Brakes, need larger ones?

[Helidesigner]

I have about 13.5 hours on my plane so far. Things are going well but my brakes are weak. I have Matco units rated for 3300 in-lb of wheel torque. The plane begins to creep at about 1900 RPM on static run up. I have 700x6 tires. For you guys with 540 engines some questions; What kind of brakes do you have? What puck diameter(s)? Can you hold the plane on a full power run up?

Thanks,
Mark
N83ME

[Battson]

I have Grove single puck, the smallest Grove make. They are impotent, but they will hold up to about 2750 RPM now, with my 8.00x6s.
At first, it was as you say, about 1900 and they began to slip slowly.

I am going to upgrade to larger brakes I suspect, as I am about to fit 24" tires (Goodyear's so-called 26"). Althought I did see that the "Roverhawk" was using single pucks and 24" tires at one stage, so maybe it's possible. I will report back.

[Mark Goldberg]

With single puck Clevelands, my BH would drag the locked up tires a little on pavement at a full power run up. That was with 700x6's. Mark

[Battson]

Mark - did you ever try single puck brakes with the Goodyear 26" tires?

[marcusofcotton]

Heli Mark,
Which model number Matco brakes do you have? I was considering Matcos as a possibility, but may need to eliminate that idea.
Thanks,

Mark J

[Mark Goldberg]

I do not believe that single puck brakes will be adequate with the 26" Goodyears. I was told by someone that we should use double puck brakes when using tires bigger than 8.50 x 6.00
I switched to double puck brakes when I went to the 26" Goodyears. Mark

[Battson]

Thanks Mark,

I will be trying those brakes for interest - I will report back, but I am also going to order the powerful double puck brakes too.

[Helidesigner]

I have the Matco WHLWE600 wheel and brake assemblies. (I can not figure out their numbering system). I told them I did not want especially powerful brakes since it was a tail dragger. They recommended this set. It is not strong enough. I should have done some more analysis. That is what I get for an impulse buy at Oshkosh. My brakes only have a max 3300 in-lb wheel torque capability. I estimate I need about 5400 in-lb to hold at full power. I spoke with Matco today and they recommended some more run it time on the pads but it will still not be enough. I calculate I'm getting about 3000 in-lb of holding torque now. I'm not sure if this is my fault or not but I need larger brakes. They recommended a double caliper system which may or may not fit well. I would prefer a double puck system. I'm bethinking about it over the next week or so.

Mark
N83ME

[jaredyates]

Keep in mind that the Bearhawk has a different gear geometry than most if the light taildraggers. Much more of the weight is on the tail, and nosing over is not much of a concern. I asked Bob once if he knew of any that had nosed over, and he did know of one. That case involved a full power static runup with the brakes set. The operator pulled the prop control back while at full RPM, and the big engine and prop had enough inertia to take a giant bite of air and pull the tail up.

[Battson]

In terms of off airport and beach landings in the Bearhawk, you might be more concerned with nosing over in that scenario....
Easy on those brakes on any soft surface, especially beaches. I've personally had a close call.

[Battson]

I fitted the larger tires on Saturday morning, and left the single puck brakes in place for the week (larger Grove brakes still being shipped).

26 Goodyears are great for the Bear by the way, no loss of speed compared to Michelin Aviator 8.00x600's - but the off airport / soft field performance (and cool factor) goes through the roof. I following the tracks of a Cessna which got bogged down yesterday, he sunk 6" into the muddy turf, and I didn't even leave a mark (except tailwheel).



It's fair to say that single puck brakes with 26" tires are totally ineffectual. I need to close the throttle completely to slow down when taxiing, and have no differential braking for steering. During a wheel landing I can apply full brakes and the tail continues to drop unless I use elevator. The words "pathetic" and "pointless" come to mind.

I can still do an 1800RPM run up, only just, but only if the brake discs are warm to start with AND if I increase the power very slowly. With cold (and mildly rusty) discs I couldn't hold 1300RPM of power introduced quickly, to begin with. So the lesson is with 8.50's or 26" Goodyear (24" in real life) tires, double

[whee]

I was just talking to Matco about brakes because I was cruising their website so I thought I'd call. They have the "WI600XLT" triple 1.5" puck brakes that provide 6441 in-lb of braking torque. Their calculator says I need 6200 in-lb of torque for 31" tires, that's a little close for me but the reality is I will likely never run 31s I'll probly be on 29" tires or smaller. Anyone have experience with Matco triple puck wheel and brake set?

I'm still leaning towards double puck grove brakes but until they are installed anything is possible.