so i went to build the brake lines the other day, and i realized a few things.  the plans have you building an aluminum hard line from the fitting at the gear leg root, down the leg, making a big loop at the wheel assembly, then connecting to the fitting on the caliper.  as i was building this line, i realized that the big loop at the wheel assembly is sort of like a spring,  because the caliper moves when you apply the brakes.  it’s funny, because these are things of which i’m keenly aware (from car stuff) but never occurred to me until now.  so as i’m looking at my first rough fitting of the aluminum hard line, i’m starting to see what forces would be at work here while braking and bouncing down the runway.  it seems like there’s maybe a better way to go for these lines.  now, i’m not saying that the “per plans” built way is unsafe.  there are tons of rv’s out there flying around with this very setup.  it also has the advantage of being very light, simple, and inexpensive.  all good things.  the thing that made me decide to get different lines built is that there’s no nosewheel steering with the rv-10.  the nosewheel casters, and you steer with differential braking at low speeds, and with the rudder at higher speeds.  should you have a brake line failure on rollout, it’s possible that you could lose control of the aircraft.  it’s pretty unlikely that this’d happen, but it could.  with the aluminum hard line flexing back and forth every time you apply the brakes, it could eventually lead to cracking and failure.  now, just to be clear, this is pure speculation on my part, based entirely on the goo between my ears.  these are just things that i think... i don’t know anything.   so armed with this bit of pure speculation, i set about ordering a couple new lines that would fit the bill. i found a place called Bakerprecision in nearby long beach, ca that would build me some teflon brake hoses at the length i needed.  i also had them use stainless fittings to round out the package and give some extra durability.  i measured with some rope and figured that 31.5” was going to work, and instead of making a loop around the underside of the wheel assembly, i’d just go aft to the caliper from the front of the gear leg, with a little excess for wiggle room for the caliper.  i got the lines the next day, and they fit!  cool.

cost: approximately $30 each - total $60

weight:  original aluminum lines & fittings = 1.8 oz each

weight:  new teflon & braided steel lines = 3.6 oz each