Master cylinders upgrade

N

NToxx

fast rider
Joined
Nov 13, 2022
Messages
34
Location
France
Hi everyone,

While waiting for a better weather I was thinking of upgrading both of my master cylinders : front brake and clutch.

The clutch is the more important for me : I am not really impressed with Magura. I had a 990 adventure where the slave failed me, then the master cylinder. More than ten years after I bought my 701 and it is quite sad to find that the same issues occur... I got an Oberon slave, I rebuilt my master but after 3000km I think it starts to "stick" : sometimes my lever does not come back fully with a mushy feeling, I suppose it's time to rebuild the master again. I do not want to buy another rebuild kit and I am looking for master replacement options. The issue is that the Magura HC1 has a 12mm piston, and I am happy with the smoothness and the force needed. The smallest brembo I found was a 14mm and I am afraid that I could need more force to activate the clutch (~40% more surface). Has anyone replaced its master cylinder?

Then concerning the front brake after the brake pads replacement I found it good but not as good as my previous superduke. No problem to lift the rear wheel but on steep roads with slow corner I come often to full hand brake grabing.
From what I found the master cylinder has a 20mm diameter and the calipers are 4 pots 34mm diameter. The 690 duke R has far better brakes from what I have heard, with a 15mm master cylinder and 4 pots of 30mm diameter (brembo M50).
In order to get the same ratio as the duke R, I could go with a 17mm brembo RCS : what do you think about it? The other option could be to get the braking setup of the 690 duke R (master+calipers) but it will be more expensive and complicated.

Thanks!
 
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Hi, i doubt your data is correct quote: “ From what I found the master cylinder has a 20mm diameter and the calipers are 4 pots 34mm diameter.“ unquote

But i may be wrong, please proof so..

As far as know the pump is 15mm and the caliper pistons 30mm or 32mm, i stil have to measure mine if i find the time…

In time, i will fit a SET of HC3 pumps, both for brake and clutch, sexy as hell imho… not cheap though..
 
I am not sure of my data either, I have not measured anything. I have read in different places that our caliper is 4 34mm piston, but they may be wrong. For the master cylinder the only information I have is that there is written "20" on the back.
20mm master with 34mm piston is also in line with a feeling a bit "wooden" : the lever is very stiff but it lacks feeling for my taste.
 
Harold J. said:
In time, i will fit a SET of HC3 pumps, both for brake and clutch, sexy as hell imho… not cheap though..
Click to expand...
Considering the (lack of) quality of the stock magura master and slave (both on the 701 and my previous 990) I would never buy a Magura master cylinder as an upgrade.
I would go for a Brembo, accossato, galespeed, or Hel before I would even look at a different Magura.
 
nampus said:
Considering the (lack of) quality of the stock magura master and slave (both on the 701 and my previous 990) I would never buy a Magura master cylinder as an upgrade.
I would go for a Brembo, accossato, galespeed, or Hel before I would even look at a different Magura.
Click to expand...
HC3 quality is beyond discussion IMHO, and a complete different range…HC1 is a budget series..
You can not blame a while company on one product in one range…

There are also 2 different fluidtypes used in the same hardware, Magura do have a mineral type of seal/piston kit and a DOT4 seal/piston kit, for the same HC1. both will fit 100% but are made for specific fluids
Maybe, just maybe something did get mixed up “somewere” , not ok, but possible..

Slave cilinders even of Brembo manufacture, have more often a tendency to have issues..
On Ducati for instance.. i had a monster S4R same issues and that was not Magura..

In the aftermarket range from Brembo, there isn’t a 12mm clutch version available at this moment..
 
NToxx said:
I am not sure of my data either, I have not measured anything. I have read in different places that our caliper is 4 34mm piston, but they may be wrong.
Click to expand...
In the Brembo catalog it looks like a 920B69065 model/type and those are with 4x32mm pistons..
Gues we have to wait till someone does measure them in a vit/svart
 
I would give them a call or email to see which master would work best for you. I have an RCS 19 on my vitpilen 701 and it is true 1 finger braking but that is also using dual m50 calipers so it would not work for your application. The RCS master is an upgrade performance wise but the nipple for the resivour is different than the stock one and will require a custom bracket or a new resivor. If you just want a guesstimate I would see what supermoto 690 guys are using.
 
I think I was wrong and that the caliper is indeed 32mm piston. Replacement parts for our caliper is 76013019000 and are listed as 32x20mm pistons.
With 4 30mm piston on a single caliper the 690 duke use a 15mm master.
My bike is a 2018 and here is the backside with the "20"PXL_20240304_180152374.jpg
 
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OK, so we have 4 32mm piston for the caliper, and a 15x18 master cylinder. It seems pretty spot on, I don't know if a 15mm RCS master cylinder will be a clear upgrade
 
No…. Racing spec pumps and calipers are “only” lighter and do function better in racing conditions i.e. cope bettter with heat.
And look good, but for street use not better performance…

Racing spec pads is even worse on the street, they don’t get hot enough, so brake less on road use..

Try the organic pads for better braking, brembo carbon series, the blue pads..

If you really need another “feel” a 4x34mm caliper might help…
 
So if I resume our 701 brakes are quite close to the duke R : 15mm radial master cylinder (18mm offset for the 701, 19mm for duke R from what I have read, not easy to check).
And 4 32mm piston calipers, vs the 30mm of the Duke R (but monobloc).
Has anyone tested the duke R? If so, is the braking better or not?
For the clutch I think I will go for a brembo 14 RCS, with the adjustable ratio which could correct the higher diameter piston.
 
NToxx said:
For the clutch I think I will go for a brembo 14 RCS, with the adjustable ratio which could correct the higher diameter piston.
Click to expand...
Really? 14mm adjustable is adjustable in range 13-14mm. So 1 mm too big for the clutch, which is 12mm
So it will become even heavyer to operate than the original unit..
 
I know, I would have preferred smaller diameter but the brembo line does not go lower than 14mm I think. It will also come with a lever longer than our two and a half finger lever on the HC1, increasing the mechanical advantage.
Or I may simply throw another rebuild kit on the Magura, hoping that it could last more than the first one.
 
You need to buy the proper rebuild kit for use with DOT4 as Magura has 2 different rebuild kits available (also one for mineral oil and therefore different type of seals)
Be sure your dealer supplies the RIGHT one…

Husqvarna did choose for a short lever, but magura has also a longer lever available.. for the HC1

I replaced mine with it.
IMG_5726.jpeg
 
Harold J. said:
No…. Racing spec pumps and calipers are “only” lighter and do function better in racing conditions i.e. cope bettter with heat.
And look good, but for street use not better performance…

Racing spec pads is even worse on the street, they don’t get hot enough, so brake less on road use..

Try the organic pads for better braking, brembo carbon series, the blue pads..

If you really need another “feel” a 4x34mm caliper might help…
Click to expand...
This one? Are they better than the original?
 

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yup! the blue ones!

softer, so braking better. they do wear a little quicker though

also "breaking" them in needs to be done carefull... the first 100 km, NO hard breaking! build it up in stages... (the heat)
too much heat to soon and pads will "glaze" (as will every compoud will do if not braning in propper)

i always, use emery paper fine like 600, on the brake disks just before fitting new pads... this will help breaking them in and as a precaution to glazing.
take the emery paper between your vingers on both sides of the disk and just turn the wheel a few times (wheel in the fork off the ground) until they get a little matte surface
 
The most important step is indeed to change the pads, the difference for me was like night and day. Every manufacturer has in it's range a performance street pads.For me it was CL brakes XBK5.

Like it is said before do not use racing pads for street use, they are not that good when cold.
 
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