Brembo or Galfer?

[alickswud]

I've a 2010 796 non ABS with what seems to be warped discs, i've spun the bobbins with brake cleaner and the lever is still pulsing.

The question is do i go for Brembo Oro or Galfer Wave as a replacment?

Thanks

[Mr Gazza]

I put two Arashi waves on mine. For the price of one of any that you mentioned.
Rather good discs too!

[iainw]

When mine warped on the S4r I put EBC wavey ones on, they have bobbins that won't jam up. I'm very happy with them.

https://ebcbrakes.com/articles/sd-system-square-drive-and-how-it-works/

[Luddite]

Just out of interest, did you get an advisory at MOT time about a "fluctuation of braking effort"?

I had Galfers on my S2R http://www.ukmonster.co.uk/monster/showthread.php?t=55219

Coupled with four pad Brembo calipers, they performed perfectly. The wave design is supposed to aid cooling and so resist warping but then the fully floating Brembos are also supposed to be warp resistant.

I don't think you'd detect any difference in performance between the two in normal road riding so it probably comes down to which design you prefer.

To be honest, I chose mine on looks rather than any consideration of performance.

As Mr Gazza and Iain have shown, there are a number of manufacturers producing wavy discs, so you don't have to restrict yourself to just Galfer. If you do go for Galfer, I'd recommend Calsport as a supplier; great service and reasonable prices. https://calsport.co.uk/ducati-monster-796-2010/categories/brakes-and-wheels/galfer-front-wave-disc-each-weight-1325-g/dc807w

[utopia]

I've had four or five mot advisories about my front discs having "fluctuation of brake effort".
It was completely unnoticeable at any kind of speed, but led to an annoying pogo effect when using the brakes gently in slow traffic queues etc.
I checked them and they weren't in the least bit warped.
I cleaned the bobbins thoroughly and I abraded the surfaces with fine wet and dry.
Minor improvement, but not a lot.
Then I did a trackday and they seemed a little better afterwards so I made a point of giving them some hard use from time to time.
Since then they have gradually got better and now there is no sign of pulsing whatsoever, at even the lightest touch on the lever and at walking pace.

I also try not to leave the bike standing with wet pads in one position for too long.

In summary, new discs are probably the most effective way to eliminate an annoying problem, but I'd wager that your old discs can be brought back to proper function .. but the process is a bit uncertain.
It also requires patience and putting up with the pulsing in the meantime.

[slob]

Just out of interest, did you get an advisory at MOT time about a "fluctuation of braking effort"?

I had Galfers on my S2R http://www.ukmonster.co.uk/monster/showthread.php?t=55219

Coupled with four pad Brembo calipers, they performed perfectly. The wave design is supposed to aid cooling and so resist warping but then the fully floating Brembos are also supposed to be warp resistant.

I don't think you'd detect any difference in performance between the two in normal road riding so it probably comes down to which design you prefer.

To be honest, I chose mine on looks rather than any consideration of performance.

As Mr Gazza and Iain have shown, there are a number of manufacturers producing wavy discs, so you don't have to restrict yourself to just Galfer. If you do go for Galfer, I'd recommend Calsport as a supplier; great service and reasonable prices. https://calsport.co.uk/ducati-monster-796-2010/categories/brakes-and-wheels/galfer-front-wave-disc-each-weight-1325-g/dc807w

I have the same setup on my 1000 and constantly got advisories for the discs pulsing, I even bought another set of discs since it's impossible to check wavy discs with a dial guage. I swap the pads over from one side to the other before an MOT now, they sail through and 30odd miles later when they've bedded in again the low speed grabiness returns. They do however work faultlessly as tested braking from 135mph at the end of the park straight. Plus one for Calsport's service.

[Luddite]

Just a quick tip if you do fit wavy discs, you should stagger the left and right discs so that, if you're looking at them from the side, the peak of one lines up with the dip in the other. They don't have to be exactly opposite, but what you want to avoid is having two peaks exactly opposite one another. The idea of this arrangement is to prevent fluttering at the lever.

Oh, and whichever discs you choose, order a new set of disc bolts. They are a critical item and it's good practice to replace them for safety. Also, the original bolts will be loctited in place and you can almost guarantee that at least one will get chewed up during removal!

