For those of you who have had the pleasure of spec'ing your brake systems yourself, with big bushwheels in mind, what size brake line did you choose?

I've already installed my 9/16" bore master cylinders (down 1/16" from the 5/8" standard) which should give a little more pressure. As far as the line from cylinder to caliper, some people I've talked to say it really doesn't matter what size brake line you use, there is no advantage either way, and to go smaller to save weight. All that matters is the flexibility (or lack thereof) of the line.

Unlike fuel, the inner diameter of the line doesn't affect the pressure that's exerted by the piston at the caliper, since we're talking about static pressure, not flow. Once the line is primed, the incompressible fluid can be considered a hard material and it matters little whether you push with an AN3 bolt or an AN4 bolt, for lack of a better metaphor.

That's my understanding, anyway. I'm just curious if someone has found anything regrettable about going with the smaller lines. Did you use hard lines too, or all hose?

Z

Piper uses #4... Probably what I would go with because I am used to it... Try to keep the fittings down to a minimum.... Less points to leak the better... I like to use one long braided line on cubs..

Brian

I switched from 1/4" nylo flo to 1/8". Saved a little weight and it's more flexible. I also heard it doesn't expand as much so more pressure to the calipers? For having 29's and single calipers, my brakes work pretty good.

I used -3 lines with -4 fittings. Best of both worlds, smaller lines are more flexible and lighter weight but the -4 fittings are more "standard." You can get these from TS Flightlines or Bonaco in whatever custom length you want.

You are correct, the inner diameter of the line doesn't matter much (unless it's really small) because its static pressure.

Greg

Z
Matco has been promoting the use of 1/8" brakeline instead of 1/4". I talked to a couple of guys that switched and they said it was SO much easier to bleed; Air cannot stay trapped in the line no matter if one is filling from the top or the bottom and does not matter if there are high spots in the line. That is what I bought from my CH750 build.
I also bought Matco's "Intensifier" kit which is just a sleeve to decrease the bore size of the master cylinder. Haven't flown yet, so that is all I can tell you.
Cheers,
Joe

Thanks for the input everyone.

Going with -3 lines.