NC35 Master Cylinder Upgrade

[gavins]

Yeah could definitely be that. did they have any weeping of fluid from the washers?

No, not visibly.

Another thing to check is that your discs aren't slightly warped, could be pushing the pistons back in slightly on each rotation and would be more noticeable at speed.

[dazmoto]

Any 17/19mm master cylinder if u go radial it might catch on clocks pads duel carbon sbs but don’t use in the wet they lose Preformance get some hh for the wet

[magg]

Would not warped discs give a pulsing lever under brakes? You have a non OEM adjustable lever, you adjusted the free play and still have too much travel. Is not free play the same as travel before the pads touch the discs?

[SPOONDIDDLY]

Would not warped discs give a pulsing lever under brakes? You have a non OEM adjustable lever, you adjusted the free play and still have too much travel. Is not free play the same as travel before the pads touch the discs?

The problem isn't that there is free play, the problem is that the travel is long and feels as if the piston in the master cylinder isn't moving enough fluid to the calliper for each mm of travel compared to more modern bikes that I have ridden. The initial application of force to the disc rotor occur immediately, however the level of force is less than I would like.

When the bike and braking system is cold and you spin the wheel on the stand or are riding at low speed the stopping force is applied within 1/3 of the lever travel, however once the bike has some momentum I need to pull the lever significantly further. This isn't a major issue early in the session as it gives me plenty of room to modulate the brakes as I see fit without overdoing it.

[magg]

Your description sounds like a spongy lever and a pad material that offers a low coefficient of friction. My NC30 has a hard lever and the pads bite enthusiastically with a light lever pressure even though the pads are not sintered.

Maybe you do have air in the system.

I find that brake bleeding works best: with calipers and master cylinder off the bike and positioned to place the master cylinder at the highest point and horizontal, and the calipers such that any trapped air can flow directly from behind the pistons, I put a block between the pistons the same thickness as a disc and pump the pistons out until they butt against a block, then I force all the pistons back into the calipers.

The large flow of fluid appears to help expel any trapped air up and out the master cylinder. Hope my description makes sense and helps.

[SPOONDIDDLY]

Yeah I will need to give the full system an overhaul it seems.

Now back to the original question regarding master cylinders - what models have people had the most success with and would recommend?