LEU & LE XL Bent or Damaged Landing Gear Pictures and Informaton send my way.

[rockiedog2]

Hi Joe,
 
I love it.  Man the LE aint no combine and I think Weasel said he went into a corn field that had been cut already.  That bird looked like it belly flopped in and tried to use the prop as a blender.  Holy crap, the bird is tougher than nails.  You sure wouldn’t get away with this least amount of damage in a Mini-Max or too may of the other competitor aircraft flying today.  Leonard sure knows how to design a tough bird.
 
I can now see why the gear loves to bend like an elbow when hitting the ground.  Your explanation is great and it sheds light on what forces are impacting the various gear members and constantly bending them in similar ways.
 
I am glad you included the tail wheel along with this.  I like your design and I know I can maybe do that too.  It looks light weight, basic straight forward solution to a problem and durable as a nagging wife.  I don’t have one of those but I have heard that to be so.
 
I have spent a lot of time over at the Yahoo site and I am still learning how to slide around over there. I am concerned about losing all the information contained there.  It truly is a treasure trove of good information that supports the reasons for the changes that have occurred over the years.
 
So Joe, you would go with the 20” Murray wheels and disc brakes over the Black Max wheels?  The people at Black Max said the guestimated weight of the system is around 13 pounds total.  I am figuring on 14 pounds and that would be what I would use in comparison.  I don’t remember any weight expressed on the bike wheels with brakes.  Does anyone have a feel for what that might be?
 
I thank all of you for all this great information.  I am fairly sure regarding the tail wheel direction but I am still in a deciding mode on the mains.
 
Joe, is that tar an all terrain tread or a snow tread?     Joe, is the spring a cut down leaf spring from the junk yard?
 
Thanks,
 
John
Hi John

Ebody I know who has the Black Max likes those. They are definitely top of the line. The down side is the cost and a little weight and I suspect higher drag. The complete bike wheel setup with mountain bike brakes weighs 10# the Black Max not that big of a weight penalty over the bike ones unless you're fanatical. I am. That's with the thorn proof tubes which are a bit heavy. Go with regular tubes and maybe 9# rounded off. The cost diff is big about 300$ diff but you only gotta spend it onetime so if I wanted the Black Max I wouldn't let that hold me back. If I had it and could spend it. There is a 4.00x6 Black Max setup that I put on this new thing I'm building that wud be good on an Eagle but doesn't quite have the good looks of the 600x6 that Sam is running. I wonder if that is the 13# setup that Black Max quoted you on the weight of. The weight and cost favor the bike wheels the looks and durability favor the Black Max. And the flotation...(Sam doesn't have any springs except his tars)...if doing a lot of off field landings that favors the Black Max too. No doubt for my use the bike wheels. they are part of the climb performance package on my plane. And they are tough but not good for soft ground. But I do operate off grass. sometimes soft and slick. I just go anyway no probs. Your call...
The tailwheel spring has been lying around here for a couple decades i dont know what it came off of. Its pretty common except its 3/16 thick. Most are 1/4.
Thats about all I know about that.
Spencer

[rockiedog2]

I consider the Black Max tires with solid struts to have equivalent shock absorption to the sprung struts with cycle tires. The low pressure tires absorb a lot of energy. I run a max of 10 psi in the Carlisle tires, and flew an entire summer with nearly no pressure. The sidewalls were stiff enough to support the plane but it did wear the outside edges of the tread.

Sam, I plan on landing mostly on grass strips around where I live and wondered how much you land on grass. Coming from an RV-9A that doesn't tolerate rough fields I sure don't want to stand the XL on its nose. I really like your setup but concerned about the small diameter of the tires verses the bike wheels.

either one will be fine for grass strips the Eagles aren't bad about wanting to nose over at all. i ran 600x6 lawn mower tires and wheel on mine before going to the bike wheels no prob with either one unless in mud. then neither one is good Spencer

[Jlwright]

I guess I've got some time before I decide for sure on the wheels, but it's good to know I have options.

[Sam Buchanan]

I consider the Black Max tires with solid struts to have equivalent shock absorption to the sprung struts with cycle tires. The low pressure tires absorb a lot of energy. I run a max of 10 psi in the Carlisle tires, and flew an entire summer with nearly no pressure. The sidewalls were stiff enough to support the plane but it did wear the outside edges of the tread.

Sam, I plan on landing mostly on grass strips around where I live and wondered how much you land on grass. Coming from an RV-9A that doesn't tolerate rough fields I sure don't want to stand the XL on its nose. I really like your setup but concerned about the small diameter of the tires verses the bike wheels.