[slob]

Just a quick tip if you do fit wavy discs, you should stagger the left and right discs so that, if you're looking at them from the side, the peak of one lines up with the dip in the other. They don't have to be exactly opposite, but what you want to avoid is having two peaks exactly opposite one another. The idea of this arrangement is to prevent fluttering at the lever.


Interesting (he says on his way to the garage to check)


Oh, and whichever discs you choose, order a new set of disc bolts. They are a critical item and it's good practice to replace them for safety. Also, the original bolts will be loctited in place and you can almost guarantee that at least one will get chewed up during removal!

I always warm the hub, to soften any loctite before attempting to remove disc bolts

[utopia]

Interesting (he says on his way to the garage to check)

I always warm the hub, to soften any loctite before attempting to remove disc bolts


Yes, I hadn't heard that before, but I guess it makes sense.
So ... were they ?
Mine are not wavey, so that wasn't the cause of my earlier pulsing.

Definitely warm the hub .. and/or the bolt heads.
Not only will it help prevent chewing the heads but more importantly, it will protect the threads in the soft, ally hub from getting damaged by the residual Loctite as the bolts are removed.

[iainw]

Just out of interest, did you get an advisory at MOT time about a "fluctuation of braking effort"?[/url]

Yes, but it wasn't noticable under normal braking so I kept riding... untill I went hooning into a bend a little (lot) too fast and had to scrub speed at an alarming rate. The lever pulsed like mad and surprised me, so I let it go and leaned at an angle and speed I'd never been at before. :shocked::shocked::shocked:

Got home and ordered an new pair of discs and underkeks.

[slob]

they were lined up...
however, with 6 holes (unlike s2r), 9 bobbins & 18 petals it's not possible to fully stagger them, I have rotated one so the slots aren't lined up and will report back when they're bedded in again (it's mot week)
annoyingly, of course, the carriers are now staggered, so if it makes no difference they'll be going back to aligned

[Luddite]

they were lined up...
however, with 6 holes (unlike s2r), 9 bobbins & 18 petals it's not possible to fully stagger them, I have rotated one so the slots aren't lined up and will report back when they're bedded in again (it's mot week)
annoyingly, of course, the carriers are now staggered, so if it makes no difference they'll be going back to aligned

I guess I'd better apologise in advance in case this makes no difference. I'd hate to think you went to all this trouble for nothing because of something I wrote!

Fingers crossed! :on:

[Mr Gazza]

My discs are lined up, carriers and waves. I get no pulsing what so ever.

Further to your comments on the disc bolts... Don't try and use stainless bolts in this application. They will not take the torque required. Either A2 or A4 it makes no difference, you need a very special grade.
I used plated steel in the end... No worries.

[alickswud]

I have lots of pulsing on the brake lever, coming to a halt is a right pain at the moment.

I'm not too keen to put anything cheap on it as I value being able to stop.

Has anyone used the TRW lucas discs, they look quite interesting?

[Flip]

Yes, but it wasn't noticable under normal braking so I kept riding... untill I went hooning into a bend a little (lot) too fast and had to scrub speed at an alarming rate. The lever pulsed like mad and surprised me, so I let it go and leaned at an angle and speed I'd never been at before. :shocked::shocked::shocked:

Remember the old adage- if you've got enough grip to brake in a bend you've got enough grip to get round the bend without braking (whether or not you have enough road depends on your line into it of course :chuckle:).

As for disc bolts I got some lovely shiny Titanium ones a while back for my 900 when it was refresh time.

http://i1372.photobucket.com/albums/ag329/fluke900/IMG_4008_zpsjbmec3kf.jpg (http://s1372.photobucket.com/user/fluke900/media/IMG_4008_zpsjbmec3kf.jpg.html)

[jerry]

I use Galfer on the M750 7 years and Arashi on S4 6 years both are excellent and much longer wearing than crummy warping brembo ones

[Darren69]

I've not had any problems with the Brembo disks on either of my Dukes, the 748 is on the original steel centered half moon style and have done over 20,000 miles and the S4 has the snowflake type and 7500 miles no problems. I'm wondering if the people who have had issues have been on track and something has stopped the rotors expanding under hard use (a buildup of brake dust/crud on the bobbins because you don't use the brake that hard in normal road use and there should be enough free play for the rotor to expand without distorting.

