Breva/Griso info

[Guest ratchethack]

I what does "frontbottom " mean?

frontbottom - the design location of the V11 and other Guzzi rear brakes. The "front, bottom" location of the caliper ensures that the caliper will load up prematurely with a combination of brake dust and flotsam and jetsam from the road, caking-up in spectacular fashion into a near-solid mass between the brake pistons and calipers. Garden-variety neglect of regular cleaning of the caliper and the usual lack of regular changing and bleeding of brake fluid will act together, resulting in the hanging-up and dragging of brake pads on rotors and expansion of air and water vapor (from water in the fluid) due to heat build-up in the caliper. This causes dramatic premature brake pad wear, overheating of disks, and eventual brake lock, with potentially catastrophic results on the road. Early warning symptoms - backup "groan" or "squeal". See many posts on the phenomenon.

 

What is the relevance of ZING????

zing - What Terry "Astro" Wilson (Астро или Терри Вильсон) enjoyed so much that he put into song. Massive quantities of zing evidently compelled him to do his own t'ing. See below.

[badmotogoozer]

Sorry, I'm still lost on this zinging thing???? Please explain so I can either laugh or get indignant and start putting the stick about

 

Pete

78518[/snapback]

 

You're going to want to start "puttin the stick about" Pete. There hasn't been a insult like that on this forum in a loooong time....

 

Rj

[pete roper]

You're going to want to start "puttin the stick about"  Pete.  There hasn't been a insult like that on this forum in a loooong time....

 

Rj

78620[/snapback]

 

Like I give a f@ck?

 

OK, for anyone who has stuck with the original topic? Yes, you at the back picking your nose! You! Listen and learn.

 

I was wrong about the bearing's function. It seems that within the CARC system the crownwheel is shimmed with tapered roller bearings in a *Bridge*.

 

The actual bearing that goes tits is what stands in for a wheel bearing on an *ordinary* wheel.

 

OK, Pay attention.

 

The Guzzi part # is 92208518.

 

It is a ball race with dimensions of 85 x 120 x 18 and the problem with the cannibal bearings is that the cage is poorly riveted, it stretches and falls to bits digging out the seal as it does so and puting oil on the rear wheel. Unlike my earlier supposition though it WON'T have any effect on then rownwheel and pinion mesh, this is good news.

 

The ISO standard for the bearing is #61917. They come in three types. The steel caged one, one with a polamide cage, (Not good, visit Guzzi Exchange for details.) and a brass caged item. Brass caged item has higher load rating but lower speed rating. Noting that by a very rough calculation the rear wheel is revolving at 5,760RPM, (At 200KPH.) and the steel caged bearing is rated to 6,000RPM I'd stick with a real steel cage bearing made by sombody who doesn't have a bone through their nose.

 

Over here a *real* bearing from SKF or whatever and made in Europe, Japan or the USA will cost about $165, that's to me at trade, I dunno retail.

 

The main reason that I'm passing this on is that after I;d done the research and talked to the local importer I went to my local *Official* dealer to offer him this advice. When asked if he's like a precis he said "No" because thare had been no recall and no service bulletin notifying him of the problem therefore it was all bollocks and I was talking out of my arse. That's fine, I gave him the info in written form anyway so when he does get angry customers on his doorstep at least he *should* have the information if he diddn't simply screw it up and stick it in the bin the moment I was out the door

 

This is NOT a universal problem, but it is usefull to know that there have been at least 10 cases in Oz. Be aware, it's an easy fix for dealers who care.

 

No seals were clubbed in the delivery of this message!

 

Pete

[callison]

Moto Guzzi spent 50,000 hours testing the new engine. One wonders just how many hours were spent testing the new CARC suspension. 10,000? 5000? 250? Lunch hour and a trip to Luigi's?

[pete roper]

Moto Guzzi spent 50,000 hours testing the new engine. One wonders just how many hours were spent testing the new CARC suspension. 10,000? 5000? 250? Lunch hour and a trip to Luigi's?

