Linked brakes

I wish to replace the old brake hoses on my V50 II with braided hoses.
My concern is to whether or not there is any form of pressure restrictor in the line to the front left caliper or does it receive full foot pressure ?
I have removed the lines to inspect and there is nothing at the master cylinder or in the rigid line up to the point where it joins with the flexible hose but I can’t be sure if there isn’t something at that joint.
Any comments please ?

There won`t be any restrictions in the pipework as its the master cylinder that regulates front and rear pressure


I’d say so, but on the other hand, as my way of regular overhaul of brake calipers looks like: halve them, pull pistons out-clean-fill up with DOT-pistons in-halves back together - and THEN, push pistons in to press all the air out in one simple shot - I have experienced unexpected problem once, when fluid just didn’t want to flow back to master cylinder, no matter the force applied to piston. Can’t remember which caliper was that, front or rear, but it was surprise for me, and I didn’t solve it. I had to remove air classic way. So - possibly there is something on way from master cylinder, as if not, how simple splitter would make unequal action, sending more force forward, less back?

The splitter units on most Guzzis is just a manifold with a feed in from the master cylinder and 2 outlets one front one rear. Only a few have any sort of proportioning inside, such as the early Spada, some Cali 3’s and I expect others.
If you are having problems pushing fluid back from the caliper to the master cylinder, there are a few possible causes.

  1. Blocked pipes that have degraded with time (rare)
  2. The larger of the 2 small holes in the bottom of the master cylinder reservoir has become blocked with crud (fairly common)
  3. The master cylinder piston is slightly depressed. This closes off the hole from the reservoir into the pipework and stops fluid flowing back up the system. I had this on my Cali when I overhauled the brakes. I tried the reverse bleed technique everyone talks about and it just refused to work, I tried vacuum bleeding the system, that would suck but the air got just pulled back into the system. I took the master cylinder off and tried blowing up the pipe, all fine, put it back on and did the same and it was blocked. Turned out the pedal adjustor was just touching the piston.

As the rubber hoses are only fit for the bin anyway I removed the one that joins the rigid pipe from the master cylinder to the front left caliper and cut the rubber away from the union so that I could inspect inside and there is no sign of a restrictor there.
I have also removed the Y piece from the back of the master cylinder and there is no restrictor there.
As the Y piece receives the full output pressure from the master cylinder piston and there are no restrictors that I am aware of then the rear and front calipers must receive the same pressure, ie there is no proportioning.
An interesting state of affairs and I would be curious to know if anyone has ever experienced a “moment” from the front end, particularly in the wet, if the rear brake pedal is used in anger.

That’s the thing, I rode V50 as a commuter for couple of years, winter/summer no break, and I have never - never! - experienced any bad behaviour of the front wheel, while linked brake was effectively the only one, front one being just a bad joke:)

What he said -

An interesting state of affairs and I would be curious to know if anyone has ever experienced a “moment” from the front end, particularly in the wet, if the rear brake pedal is used in anger.

That’s precisely why the linked system was invented, safer to use in the wet. So, no! :smiley:

Several times I’ve been glad to have it, where hitting the front lever (either instead of, or as well as) seemed more dodgy.

There is certainly no pressure proportioning valve in the linked braking system on my V50 II. My understanding is that the proportioning is done by (a) different diameter discs (larger on the front) and (b) different pad compounds on front and back. Presumably the front has a higher friction coefficient than the back. Strangely, the non linked front caliper uses the same pads as the rear, which might be another reason why it has such a poor reputation.
EBC offer sintered (HH) and kevlar brake pads for the V50, and on MSA’s website it says ‘To avoid brake imbalance DO NOT use Double-H pads on the rear UNLESS also fitted to the front’
However, presumably it would be better to fit Sintered to the front and lower friction kevlar to the rear to maintain brake balance.

Only time I’ve managed to confuse it was when tramping on hard with a sidecar. Ordinarily the linked system just sucks the bike down on to the tarmac at both ends, calmly and efficiently.