Front brembos orientation

[Ernesto]

Is the "behind the forks" position argument the relative "anti-dive" effect produced by the braking resulting force ?

Guzzis  used to have the calipers leading then they swapped them to behind......... Probably happened around 76 with the LM I.

Hi,
the swapped calipers were introduced with the LM 2. I remember the article in the German motorcycle
magazine stating that Guzzi did this because of that "anti-dive" effect St?phane mentioned.
But never read such afterwards, if there was a significant effect, all bike builders would have equipped
their bikes with the "behind the slider" version immediately, wouldn't they?

Ernesto

 

[Davo]

Considering only the right front caliper on a Guzzi works alone and the rear caliper and front left are linked I am not sure there is much of a comparison to be had with our bikes. BTW, braking in a corner or emergency braking in a straight line with the linked front and rear brakes is brilliant. Almost considering pinching a splitter from the wreckers and fitting the same system onto the Lav.

 

[blab]

Considering only the right front caliper on a Guzzi works alone and the rear caliper and front left are linked I am not sure there is much of a comparison to be had with our bikes. BTW, braking in a corner or emergency braking in a straight line with the linked front and rear brakes is brilliant. Almost considering pinching a splitter from the wreckers and fitting the same system onto the Lav.

good way to f/u a decent bike

 

[Davo]

If you ain't tried it, don't diss it.

I hated the idea when I bought the Le Mans and was going to change it to conventional. However, one episode of emergency braking in a hairpin that I had entered way too hot and the way the bike maintained it's poise under heavy brakes on a heavy lean far better than I did convinced me to keep them. And further use in extreme conditions and then a day of advanced rider training where it outbraked most of the modern bikes, especially if they were honest and had turned off their ABS, totally sold me. The linked brakes work just great.

 

[Dellortoman]

Yeah, I've kinda got used to the linked brakes. They're on both my Benelli and Guzzi. They're a whole lot better than I was expecting before I'd tried them. I've not had to use them in a serious panic situation (I obviously don't ride as close to the limit as Davo) but using the rear linked brake feels quite balanced and stable.

 

[Tippie]

but using the rear linked brake feels quite balanced and stable"
And that is the reason they introduced it. Riders not properly trained simply "stamped on the brakes" like in a car, locking the rear and continuing into the thing they wanted to avoid. Linking a front disc to the foot pedal helped immensely.
There is no splitter, simply a junction which divides the fluid from the rear MC to go to front and back. The ratio is achieved by the size difference in the discs. There is no apportioning valve, could achieve the same on any bike, just run a double banjo from the rear MC, one hose to one front caliper.
My VFR has linked brakes, can ignore them most of the time but a bastard on gravel when I just want to use the rear. It has locked the front on me a few times.

 

[Davo]

Later Geese do indeed have an apportioning valve, I think from the LM 1000 onwards, and later still have ABS at least on the Norge.

 

[Dellortoman]

The ratio is achieved by the size difference in the discs. There is no apportioning valve

Quite right Tippie, there's nothing fancy in the hydraulics of the old bangers - just plumbing.

I just took some measurements and worked out the braking effect front and rear:

The Guzzi LM1 has 54% front bias, 46% rear.
The Benelli 900 Sei has 40% front bias, 60% rear.

The reason they're different is that the Benelli has larger caliper pistons at the back. 38mm F08 front, 48mm F09 rear. Both bikes have 260mm rear disks. Benelli front disks are smaller than the Guzzi (280mm and 300mm respectively) so the Benelli has less braking effect at the front and more at the rear. 

Can't say I've noticed the difference on the road. But I'm not in the habit of riding either bike anywhere near maximum braking effort.

Cam

 

[Simonr501]

Is the "behind the forks" position argument the relative "anti-dive" effect produced by the braking resulting force ?

S.

The augment was concerning the bike having a lesser tendency to stand up and run wide while trail braking in corners.

The two quotes above are non-compatible, one says that forks extend (anti-dive) the other hints that forks compress.

For vectors, thinking about which direction the pads would go if they were unrestrained with calipers behind, when trying to brake they would fly upwards and forwards so that must be the direction of force, compressing the forks and shortening wheelbase?

 

[Vince]

Now why would we want any of that fancy engineering talk.I have no idea what if any effect is changed,be an interesting discussion and maybe finely put it to bed.They still look better behind,I also like the load going into the leg more than into a couple of bolts.Thats just the seat of my arse builder brain liking the look of direct structure.Wouldn't amount to anything significant  except looking right to my eye.

 

[Davo]

Being a non-engineer, non-mechanic I would have thought the greatest effect on front end handling under braking would have been the shift in weight distribution of the rider and bike. Combined mass of rider and bike wanting to continue in the initial direction and speed of travel but being prevented from doing so by the front wheel which is now travelling slower. The centre of mass of the front wheel being lower than that of the rider/bike will then shift the angle of travel downwards. Wouldn't matter which side of the forks the calipers were on in a meaningful way.

 

[Harry Lime]

Is there a 'correct' orientation from a safety viewpoint rather than the rivet-counter POV ?

The only "correct" orientation would be how it left the factory.

Make sure you tell your ins. co. you've reversed the mounting of your front brakes..................?

H.