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09 Cal Vintage pulsating brakes!

T

Tony/CT

Just got it firing!
Joined
Jun 17, 2014
Messages
2
Location
Waterbury
Hey everyone. New to the forum...however not new to Moto Guzzi. I recently purchased an 09 Vintage with 20,000 miles on it and the first thing I noticed when braking was the pulsing of the brakes, like riding a bucking horse. My 02 Cali Special Sport did not do this and my 02 EV does not do this with twice the mileage. It appears to be the front brakes. Happens with just the front brake applied and happens with just the foot brake applied. I don't know what to replace these rotors with... if they need replacing. I've cleaned out the bobbins with brake cleaner until they turn... not the solution. Are these semi-floating rotors, full floating? The bobbins on my EV do not turn but are fixed. If I have to replace them, what is my best option without spending tons of money. I want good reliable brakes. Most of my riding is sport touring. I don't need the absolutely best brake available.I need a good replacement rotor. A problem like this could not be caused by the brake pads, could it?
 
Hi Tony, the rotors are semi-float, and a known issue on most of the Brembo round holes, and later 9-spoke and snowflakes when ordered by Guzzi. Brembo told me years ago that they are not happy with the spec's required by Guzzi, but I guess business is business. Replacement to the Brembo spec rotors are all you need, and I can get them fairly cheap ($149/side) on the Store tab above or direct here; https://www.guzzitech.com/store/category/brakes/rotors/ - happy to be of help. Contact me direct email with any questions; Todd at GuzziTech.com
 
Thanks for the info Todd. I would like to order new rotors. Would you consider the 320 snowflake rotors you mentioned above an upgrade or comparable to the standard rotors on the Vintage which have failed with only 20,000 miles on the bike? I am satisfied with the way my 02 EV stops and would be happy duplicating that bike's breaking, however, I would like rotors that will not fail again within 20,000 miles. Will the snowflake rotors accomplish this? Tony
 
Hi Tony, yes I would, as the OEM rotor is built to a price point, and the Brembo spec rotors are the same ones used on Ducati Sportbikes for well over a decade. Contact me direct email please; Todd at GuzziTech.com
 
Tony/CT said:
Hey everyone. New to the forum...however not new to Moto Guzzi. I recently purchased an 09 Vintage with 20,000 miles on it and the first thing I noticed when braking was the pulsing of the brakes, like riding a bucking horse. My 02 Cali Special Sport did not do this and my 02 EV does not do this with twice the mileage. It appears to be the front brakes. Happens with just the front brake applied and happens with just the foot brake applied. I don't know what to replace these rotors with... if they need replacing. I've cleaned out the bobbins with brake cleaner until they turn... not the solution. Are these semi-floating rotors, full floating? The bobbins on my EV do not turn but are fixed. If I have to replace them, what is my best option without spending tons of money. I want good reliable brakes. Most of my riding is sport touring. I don't need the absolutely best brake available.I need a good replacement rotor. A problem like this could not be caused by the brake pads, could it?
Click to expand...
Tony, my 07 build Cali Classic exhibited the pulsing brake problem after only 10,000ks. It was worse at low speed and using the rear/front pedal but the front right did it as well if less pronounced. My first job was to get the brake pads checked. Wearing ok. Next I ditched all 3 horrible gold centred Sunstar rotors for localy produced Metalgear front discs and a Brembo rear disc, Metalgear were out of stock for rear discs so I was forced to use an odd man out as I wanted to start from scratch. I used the original pads that came with the bike as they were not half used. The problem seemed to go away only to return with a vengeance by 20,000ks. Like before there was awful low speed pulsing and high speed brake shudder. I put the bike in for its 30,000k service just recently and it was suggested to me that Guzzis fitted with progressive calipers, i.e. One small piston with one large piston all present this problem to a lesser or greater degree? Apparently Ducatis exhibit the same problem, or so I am told? So getting really frustrated I tried original Brembo pads that have two separate pads with a drain slot that runs all the way to the base plate. Yes, you guessed it, the problem disappeared for roughly 1,000 ks only to return just as bad as ever but worse in stop start city riding. There is still high speed shudder but not as bad as before. I'm over it to be honest. So far I've spent $1,000 on discs and pads yet have gotten nowhere with this problem. It pisses me off that such a great bike that handles so well is let down by crap brakes. I drive buses for a living and can guarantee that no bus would be on the road for long with brakes like my Cali's. I Don't believe the story about the odd sized Pistons causing the problem. I think it's more to do with the thin flimsy design of the rotors. I had a 79 model SP1000 that never ever gave any braking dramas. I read one of the replies to this thread that fitting snowflake Brembo rotors fixes the problem? Sorry I'm no real help, just sharing the pain. I could also talk of my ECU and fuel pump problems??
 
