Norge front brake calipers(merged topics)

[Bison]

Greetings from a wet and windy Scotland.
Some may remember me having a problem with my brakes on my Norge pulsing on the front?., well, the solution was found, after replacing the discs unfortunately!.
I fitted the new discs, and pads, and thought the pulsing had gone, but after some miles it was starting again, you could just feel it, then however, as the miles were added, it got worse.
I was doing my IAM course and practising emergency stops, a while after this I noticed the brakes pulsing, then I asked on the forum and got lots of good replies, but really nothing I hadn't already done.
The callipers were slightly worn obviously, after almost 70K miles, my emergency stops had caused what was probably an already slightly larger gap between the disc pad steel backing and the aluminium of the calliper to get much bigger, in fact creating a u shaped groove on the top, load bearing part of the caliper. When the pads were new they were fine, and when the disc was at it's thickest (new) it was fine, as they bedded in the pad would slide into the groove when the brakes were applied and not move any further, at the bottom of the calliper of course the pad would close up fine, this caused the pad to tilt on and off as the pad moved around in the calliper. This wasn't apparent at the beginning, but became glaringly obvious when I closely inspected the callipers.
So, there you go folks, a new one on me, anyone had this before?. I hope it will shed light on someones problem and help.
Please now see my next post!
Alan.

[Bison]

Me again.
If you read the previous post you will see I am in need of replacement front callipers.
They are P4 30/34. 65mm spacing. Now then, I can get a set of 65mm spacing callipers off a 2005 Multi `strada, which look like they are 30/34, but the seller doesn't know if they are. The outer castings look slightly different, but I looked at a Breva calliper for sale, it looks identical
My question, will they fit my 2007 Norge?. Are all P4 65mm created equal?. Are there different offsets?
Thanks.
Alan.

[Huzo]

Me again.
If you read the previous post you will see I am in need of replacement front callipers.
They are P4 30/34. 65mm spacing. Now then, I can get a set of 65mm spacing callipers off a 2005 Multi `strada, which look like they are 30/34, but the seller doesn't know if they are. The outer castings look slightly different, but I looked at a Breva calliper for sale, it looks identical
My question, will they fit my 2007 Norge?. Are all P4 65mm created equal?. Are there different offsets?
Thanks.
Alan.

A couple of questions.
What does 30/34 refer to ?
What does 65 mm spacing mean ?
What is “offset” as it applies to calipers ?
What’s wrong with your old ones ?

[Huzo]

I really do not understand the second half of your description.

[n3303j]

The backing plate on the brake pad has worn a groove in the caliper body. Now the backing plate hangs in this groove at the pad leading edge as the remaining portion of the pad pushes on to the disk causing uneven pad wear and erratic breaking.

Situation sounds like it could become dangerous. Last thing you need is any binding in a braking system.

Replace the caliper.

[Bison]

Sorry Huzo,
Yes, N3303J explained much better than I did. The steel backing plate on the pad hammered a groove in the aluminium of the calliper, the pad could move more than 3mm in the direction of rotation and would stick in the groove.
Alan.

[Bison]

Huzo,
Forgive me, I'm not doing too well with my posts today.
Brembo P4's are four piston callipers, the lower two pistons, one on each side, are 30mm diameter, the upper two pistons, one on each side are 34mm diameter.
The 65mm refers to the distance between the bolts which fix the calliper onto the fork leg.
The offset I was enquiring about is the position of the groove in the calliper that the disc rotates through, IE, when I bolt the calliper up will it foul the disc.
I'm assuming all the callipers of this era were the same, it's just that it could turn out to be an expensive assumption if they are not. The only Norge callipers I can find are double the price of the Ducati ones I was asking about. Do I take the chance?, I was hoping someone on the forum might know if the Ducati ones are the same as the Norge ones dimensionally.
Alan.

[Huzo]

Thanks mate, now I get it.

[Huzo]

Can you disassemble the caliper and have the groove filled, then dress it back to straight again ?

[Bison]

I think the only way to do that would be aluminium welding, and I think the heat would distort the calliper, almost certainly the holes for the pistons.
My only options are to buy new, or good used, I'll go with the latter if I can make sure all the callipers are the same. Almost every Italian bike manufacturer used them. The differences that I can find out about are mainly either 65mm or 40mm spacing for the mounting bolts, and I think there's a calliper which has  all the pistons 34mm.
I'll probably end up buying the Ducati ones, I'll report back.
Alan.

[Huzo]

I think the only way to do that would be aluminium welding, and I think the heat would distort the calliper, almost certainly the holes for the pistons.

