not keen on them myself in terms of either form or function so seriously considering a change.

PDQ (who are local to me, highly regarded and know their Aprilias) do Brembo and Galfer, but as I wouldn't want wavy discs anyway I suspect they'd recommend Brembo aftermarket discs.

Any thoughts?

Cheers,

Matt

OK.... Now I have only just found out after 7 years of dealing with ISR that their custom made discs (£200+ per disc) are not the only ones they do... they have OEM spec ones which are about £260.00 per set! Now these are the same material as their race discs, just made to match OEM spec calipers and fitting. The pads I would use are the SBS HF compound for road use I think the MRR are almost the same as the HF compound and the MCR are the same as the DC pads SBS pads (both brands made in the same factory) . Andy used the HF pad over the DC compound through choice at the Nurburgring.

The second option are the Brembo HPK discs but these alone are close to the upper limit of you budget if you include either Brembo or SBS HF pads. The Brembo discs are very good and better than OEM Brembo discs.

Brake tech are also very good but finding a UK dealer is hard. Their Axis Iron rotors are supposed to be good and although they are "Iron" they are ductile iron which is better than the old cast iron discs but they are still a compromise over rolled steel as used in the Brembo HPK and ISR discs.

Brembo are used by the top teams for a reason so their race products are very good but quite expensive.

Not sure what to say about Galfer brakes... I have had a few words with Sergio from Galfer on another forum and mentioned all the problems we have seen with wave discs. But he only got defensive and offered no proof of his claims even though he said he had proof I was wrong and was going to post it up. He has almost stopped posting on there now and has not been giving any advice for quite a while.

[matt_the_blat]

Thanks for the info morepower - much appreciated

I'll have a think on that and PM you if I want to place an order. Out of interest is there any reason not to keep using Bendix pads with either ISR or Brembo discs?

I had a look on the ISR website and couldn't see anything specifically for my bike but I'm fairly certain they're the same as some 748/916/999 Ducatis I would imagine they already make something suitable for my bike though and I gotta say that at £260-ish a set that's mighty mighty tempting

For what it's worth I had a look over on Apriliforum.com and found a few guys there who use and rate Brake Tech Axis iron rotors, albeit in the US. I also looked for Brembo and discovered they do various different discs but I spotted the Brembo HPK and thought they might suit my needs and budget.

Galfer = wavy discs =

Couple of issues to investigate first though before I splash out on new discs:

On both calipers the inside pads (i.e. nearest the wheel centreline) wear much quicker than the outside ones. Bear in mind these are 4 pad calipers - the fact that all 4 inside pads wear at the same rate, but much quicker than all 4 outside pads seems like too much of a coincidence to be a stuck piston (I clean and lube the pistons when I change pads anyway).

Could be the ghastly Braking wavy discs. I've heard of some Mille's needing shims/spacers between the disc and wheel but I think that's only if you retrofit radial calipers from later models though.

I'm going to try cleaning the calipers and replacing the caliper piston seals & dust seals (only KTM sell these Brembo bits though!) so I'll see what that does for me and then I can think about new discs.

Cheers,

Matt