Now the old solid Brembos with bolted cast iron rotors like on '70's/80's Lavs/BM's/Guzzis etc, they did tend to warp but they were solid mounted on the carriers. I've had a few of these go on me.

As for disk bolts I have stainless ones atm with the low head which I was lead to believe are specifically for disk mounting, again no issues but I do have some titanium ones to fit the Brembo Clubman fully floating disks I have on the monster at some point in the near future.

These bad boys:-

http://www.ebay.co.uk/itm/361497172085?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

There is so much float in those I can't imagine they could warp however hot they got. They do rattle quite a bit like the clutch does though. :)

[slob]

After a problem free MOT and 200 miles the low speed pulsing is back (Galfer discs & Galfer sintered pads) braking at speed is still faultless. I'll be swapping back to the 'balanced' look at some point.

I also did a full hydraulic fluid transfusion and the clutch fluid is black again already.

[Darren69]

After a problem free MOT and 200 miles the low speed pulsing is back (Galfer discs & Galfer sintered pads) braking at speed is still faultless. I'll be swapping back to the 'balanced' look at some point.

I also did a full hydraulic fluid transfusion and the clutch fluid is black again already.

Are you using an aftermarket clutch slave? I've noticed mine stays cleaner for a bit longer with one.

[utopia]

Hmmm .. I wonder what the effect would be if you rotated one disc by 180 deg ...?
Basically, I'm wondering if the grabbiness relates to the same point on both discs, or whether its just one that's the problem.
If both discs grab at the same point, that might give some clues as to the origin of the problem.
This would be characterised by the frequency of the grab doubling after one disc was rotated 180 deg. Perhaps that would be noticeable ...?
Arguably, it should also halve the effect at each grab .. which might make things more acceptable.

If all the above isn't total balderdash then it might suggest that the grabbiness is caused in the first place by the calipers, not the discs as such, possibly by locally degrading the surface after holding pads against hot stationary discs for too long, or maybe corrosion effects from being parked up with wet pads.

If you've got to move one disc anyway, it might be worth trying it for the experiment if nothing else.

[Darren69]

Isn't pulsing inherent in the design of the disks? Wavy disks present varying amounts of metal to the pads on which to bite rather than a uniform surface of normal disks.

[iainw]

EBC wavy disks offset half a wave, no pulsing.
http://i1177.photobucket.com/albums/x343/iainwa/8Disks.gif (http://s1177.photobucket.com/user/iainwa/media/8Disks.gif.html)

[utopia]

Isn't pulsing inherent in the design of the disks? Wavy disks present varying amounts of metal to the pads on which to bite rather than a uniform surface of normal disks.

That does make some kind of sense, particularly if you look at the variation in width of the waveys in the above pic.
BUT, with 10 waves per disc, any resultant pulsing would be at 10 times the frequency of that caused by a single surface degradation spot or, for that matter, by a single warping distortion or sticky bobbin.
I'm guessing that would be too fast to notice .. although for purism sake I might still offset them if I had waveys.

I really can hardly believe the improvement that my discs have undergone, and its been a lasting improvement too, for 2 or 3 years now.
Now I can trickle up to a traffic queue at almost falling-over speed, one finger gently caressing the brake lever, left foot snicking neutral at the last minute, while my right foot can hover ready to dab down, rather than being occupied with trying to be gentle on the rear brake, which is less than easy to be gentle with in the first place anyway.
I can honestly detect no trace of pulsing whatsoever now.
Its transformed the bike in these conditions tbh.
Oh, and my discs are the thinner, 4mm ones, so you would think that they would be more prone to warping than the thicker ones.

I'm convinced that the pulsing is most often caused by some kind of localised degradation of the disc surface (rather than warping, or even sticky bobbins, though both may occur occasionally too), and it seems most likely that this local surface degradation would come from the calipers/pads.
Therefore I'm now very intrigued to know if the pulsing effect can be lessened by rotating one disc by 180 deg, as I suggested earlier.
I'm almost (but definitely not quite) looking forward to the problem returning, just so I can test out the theory.

