EV1100 brake correction device

[jmac851]

Can anyone explain what this "brake correction device" actually does?  I have this on my 1998 but not on my 1996.  Both are California models.

[oldbike54]

Can anyone explain what this "brake correction device" actually does?  I have this on my 1998 but not on my 1996.  Both are California models.

 Are you referring to the proportioning valve for the linked brakes ?

  Dusty

[jmac851]

I'm referring to the part that is located on the underside of the left leg of the swing arm. A brake line comes from the distribution block down to this thing and then another line goes out to the rear brake caliper.

[pehayes]

There is a spring connecting the swingarm to this 'balancing' valve.  When you add weight to the rear of the bike (luggage or passenger) the swingarm rises and changes angle.  The spring linkage interprets this change and then shifts or adds more hydraulic pressure to the rear brake disc.  Conversely, when riding solo, there is less pressure to the rear brake.  The idea is to prevent a rear wheel lock and skid.  With more weight in the rear, the bike can handle more braking pressure without lockup.

Its a subtle system.  I'm not sure just how accurate it is.  However, if you change from stock length shocks, you also have to modify the adjuster screw so that the same amount of swingarm deflection results in the same amount of pressure alteration.  See my explanation here:

http://www.guzzipower.com/IntegEVBrakes-Pat_H.html

I'm not a professional engineer.

BTW, that connector spring ($2) broke on Regina's 98EV during warranty.  They refused a free replacement as it was considered caused by abusive riding and improper braking technique.  ??????  Nice job Guzzi.

Patrick Hayes
Fremont CA

[oldbike54]

I'm referring to the part that is located on the underside of the left leg of the swing arm. A brake line comes from the distribution block down to this thing and then another line goes out to the rear brake caliper.

 What the esteemed Mr Hayes is saying is that YES , it is a front rear brake proportioning valve .

  Dusty

[sib]

All things considered, it's a crude way to prevent wheel lock-up. I prefer the ABS on my '16 Stone.  I know that many enthusiasts here like the older bikes, but sometimes progress does occur.

[Triple Jim]

BTW, that connector spring ($2) broke on Regina's 98EV during warranty.  They refused a free replacement as it was considered caused by abusive riding and improper braking technique.  ??????

I've experienced that kind of crap from other companies before.  Their lawyers tell them that replacing it free is an admission of a defective part of a safety related system, so their official line is it's a customer caused problem.  It happened to me with a broken bicycle crank, and I saw it happen to a friend when an aluminum casting on his ultralight's pontoon mount broke, causing a crash landing into the water.  Abuse by the customer, metal fatigue due to old age, etc..  They can come up with lots of reasons their parts didn't cause the problem.

[Kiwi Dave]

All things considered, it's a crude way to prevent wheel lock-up. I prefer the ABS on my '16 Stone.  I know that many enthusiasts here like the older bikes, but sometimes progress does occur.

Progress?  Then why was it dropped on the later Vintage models?  Since the foot brake also operates one of the front discs, it is too easy to lock the rear wheel when braking hard without this simple addition, especially if the rear wheel gets airborne. 

[jmac851]

My 96 1100i doesn't have one.

[rodekyll]

It was explained to me as a kind of anti-dive device.  If you use too much front brake the nose wants to go down and the tail pitch up.  When that tail pitch happens it pulls the spring and auto-applies a little rear brake to counteract the dive.  Also called an 'anti-jack' valve because it damps the rear 'jacking' effect of a driveshaft bike.

But I have no idea what the factory might have had in mind.

[LowRyter]

The EV has linked brakes, rear + left front.

[rodekyll]

Yes, mine does. 

[jmac851]

My 1984 had linked brakes without this device. My 1996 has linked brakes without this device. After many miles on both, I never had a problem with the back brake locking up.  The proportioning valve is located on the outlet for the front brake from the distribution block.  It opens and lets fluid flow to the front brake after 5-6 bar of pressure is applied.

[rodekyll]

Neither your 94 ot 96 had a lot of things that the EV did -- like the dogbone driveshaft, efi, wider swing arm, fatter tires, etc.

They did have a tendency to jack the swingarm though, and that's what the brake thingy is supposed to help with.

[PandionExpress]

BTW, that connector spring ($2) broke on Regina's 98EV during warranty.  They refused a free replacement as it was considered caused by abusive riding and improper braking technique.  ??????  Nice job Guzzi.

I know I am a few years late on this thread, but where did you find that spring for $2?  I am finding it for $20 at https://www.piaggiopartspro.com/oempartfinder.htm?aribrand=MGZ#/Moto_Guzzi/GU017_California_Special_1100_1999-2000/Front_LH//rear_brake_system/01%7C~GU017/GU017%7C~3316

Thanks

Andrew

[pehayes]

I know I am a few years late on this thread, but where did you find that spring for $2?
Andrew

That was nearly 20 years ago!  The broken spring was within a  year or two of purchase and should have been under warranty.  Probably the price back then.  I wouldn't have a record that far back.

Patrick Hayes
Fremont CA

[PandionExpress]

Ahh, well that would certainly explain the order of magnitude change in price!  Thanks for clarifying that for me.

Noticed my spring was no longer connected to the braking correction device the other day. Figured it was worth checking if i could save almost $20 bucks.

Cheers,

Andrew