radial master cylinder for two P08s?

[lazlokovacs]

paging rodekyll or anyone else in the know...

LM2 de-linked, I have a spare PS16 that I thought would do the job, but the travel is too long until it bites and I've been spoiled by radials on other bikes.

So... what's the go-to radial M/C for the lemans?  de-linked two old school P08s

 

[wirespokes]

I'm curious if there's any difference between a master for a radial and one for the 'normal' calipers? You know, I really can't see how they could be any different - they each need to pump fluid... right? I'm guessing it's all in the master's bore size.

But maybe I'm totally in the dark here since I don't have any bikes with radial brakes, and they're radically different?

[guzzisteve]

If you do a search here, there is a chart for the size, been on here more than once.

[Dukedesmo]

I've got a Brembo RCS 15 on my de-linked LM2 and it works perfectly.


Whilst not up to the 2-finger braking of my other (radial braked) bikes, for a 40+ year old bike the brakes are remarkably good. I did, however completely overhaul the calipers with new pistons/seals/pads and braided lines to get the absolute best from them.

[lazlokovacs]

If you do a search here, there is a chart for the size, been on here more than once.

thanks steve, I did do that search before I posted, and read the relevant stuff in guzziology, there's no chart for radial master cylinders that I can see on this site.

Sizing radial mcs still remains something of a dark art

[lazlokovacs]

I've got a Brembo RCS 15 on my de-linked LM2 and it works perfectly.

boom that's what I wanted to know!

 

[Dukedesmo]

Fits nicely too, as you can see in this pic without the fairing;





Nice, progressive action and doesn't 'bottom out' against the twistgrip. It's never going to lift the rear wheel but that's probably more to do with the weight & length of the bike than brake power? but it can certainly stop quickly enough.

[Roebling3]

As new there was no way to trust the brakes ohttps://wildguzzi.com/forum/Smileys/default/lipsrsealed.gifn my 2017 'racer'. The brakes could not be bled reliably. Not my way, the factory way, or by a guy as skilled as Jim Hamlin w/factory program. Rather than dying while trying Jim offered a 4 pot Brembo w/fully adjustable, radial MC +/remote rez.  2 weeks later the bastard cured itself.

That front brake is wonderful, in every way..
I'd like to rid myself of the useless abs weight.  R3~

[rocker59]

I'm curious if there's any difference between a master for a radial and one for the 'normal' calipers? You know, I really can't see how they could be any different - they each need to pump fluid... right? I'm guessing it's all in the master's bore size.

But maybe I'm totally in the dark here since I don't have any bikes with radial brakes, and they're radically different?

the brake fluid doesn't care.  You can have axial master cylinder controlling radial calipers, or you can have radial master cylinder controlling axial calipers.

this post is about radial master cylinders.  they're great.  I used a Brembo GP radial front master cylinder on my Sport 1100, which had the old single-pin Gold Series axial mounted calipers.

The radial master cylinders have great feel.

[wirespokes]

The radial master cylinders have great feel.

When you say it's got great feel, what do you mean? Are you saying the brakes modulate well requiring minimal strength at the lever?

If that's the case, then that's a function of the MC size. The axial masters on my bikes (all smaller bore than stock) have great feel.

From data I've gotten, the only difference between axial and radial masters is the radial requires less space on the bars. And, possibly because of the layout with the piston pumping crosswise, they seem to need to be a few mm larger than axial masters.

But it's still just a pump - so please explain how a radial master can feel better than an axial. What feels different about them?

[Dukedesmo]

My understanding of radial master cylinder advantages are primarily space which is particularly important on short clip-on bars, I think I have heard claims of increased rigidity too due to the way it pushes? but hardly think it would be noticeable in everyday riding.


But in the case of the Brembo RCS they have a dual ratio (pivot length) of 18mm to 20mm, giving you a choice of firmer or more stroke with resulting better 'feel'.

[rocker59]

it's still just a pump - so please explain how a radial master can feel better than an axial. What feels different about them?

Agreed, it's just a pump.  However, they feel different.  I've owned and ridden a lot of different motorcycles over the years.  Ridden several Ducatis with radial master cylinders.

My personal experience is on my 1996 Sport 1100, which I was riding pretty hard at the time.  I removed the OEM Brembo master cylinder and added the then current Brembo GP radial master cylinder.  It was powerful with great modulation, requiring less effort.  I rode with one or two fingers on the bike.  Only chirped the front tire one time, and that was at a track day under hard braking over some slightly rippled pavement.   

I submit that my experience is anecdotal.  But that's all I've got.

[Alfetta]

I rode with one or two fingers on the bike.
I submit that my experience is anecdotal.  But that's all I've got.

Funny thing, my only mod to my V7 was to half the length of both the clutch and brake lever. I guess I have too many years on dirt bikes, and I cant stand having to open my entire hand to grab a lever.  I have found the stock brake cylinder quite sufficient with only two finger activation, and surprisingly the clutch as well..

and this is my anecdotal experience...

[acguzzi]

the force on the pivot point is about half with a radial as the forces are essentially in the same plane, probably the reduced friction improves feel