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Marc, piston size has nothing to do with it. Pulsing brakes are due to either pad residual build up on the disks and/or brake dust crusted buttons that allow the rotors to "float." I'd say those who upgraded to at least the snowflakes I offer, never had a problem since. Try cleaning the rotor buttons as described in a search in the Breva/Norge section I believe.
What ECU and fuel pump problems are you having?
 
GT-Rx® said:
Marc, piston size has nothing to do with it. Pulsing brakes are due to either pad residual build up on the disks and/or brake dust crusted buttons that allow the rotors to "float." I'd say those who upgraded to at least the snowflakes I offer, never had a problem since. Try cleaning the rotor buttons as described in a search in the Breva/Norge section I believe.
What ECU and fuel pump problems are you having?
Click to expand...

G'day, Todd, thanks for the reply. I'll check the pads and the rotor buttons in due course but I'd be surprised if the buttons are siezed or the discs have pad build up. My bike is a weekend rider and everything is kept whisper clean. I'd be more inclined to change the rotors again for the ones you suggest? The link you provided seems dead so if I can obtain a set through you I'm happy to do so. Honestly, the brief periods when the brakes have been 100% they're brilliant with tons of progressive feedback in wet or dry. A mate has a 2008 1200 Griso with similar rotors to the ones your suggesting and has never had this problem.
As for the ECU. Virtually from new the bike would often run like crap. Running over lean, popping on the over ride and at times misfiring, running on one cylinder and stalling when hot. On one occasion the bike began running so rich I ran out of fuel at 150ks !! I took the bike to my mechanic who hooked the ecu into the factory program and discovered the ECU was set on completely wrong part of the map or program?? So he set it to standard, reset the air bleeds and throttle and it seemed to run ok after that. Roughly six months later the same problem reared and the bike became virtually unridable and I just managed to get the bike back to the mechanic who informed me the ECU ( WM15M ) was dead and would no longer communicate with his computer. As I couldn't afford the $1500 for a factory replacement I took the option of fitting a localy produced ECU built by Cliff Jefferies called MyECU for substantially lower cost with the ability to self adjust the map via an Android device with an app. The bike runs pretty good now but needs fine tuning. Frankly the App Cliff has produced is not easy to use for a tech dummy like my self so I'm reluctant to fiddle with it. I'd love to find a ECU specialist in Australia that could do this for me? Very frustrating.
The Fuel pump became a total failure not long after Cliff's ECU was installed. On two occasions the fuel delivery line, engine side of filter simply blew off, once before the new ECU was fitted, then again not long after the new ECU! In the end it turned out to be a failed pressure regulator. I was told this could not be repaired so I was forced at huge expense to fit a new pump. I have this theory that the pump may have been at the root of my ECU dramas all along? I'm wondering if incorrect fuel pressure may have caused the factory ECU to do some funny things? Anyway, apart from the brakes and wanting to get the ECU fine tuned there's been no more dramas. I've had more problems with this bike than any bike I've owned in 37 years of riding. Cheers, Marc.
 
GT-Rx® said:
Link fixed above and I'll post it again here; https://www.guzzitech.com/store/category/brakes/rotors/
Cleanliness isn't a gauge of pad build up or rotor button issues. Just riding it would do this.

I can't be of much help with the MyECU, but I can supply you with a good ECU for US$500 outright if ever needed; https://www.guzzitech.com/store/product/gt-rx-15mrc-re-flash/

The in-tank pumps will be a major thorn for decades to come unfortunately.
Click to expand...
Todd, when you say the in tank pumps will always be a problem do you mean for all bikes or just Guzzis? I have mates with big Jap bikes that have never had these dramas. Very odd. The ECU you offer, is it OEM?
 