[iainw]

I'm convinced that the pulsing is most often caused by some kind of localised degradation of the disc surface (rather than warping, or even sticky bobbins, though both may occur occasionally too), and it seems most likely that this local surface degradation would come from the calipers/pads.

From the link in my first post on the EBC web site..... Under the heat of braking a rotor blade expands or shrinks in both its diameter and band width causing the inside of the rotor blade to shrink radially inwards towards the hub. With circular buttons, as the rotor shrinks, it will contact the inner button and cause the rotor to tighten and either be distorted sideways causing either brake pulsation or spongy brakes.

I believe that the Brembo disks used on most monsters and many other bikes are the most common in failing in this way, A Guzzi I had some years ago went the same way and there were many reports on the Guzzi forum of others suffering this, all with the same rotors. We don't seem to hear of this with other brands of disks on other bikes.

[utopia]

Sorry, I didn't read the link at the time .. I will do, but don't have time just at the moment.

However I would say that, although that sounds like a valid scenario to explain warping, it doesn't explain how my previously pulsing discs are now cured.
In any case, the expansion that they describe will always occur and should be allowed for in the clearance in the bobbins anyway.
Furthermore, I wonder why the disc would distort under those conditions rather than the much softer carrier ..?

I'm not saying that it doesn't happen, or that "warped" discs don't exist.
But its an easy and obvious claim to make and I suspect that it is therefore frequently misused as a diagnosis.
This is only made worse when new discs are seen to cure the problem, seeming to back up the analysis.
Customer goes away happy, but poorer. Dealer is happy to have sold a pair of new discs. Everybody's happy. and so the myth persists.

Just my own considered view of course.
I can't prove it ... yet. ;)

[BLUNT]

From the link in my first post on the EBC web site..... Under the heat of braking a rotor blade expands or shrinks in both its diameter and band width causing the inside of the rotor blade to shrink radially inwards towards the hub. With circular buttons, as the rotor shrinks, it will contact the inner button and cause the rotor to tighten and either be distorted sideways causing either brake pulsation or spongy brakes.


EBC are talking complete NONSENSE - the inner radius expands outwards as it is heated, it does not shrink inwards.

This is schoolboy physics lesson.

[Darkness]

EBC are talking complete NONSENSE - the inner radius expands outwards as it is heated, it does not shrink inwards.

This is schoolboy physics lesson.

Agreed: that's also why you heat housings and freeze bearings to get them into the hole easier.

[Darren69]

EBC are talking complete NONSENSE - the inner radius expands outwards as it is heated, it does not shrink inwards.

This is schoolboy physics lesson.

Schoolboy physics and marketing BS and I fail to see any advantage of wavy disks besides some gyroscopic weight saving and fashion in the first instance.

If there were any advantages that outweighed standard style full floaters wouldn't the race teams all be using them? I'd like to see some quantitative evidence that supports these supposed claims.

[utopia]

Ha .. of course they are (talking nonsense).
Funny how you can get drawn in to accepting complete tosh sometimes, eh ?
Slightly embarrassed at my gullibility, but hey ho.
Thanks for the correction.

[Darren69]

Actually the supposed perceived weight saving is not always true, I've just read that most wavy disks are made much thicker than standard disks in order to retain the strength of regular disks. So they are not always lighter and are in fact sometimes heavier!

[jerry]

It has been suggested that wavy discs run cooler due to bigger frontal area of the wavy parts maybe more marketing tecno B/S

[Darren69]

That may be true, I think the cooling affects of the air are maybe slightly improved, but the thin parts of the disk are going to get much hotter initially than the thicker parts, at least until the heat dissipates. It seems to me that they would develop local hot spots on the thinner sections, so they might be hotter initially and more efficient and that benefit would also mean less local heat transfer to the calipers which is no bad thing, but since there is less heat sink (metal) area they would cool much slower in theory too!

[Dukedesmo]

Actually the supposed perceived weight saving is not always true, I've just read that most wavy disks are made much thicker than standard disks in order to retain the strength of regular disks. So they are not always lighter and are in fact sometimes heavier!