Not necessarily if they are pre heated, but maybe.
Of course the bores can be reamed a thou’ or so to true them if required, it’s the seal that takes up the difference.
But anyway, good luck.

I would love to get the old ones if possible, I’d pay the postage or collect them next time I’m in the UK.
I’m still hazy as to how a brake can pulse due to a misplacement of a pad.
If the pad/disc combination grabs at the 12 o’clock position, what makes it free up at the 3 o’clock and 9 o’clock  position ?
Have you put a dial gauge on the disc and/or made sure the bobbins are fully free ?
There is no contaminant on the disc ?
Certainly the caliper issue needs addressing, but I wonder if that is the anomaly.
No matter what issue the pad has, if the disc is spinning truly through the gap, there should be no reason why the braking effect should vary around the course of it’s rotation.
It may very well be sub optimal, but not on/off to any degree…

[Bison]

The discs are brand new. When you spin the wheel you can hear a slight rustle as the pad touches the discs, but there's no appreciable run out on the disc at all. The pads are so loose they are moving around. My old discs had no real run out either, but I replaced them thinking that must be the problem, it wasn't.
I took a file to the calliper where the pad had beat a groove, I flattened it out to a fair degree, then refitted the pads, that immediately made a big difference, so I think I'm on the right track, well, there's really nothing left to check, wheel bearings, forks, head bearings, wheels, discs, everything checks out, I even checked the tyre for run out, it's perfect.
Alan.

[Huzo]

Well you’ve certainly applied good diagnostic techniques towards finding the problem. Most if not all of what I suggested has been covered.
Have you been able to ascertain if the pulse corresponds to the rate of rotation ?
If it does not pulse in unison with rpm, then my suggestions are a nonsense.

[rocker59]

Me again.
If you read the previous post you will see I am in need of replacement front callipers.
They are P4 30/34. 65mm spacing. Now then, I can get a set of 65mm spacing callipers off a 2005 Multi `strada, which look like they are 30/34, but the seller doesn't know if they are. The outer castings look slightly different, but I looked at a Breva calliper for sale, it looks identical
My question, will they fit my 2007 Norge?. Are all P4 65mm created equal?. Are there different offsets?
Thanks.
Alan.

Alan,

They should be identical.  Guzzi and Ducati have shared the same Brembo parts bins since the 1990s.

[Bison]

I'm happy to report that the callipers I bought, from a 2005 Ducati DS1000 Multistrada do indeed fit the Norge, and have cured my pulsing front brake problem.
Alan.

[Bison]

Brake pulsing fixed by replacing the front callipers, I am very happy to say.
Alan.

[Tom H]

Congrats

Tom

[Huzo]

I'm happy to report that the callipers I bought, from a 2005 Ducati DS1000 Multistrada do indeed fit the Norge, and have cured my pulsing front brake problem.
Alan.

Fantastic !

[blackcat]

I'm happy to report that the callipers I bought, from a 2005 Ducati DS1000 Multistrada do indeed fit the Norge, and have cured my pulsing front brake problem.
Alan.

Alan, where did you purchase the discs?

[moto]

Excellent. Did you find and mount a used Ducati caliper? From which Ducati?

[Bison]

Callipers from a 2005 Ducati DS1000 Multi strada bolted straight on.
Alan.

[Bison]

Hi,
I got them on Ebay, I assume they are chinese?. The early two valve per cylinder Norge has the abs ring attached to the disc, these ones are for the later 4V per cylinder bike, which are the same, but no provision to attach the abs ring. Luckily many Italian bikes have the same abs ring as the 4v which bolts to the wheel using the existing disc attachment bolts. I bought one for an Aprilia Shiver new from Germany, much cheaper than buying one for a 4v Norge, and exactly the same thing.
Alan.

[Pescatore]

Thanks, Bison. Great info.
I have a similar pulsing, but haven't yet ruled out the other possible causes. I'll keep this one in mind.

[Bison]

I should add, I believe a contributory factor is the fit of the anti rattle plates on the calliper which to an extent hold the pads in place. I noticed on the replacement callipers that the steel plates held the pads hard up against the calliper so that when the brake was applied there was no movement of the pads in rotational direction because they were already held in contact with the aluminium of the calliper body. My old callipers couldn't hold the pads in this place because the plates, no matter how you bent them, were incapable of keeping the pads in contact with the body of the calliper, mainly because of the wear I previously mentioned. So it's worthwhile checking the steel backing of your pads to make sure they are in held contact with the calliper body, by the anti rattle plates,  BEFORE the brakes are applied.
I hope this is explained properly, if not let me know and I'll try again.
Alan.

[Pescatore]

Pressing the 'Thank You' icon.