Clutch master cylinder bore size RCS?

[Rob21]

Hello, seen some of this on the search but after some specific info on Brembo RCS clutch master cylinders to match my brake. I know smaller bore means lighter pull but less action to disengage the clutch. Would a 16 be enough or is the 19 better suited?

 

Bike is a 91 1127 with diaphragm clutch and standard springs.

 

If anyone has used these let me know, Cheers, Robbie. 

[Oilyspanner]

Seem to remember the std m/c being 1/2 inch, which is about 13mm. 16mm is plenty big enough, you might find that you don't need to move the lever very far to disengage the clutch, so would bite pretty late too. I fitted a TL1000R m/c when I altered my controls - that  was marked the same as the std m/c You're right about the increased pressure required for a larger bore m/c, I swapped between a 17mm and 19mm brake m/c several times when I changed the front-end. The 17mm m/c was lighter in action, but there was more lever movement, but it was powerful - the 19mm needed less lever movement, was firmer at the lever and wasn't really any more powerful. The smaller m/c also gave more feel, because of the greater movement needed I guess … bigger isn't always best with master cylinders … plus the clutch doesn't need as much fluid movement as two brake calipers.

[Rob21]

Cheers for the reply mate,

 

I wonder if the 17mm would be the happy medium, biting point could always be fine tuned with push rod lenght? If I’m thinking right on that haha!

[Dezza]

Frando do a 17mm radial clutch master cylinder. Venhill do them. I have one for my hydraulic conversion 1100EFE engine. It makes Jack Shit difference to the weight of the clutch pull though so it's going back to cable for increased parsimony. And less weight.

[Captain Chaos]

2 hours ago, Rob21 said:

biting point could always be fine tuned with push rod lenght?

nope, the slave cilinder moves as far out as needed and the master cilinder compensates for that