79017[/snapback]

 

 

Carl, to quote the tech lad at the importer, "Everything in there is typical Moto Guzzi. It's built like a brick sh!thouse and everything is five times larger than it actually needs to be!"

 

Once again I don't think it was the designers who have let the side down, it's the fact that someone in parts sourcing and pricing found some fantastic, cheap, #61917 bearings, (Probbably a water-damaged consignment that had been delivered from Bongo-Bongo Land as deck cargo on a submarine!) on fleabay and snapped 'em up. The fantastic cost saving of $10 per machine made it all worthwhile, NOT! Now they have to deal with all the stupidness that comes as a result, I hope they find whoever was responsible for the purchase and stick his balls in a vice.

 

Why Guzzi continually, decade after decade, make the same mistake I don't know? Perhaps it's the same bloke in parts sourcing who's been responsible for all the problems since 1984? If so it's time he was pensioned off with a pair of concrete boots and dropped off the ferry to Lecco mid lake!

 

Pete

[Guest Nogbad]

I would be interested to see an exploded diagram of the CARC driveline. Sounds like an odd size choice if the only load is one side of the wheel. A big MF like that can probably stand a radial load of about 3 tonnes, but as you point out, its getting iffy on speed rating, although I don't suppose many Grisos and Brevas will do 200kph for many hours.

[pete roper]

I've seen an exploded diagram of it but it was a couple of months ago so it's all a bit hazy, hence my confusion about the bearing purpose.

 

If someone could post up a pic of the drive it would be helpful but essentially the wheel is *dished* if you like and I imagine that the bearing itself, which acts like a wheel bearing, (the wheel itself, mounting to the CARC on studs as a car wheel does to the axle hub) runs in the centreline of the wheel, or bloody close to it.

 

From memory the actual crownwheel and pinion assembley sort of *floats* inside the main case with the crownwheel supported in a bridge assembley on tapered rollers. This in turn fits into the *wheel bearing* on one end and, I suppose, another bearing on the other. The bridge assembley can therefore move within the main case and the pinion carrier end and the box on the whole are sealed at the front by a rubber boot.

 

I too am eager to get a better look at one. The only one I've seen was one of the ones that had dropped this bearing and that was only a fairly brief glance at the importer's workshop in Sydney when I went up to test ride the Breva. Chances are when I get my Griso I'll be pulling the arse end of it out to check it and maybe replace the bearing anyway with something trustworthy but if I do I'll probably do a photo series on it and post it up, most likely on Wildguzzi 'cos posting stuff up there is easy and I know how, and then Jens will probably lift it, turn it into PDF's and post it up on Guzzitech dk.

 

Oh yes, on the speed rating thing I don't think it's an issue. Even if you accept that my rubbery figures are close to correct in terms of speed in RPM at the given road speed the fact is that as you say if the bearing is rated to 6,000rpm constant then you'd be unlikely to broach it's safety envelope. While I expect a Griso or Breva will probably pull 200KPH down a well greased mineshaft with a following gale the fact is that I think it highly unlikely that many, if any of them, will spend much time at that sort of speed. Apart from anything else the idea of trying to hold on at that sort of speed for any length of time makes my eyes water! My guess is that once the tuner boys start warming over the engine what will be being chased is midrange stomp rather than outright top end. On most Guzzis the limiting factor on a *hot* motored bike is the gearing rather than power. If riso owners run out of gears before the rev limiter cuts in the best option would be go to a set of Breva primaries.

