Rear brake help

[Lex]

I did a quick search and didn't find anything on this. So I am hopping one of you can help me.

 

Background: I had the problem several others have had with my rear brake on my 2001 V11 Sport over-heating when the bike was new. This is in spite of the fact that I very seldom use the rear brake. I installed a spring to push the brake pedal down so I could have some movement between the normal position and the application of the rear brake. I figured the problem was my foot brushing the pedal as I rode. I haven't had a problem since.

 

Problem: Recently I changed my rear tire. I checked the thing you would normally check and found the rear pads to be worn-out. I got a new set of pads today and got ready to install them. The first thing that bothered me was the inside pad was only half worn, the outside pad was worn out. OK, that is not good but given the problem I've had maybe the outside pad was over heated or something. So I started to install the new pads. A nice, easy job, knock out the pin, pull the old pads, put the new pads and the little spring that goes under the pin and put the caliper back. Everything went well until I tried to put the caliper back in place. With the pistons fully retracted the inside pad has plenty of room, maybe 1/16" (1.5MM) of play. The outside pad is so tight it is very difficult to install the caliper and once you do the outside pad drags on the disk. The disk fits between the pads just fine, put the caliper in position and tighten the bolts and the outside pad drags. I can only conclude the caliper is offset toward the center of the bike.

 

Question: Why is the caliper offset toward the center of the bike? I believe I have the wheel mounted correctly. From the drive side the order is swingarm, thick washer, final drive, spacer, rear wheel, rear brake mount, swingarm, washer, axle nut. Am I missing a spacer? The manual is useless as it doesn't even shop some of the parts that are there. It seems like a thin spacer would move the caliper over just enough to make things work. If I'm not missing a spacer is this another Moto Guzzi screw-up?

 

Ideas Please!

 

Lex

[twhitaker]

Sounds strange. I've had heat and groaning problems with my rear brake. Using the disc brake cleaner is a good temporary fix for both. I've not had to replace the pads so I have no definitive answer. Spacer washers between the caliper and the mounting bracket may be in order and not unheard of. My Convert, which had fixed rotors, had these washers.

[Lex]

twhitaker,

 

Thanks for the try.

 

I resorted to my crude self and made a shim out of 0.032" (0.81 MM) aluminum stock. I put the shim between the wheel and the caliper mount and the problem is gone. The caliper drops in place like it was intended to.

 

I'm thinking I am a victim of Moto Guzzi (total lack of) QC. Will the next person who makes it the factory please bitch slap the first quality inspector you find for me? This is kind of funny story now, how funny would it be if the wheel had locked up in mid corner? I hate hospitals.

 

Lex

[twhitaker]

Have you had any problems with your wheel bearings? Some bearing problems have been attributed to the inner spacer being 1mm (.039") too short. Could that be where your offset lies?

[Lex]

Have you had any problems with your wheel bearings? Some bearing problems have been attributed to the inner spacer being 1mm (.039") too short. Could that be where your offset lies?

37194[/snapback]

 

twhitaker,

 

Yes to the problems but I do not think this is related. I think (only think) my bearing failure was caused by the bearing getting very hot (the paint on the disc carrier is burned!) and the limited grease supplies by the factory making an exit. The bearings were knackered at about 3700 miles, I have 5600 miles on the replacements with no problems.

 

This is just my theory, the root problem could be the width of the wheel/ wheel bearings. I'm keeping a close eye on the wheel bearings, if they last I think my spacer is OK. If they fail again I'll look into the length of the spacer.

 

Lex

[Baldini]

Lex,

 

All parts are as listed in parts book. Does first (drive side) washer fit flush w/drive box?

 

Is the spacer an interference fit between the bearings?

 

Does the centreline of the caliper centre on disc edge before/after you shimmed it?

 

If problem recurs, you could measure bits & post for comparisons.

 

KB

[Lex]

Lex,

 

All parts are as listed in parts book. Does first (drive side) washer fit flush w/drive box?

 

Is the spacer an interference fit between the bearings?

 

Does the centreline of the caliper centre on disc edge before/after you shimmed it?

 

If problem recurs, you could measure bits & post for comparisons.

 

KB

37810[/snapback]

 

Baldini,

 

The bike is at Monroe Motors in San Francisco as I write this. They did the transmission recall and checked out the brake problem and a few other things. When you live 250 miles (about 400 kilometers) one way from your dealer you save up a list of problems before you visit.

 

Anyway, they said all the correct parts are there and they are in the correct order. They resorted the fast way to troubleshoot the problem, swapping parts. It looks like the problem is the caliper mount being made incorrectly. They came up with a better shim in the short run (steel and no doubt better made than my homemade junk) and have filed a claim with Moto Guzzi to replace the caliper mount. My factory warranty expires next week (I have four more years on the extended warranty) so it was good timing.

 

I'm going up to the city to get the bike tomorrow, I'm really looking forward to having it back. Riding the BMW is OK. Actually the fat bike has been kinda' nice since it has been cold (Near freezing at night! How is a wimpy Californian to survive? ) and the heated seat and grips have been on and the wind blocking of the fairing appreciated. But the Goose is just more fun. I keep thinking about a 2005/ 2006 Moto Guzzi with a small windshield and a grown up sized alternator. I think I need a summer Goose and a winter Goose.

 

Lex

[Baldini]

.....I need a summer Goose and a winter Goose..../quote]

 

Yeah, trouble is they all end up been summer ones after a while & you always need another winter one...

So have we got another item to watch out for tolerances now! Wonder if that was problem on other bikes which had binding/overheating on rear caliper/disc...

 

KB

[Crooz]

I just bought an 2002 with 4200 miles and my rear brake is not flowing freely, thus makes the graoning noise and getting sort of hot.

So all I need to do to correct this is shim the caliper & the mount ?

[belfastguzzi]

I just bought an 2002 with 4200 miles and my rear brake is not flowing freely, thus makes the graoning noise and getting sort of hot.

So all I need to do to correct this is shim the caliper & the mount ?

First: have you cleaned it – made sure that the pistons move freely?

[Crooz]

First: have you cleaned it – made sure that the pistons move freely?

 

I have not removed nor cleaned anything yet. Heck it's only has 4300 miles on it.

I do plan on investigating further and tinkering with it in the coming days.