Going back to the pulsing brakes one of my other bikes is a Suzuki GSX1400 and they are notorious for having this problem and it's nearly always down to warped discs. Not saying that the same thing is happening here but it's a fairly easy thing to check for as all you need to is attach a pointer of some kind to the fork legs or swingarm and spin the wheel, you'll soon see if the disc is warped, unfortunately though they can't be straightened so if they are warped they need replacing. If you have access to engineering equipment using a dial gauge on the disc will show you exactly how much runout there is.
One thing I have discovered is that brake discs can be warped simply by braking hard all the way to a standstill and then sitting there holding the brakes on, apparently the section of disc the pads are still in contact with then stay hot as the rest of the disc cools and this seems to lead to the warping. One way to avoid this is if you're out having a "spirited" ride with lots of heavy braking just ease up for the last little bit and then when you do have to stop release the brakes straight away.
 
Dave, interesting comment re your GSX 1400. I visited my mechanic who is in the process of fitting my Cali with Brembo 5.5mm front discs. It was revealed to me that quite a few makes fitted with discs as thin as 3.5mm!!!! are having the warping problems which results in pulsing/shuddering brakes. Did you measure the rotor thickness on yours? Mine were 4mm and are both warped. My braking is rarely harsh and in my opinion holding the brake in what ever position you stop should not make any difference to your rotors. If manufacturers can't fit rotors that don't warp they're irresponsible. My mechanic told me that many manufacturers are obsessed with fitting light gear to bikes now which unfortunately can result in these problems. I've gone for the thickest rotors I can fit. I had a 30 year old BMW R80/7 with 6mm front discs that never gave any problems. Might be a moral in that!
 
essexboydave said:
Going back to the pulsing brakes one of my other bikes is a Suzuki GSX1400 and they are notorious for having this problem and it's nearly always down to warped discs. Not saying that the same thing is happening here but it's a fairly easy thing to check for as all you need to is attach a pointer of some kind to the fork legs or swingarm and spin the wheel, you'll soon see if the disc is warped, unfortunately though they can't be straightened so if they are warped they need replacing. If you have access to engineering equipment using a dial gauge on the disc will show you exactly how much runout there is.
One thing I have discovered is that brake discs can be warped simply by braking hard all the way to a standstill and then sitting there holding the brakes on, apparently the section of disc the pads are still in contact with then stay hot as the rest of the disc cools and this seems to lead to the warping. One way to avoid this is if you're out having a "spirited" ride with lots of heavy braking just ease up for the last little bit and then when you do have to stop release the brakes straight away.
Click to expand...
The phenomenon you describe when braking hard to a stop and continuing to hold the brakes on typically does not warp the discs but rather leads to some of the pad material fusing to the disc in that spot. That leads to the disc being slightly thicker in that spot and that leads to pulsing brakes. True warped discs on a motorcycle are rare. It is possible to warp them, but with floating discs it is pretty hard. There are other things, like the aforementioned pad deposits and rotor buttons that stick and do not allow the disc to properly float.
Upgrading your discs to higher quality discs like the Brembos Todd offers can be a serious improvement. I really like the T Drive discs. But any disc can suffer from uneven pad deposits or stuck rotor buttons. Proper care and maintenance of your brakes goes a long way. Also, pad choice plays a large part. The pads and disc should be thought of as a pair.
 
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I have owned many a disk brake motorcycle. In my younger days I upgraded an old single disk CB650 Honda with dual disk CBX brakes. I used them hard enough to turn the rotors blue, (stoppies). No problems. I have owned 2 Moto Guzzis. My 2007 Norge warped the rotors and my 2014 California Tour is pulsating and the dealer is trying to get me new rotors now. I have worn the rotors with grooves on a PC800 but no warp. Only on my Guzzis.

If Guzzi doesn't warranty it I'll have to send Todd money and I know he hates that.
 
If you're successful in getting Guzzi to warranty your discs they'll only supply what's on your bike now which is at the root of the problem. The 4mm thick discs and the alloy centres are too light for the bikes they're fitting them to. They feel ok when they're cold but as soon as they warm up they warp which causes the awful pulsing. Keeping the pads, discs and buttons clear is only part of the problem. I've now covered 300 ks with a new set of Brembo HD5.5s on my Cali and they're excellent. I'm not sure how thick the discs are on the Cali 1400 but if they're under 5mm and the carriers are too light you'll get the same dramas. As I mentioned before in an earlier post, my trusty old BMW R80/7 covered close to 180,000 miles and not once did I have dramas with the front discs, they were roughly 5 or 6mm and had heavy carriers.
 
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