I have also heard the claim of better heat dispersal due to the increased circumference but don't know if it really makes much difference?

But I agree that, all else being equal, a round disc 'must' be better. That said I have wavy style discs on the rear of my Monster and 916 but I did this primarily for weight reduction (they're both lighter than the originals) not brake performance increase.

[utopia]

Tongue in cheek, my mate suggested a possible cause for pulsating discs.
In the same way that old window glass is claimed to get thicker at the bottom over long periods of time (probably a myth, but anyway...) he reckons that if you leave your Ducati parked up for too long without using it, the discs get thicker at the bottom as the material "cold-flows".
Worth sharing, I thought. :toilet:

In the same conversation (but being serious now), we decided that it might be useful to isolate one disc in a twin disc set-up, in order to see if both were pulsing or just one.
Even better perhaps, if you could then somehow test to see whether two pulsing discs were pulsing at the same time, or out of phase.

I'm almost disappointed that mine are cured, because I've lost the option to test.

[Darkness]

This reminds me of the '70s debate about whether drilling brake disks improved cooling of the disks and pads, whether that was a good thing, and whether it aided wet weather braking.
As then, I suspect it makes less difference than the choice of pad and disk materials?

[Darren69]

Tongue in cheek, my mate suggested a possible cause for pulsating discs.
In the same way that old window glass is claimed to get thicker at the bottom over long periods of time (probably a myth, but anyway...) he reckons that if you leave your Ducati parked up for too long without using it, the discs get thicker at the bottom as the material "cold-flows".
Worth sharing, I thought. :toilet:

In the same conversation (but being serious now), we decided that it might be useful to isolate one disc in a twin disc set-up, in order to see if both were pulsing or just one.
Even better perhaps, if you could then somehow test to see whether two pulsing discs were pulsing at the same time, or out of phase.

I'm almost disappointed that mine are cured, because I've lost the option to test.

Wouldn't a DTI clamped to the fork leg and spin the wheel, be the easiest way to check for any runout?

[Darren69]

This reminds me of the '70s debate about whether drilling brake disks improved cooling of the disks and pads, whether that was a good thing, and whether it aided wet weather braking.
As then, I suspect it makes less difference than the choice of pad and disk materials?

I remember (just) in the '70's the Japs gave us shiny chrome plated brake disks which didn't work very well in the dry but in the wet didn't work at all. I think drilling them gave somewhere for the water to run off! :)

[utopia]

Wouldn't a DTI clamped to the fork leg and spin the wheel, be the easiest way to check for any runout?

Yes, but if it isn't runout .. but instead is due to localised variations in the surface conditioning .....?
This is my best guess at the cause of most "warping" issues, but it obviously wouldn't show up on a dti.

[jerry]

in the 70s my guzzi and nortons would stop in the wet due to rusty cast iron discs but the jap bikes would not stop at all with shiny chrome discs and the jap tyre would last forever as they were made of nylon but were lethal in the wet

[utopia]

I remember the Japanese discs well .. but they weren't chrome.
I'm not sure exactly what they were, but it was some form of stainless steel.

To the best of my knowledge, modern discs are made from martensitic stainless steel .. an uncommon form which is identifiable by being magnetic.
Maybe old jap discs were made of the more common ferritic or austenitic stainless steels .. which have better corrosion resistance.

[Darkness]

I remember the Japanese discs well .. but they weren't chrome.
I'm not sure exactly what they were, but it was some form of stainless steel.

To the best of my knowledge, modern discs are made from martensitic stainless steel .. an uncommon form which is identifiable by being magnetic.
Maybe old jap discs were made of the more common ferritic or austenitic stainless steels .. which have better corrosion resistance.

Definitely not chrome on Honda as you could skim them. Didn't rust particularly, so some form of stainless. I remember the trick was to keep applying the brake to keep them warm: forget that when it's cold and wet and you'd get a big handful of nothing, followed by a locked front wheel when they did clear the water.

Happy days......sometimes I wonder how I survived?

[barynson]

Not a fan of Brembo. They have a tendency to warp easily.