OZ ATV :: The Australian ATV Forum

[dangerman4]

Hi all
my raptor currently has a 1/2 inch piston in the master cylnder which i think is the standard size.
now my brakes work quite well, but i have to pull quite hard on the lever to get any decent stopping power from them.
compared to the likes of the new 450's can am etc u can get decent braking with 2 fingers.
so im looking to change the master to somthing more powerful.
over on the raptor forum in the states most of them change to late model yfz or 700 raptor masters, but i dont think there is a lot of difference in the actual bore size.
my question is would a larger bore pushing more fluid make it better or worse. or do i need a smaller bore so i have more pressure on less flow?
im confused on the ratio of how this works.

im also interested in looking at a R6 front master as its a radial type master, and should outperform the yfz type for similar cost.

[Quad]

Hi just a question do these front brakes have rubber lines , they maybe swelling up when braking hard, if yes , use a set of ss lines.

I have the same as 700r brakes and have no problem.
to your question use a big master cyl in bore ,more volume to stop.

more fluild to fill the wheel cyl to work right.
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Im not the sharpest tool in the shed

[123boath]

a big piston requires less effort/movement and creates more pressure then a smaller piston doin the same amount of movement.

[doorslammer]

i agree with quad, maybe some braided lines. also check your pads arnt contaminated or glazed, same with the discs
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01 Banshee
Never take life seriously. Nobody gets out alive anyway

[bullet]

To get more braking pressure you actually have to go smaller on the master cylinder.
But it will reduce lever feel inversely (smaller piston = more pressure but longer travel, so it will feel spongier).
steel lines will do nothing for braking effort because they do not change the pressure or mechanical advantage at all.
They will mean less master piston movement is required because less volume is wasted in line flex.
This effectively makes the brakes less spongey and more solid, but you'll still be pulling the lever just as hard to stop.

Some master cylinders will run the same bore sizes but feel very different because of the leverage ratio from your hand to the piston.
Once again more leverage means it will feel spongier, but steel lines will help get rid of the sponginess.
It depends on where the lever pivot is.
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Can-Am X Team
Bullet #Y12. MrsB #Y18.

[dangerman4]

123boath wrote:

a big piston requires less effort/movement and creates more pressure then a smaller piston doin the same amount of movement.

thats the confusing part a bigger cylinder will have more flow but if you have the same leverage factor as standard it would surely be harder to pull on not easier.

anyone know what size the latest atv master cylnders are?
or is the size irrelivant and its all in the leverage point?

and does anyone like the R6 master idea or not?

[cowchaser]

Dam It i'm going to have to agree with Bullet on this one.
I hate doing that!
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Smitty