 

Pete

[dlaing]

Regarding "zing"

I define it as a combination of definitions one and two, which basically combine, to define definition three (all of the word zinger, with zing the expletive form of the word zinger)

 

   

1* unusual and generally humorous feature story often placed at the end of a newscast

      www.newscript.com/glossary.html

 

2  * Slang for the pain inflicted by any movement of the body when performing, or viewing a competition in sub-zero weather.

      babpo.wso.net/glossary.htm

 

  3  * a striking or amusing or caustic remark; "he always greeted me with a new zinger"; "she tried to think of some killer of an argument, a real zinger that would disarm all opposition"

      wordnet.princeton.edu/perl/webwn

 

[todd haven]

Here ya' go, Pete

 

 

[pete roper]

Here ya' go, Pete

 

 

79361[/snapback]

 

 

OK, to the bast of my knowledge it is part #4 that is going tit's up and pushing it's cage through part #10, the seal. As is shown in the pic none of the *Important* bits are available apart from as an *assembley*. I don'tdoubt that they will be in the future but the good news is that the bearing is reasonably eay to get at.

s

Pete

[V11UK]

Pete - at what mileage have the few failures occurred? My Breva has done 5,300 miles and the back wheel/CARC drive unit seems fine. BTW the bike is a '1st Series' model bought in August 2005.

[pete roper]

As I've tried to say so that people don't panic it isn't a universal problem. It would seem that there was a bad, (read cheap and nasty.) bearings bought by some cretin in goods recievable and some of them are obviously made of compressed buffalo spoof.

 

As far as I can ascertain if they are going to go tits up it seems to occur fairly early in the piece. The two I *know* the history of are the press demo Breva and Griso, both of which shagged the bearing cage while being thrashed by journos. Since they usually get given nearly new machines I'd think that these two failures would of occured within the first 5,000Km.

 

The thing to look out for is spotting or streaking of oil on the rear wheel and/or tyre. As the bearing cage breaks up it pushed bits of itself through the oil seal so a leak develops. The odd thing is that once the seal is munted it doesn't neccesarily throw out huge volumes of oil which I would expect it to do which makes me wonder if the bearing gets sufficient lubrication as everything in the bevelbox is fed by splash

 

Post Dec )5 bikes are supposed to be fitted with a superior bearing. While I wouldn't worry unduly I think that if i had an earlier bike I'd change the bearing out just to be on the safe side but I doubt you'd get that done under warranty unless they do have a recall.

 

Pete

[V11UK]

Thanks for a thorough explanation Pete. I've been following this topic since noticing your first post on Todd's MG-Griso forum but haven't been unduly worried by it. Considering my Breva's done 8,500 km without any problems, I reckon it's pretty much OK.

 

It did occur to me that having the bearing changed to SKF (or similar) for peace of mind would be worthwhile - even if it means paying for it myself and not under warranty. I'd hate to have a problem miles from home .

[bigbikerrick]

Thanks for a thorough explanation Pete. I've been following this topic since noticing your first post on Todd's MG-Griso forum but haven't been unduly worried by it. Considering my Breva's done 8,500 km without any problems, I reckon it's pretty much OK.

 

It did occur to me that having the bearing changed to SKF (or similar) for peace of mind would be worthwhile - even if it means paying for it myself and not under warranty. I'd hate to have a problem miles from home  .

79504[/snapback]

another thing to think of is if you change it to an skf yourself, and then it goes to shit due to poor design/insufficient splash lubrication, or whatever, and the rear drive sustains collateral damage, MG may not warranty it. I say let sleeping dogs lie,and if it aint broke, dont fix it!

[leafman60]

This topic amuzes me. I also ride BMW's and they have experienced an epidemic in recent years with a similar problem on their rear drives. We have a local group of about 12 BMW riders and 4 of us have had rear drive problems on late model BMW's. The big K1200LT series and the R1150GS seem to be most prone to this problem. My 1150 GS falied at about 20lk miles. Even the latest R1200GS with a redesigned rear drive is having this happen. The big ring gear bearing disintegrates and the cage cuts the seal up and all the oil rains out. Sounds just like the reported Guzzi flaw. The embarrasing thing is that Ive gotten a lot of the guys looking at Guzzi as an alternate to the BMW. Now they'll balk, as will I. I may tweak a lot of folks but the slickest and most relaible rear drive that I currently have is the belt drive on the Harley. Ive also not had one single issue with the Hog except that you see too many of them on the road.