Jim, I occasionally land on grass but don't know how relevant this will be to your situation. "My" airport has grass areas that are often used for landing zones and these areas are not groomed, just regular ol' pasture grass that is mowed down to a foot or less. The ground is rough and the XL has never had any problem with it even though the pilot gets bounced around some due to the lack of sprung struts.

The plane has never even been remotely close to tipping over. I just can't think of any disadvantages to the Black Max system--if the field is too rough for those low pressure tars the plane has no business being there....

I like not having to be concerned about side-loading on the tars like I would be with cycle wheels. The Eagle purists emphatically endorse cycle wheels, but look what Leonard designed the XL to use.....  

[Bob S.]

Only one THAT I KNOW OF that has stood an Eagle on it's nose is Spencer....

[Sam Buchanan]

I guess I've got some time before I decide for sure on the wheels, but it's good to know I have options.

You need to have your decision nailed down before building the gear legs, the Black Max gear is taller. There is an error in a major dimension for the gear on the XL drwgs, let me know when you get there.

On second thought, here it is:

http://eaglexl-58.com/gear.htm

Scroll halfway down the page and look for the italicized note on the 17.5" dimension on drwg 22.

[Jlwright]

Thanks Sam, I am sold on the Black Max setup with hydraulic brakes.

[Sam Buchanan]

Thanks Sam, I am sold on the Black Max setup with hydraulic brakes.

The brakes are superb, only take a few minutes to rig, and never need adjusting. Being able to have a reliable parking brake is an added bonus:

[Jlwright]

The parking brake is a big plus as far as I am concerned. My Champ didn't have a parking brake and I always had to find a place to tie it down before starting and sometimes that just wasn't possible. You can see by my avatar what kind of brakes I had on the Airbike. (Nike) Some day when this global warming is over I want to meet up with you and see your XL.
Jim

[CHARLES DEBOER]

Sam, I don't understand why you would ignore the 17 1/2" dimension when the drawing says on pg. 22 it is for use with the 6" Black Max wheels on pg. 28 of the drawing package .  I have built mine using Hagar 4 X 6 " wheels and the 17 1/2" dimension and the gear leg measurements came out different than the drawing.  I don't recall what those dims. are so I'll have to get back.  I went with my gut and figured that the 171/2" level upper longeron was the key dimension for a 6' wheel.

[Sam Buchanan]

Sam, I don't understand why you would ignore the 17 1/2" dimension when the drawing says on pg. 22 it is for use with the 6" Black Max wheels on pg. 28 of the drawing package .  I have built mine using Hagar 4 X 6 " wheels and the 17 1/2" dimension and the gear leg measurements came out different than the drawing.  I don't recall what those dims. are so I'll have to get back.  I went with my gut and figured that the 171/2" level upper longeron was the key dimension for a 6' wheel.

Charles, you answered your question.

When the XL gears legs are built per plans and configured with the axle spacing shown on the plans, the 17.5" dimension is wrong. I suspect it is a holdover from the LE plans for the much larger diameter cycle wheels. You made the same discovery I did when you used small wheel and found that 17.5" won't work with the XL gear legs.

I built the XL gear legs per plans, aligned them per plans....and ignored the 17.5" dimension.

[Sparrow]

Hi Guys,
 
I have been on the Yahoo site downloading all the information I could find and going through it.  I don’t want to be asking questions that all of you have already answered.
 
I do like the bike setup but I must give into Leonard and agree the Black-Max, although it is costly and heavier, is still an improvement.  I do agree the side loading issue is gone away with the smaller diameter tire.
 
I will run an analysis of the geometry.  I was not aware of issues.  Regardless, there has to be a target distance between the bottom of station 2 and the ground with the fuse level.
 
I have come to understand that one just matches things up, stand back and eyeball it and if it looks OK it is good to go.

[CHARLES DEBOER]

I started with the 17.5 inches from the center of station #2 bottom longeron in accordance with drawing #22 but my gear legs were shorter than the dimensions on pg. #23.  My front leg is 21 in. vs 24 on drawing.  The rear leg is 35.5 in. vs 36.  And the shock strut is 22.75 in vs 24.5.  As long as the height from the center of the axel to the center of the longeron at station #2 is correct and the center of the axel is even with the leading edge of the wing (aprox. 6 inches forward of station #2 center) when in level condition, everything should be fine.

[rockiedog2]

 >>> I do agree the side loading issue is gone away with the smaller diameter tire.

I've run the bike wheels on mine for probably about 200 hours and as far as I can tell there is no side loading issue. You will roll the tires off the rim before you damage the wheel unless you crash the thing sideways like I did. In all crosswinds that the plane is capable of handling the wheels are fine. And for the expected swerves etc no problem.  No probs at all with sideload in my experience so if that's the deciding factor in your decision then you might wanta know. Operationally either one is fine it boils down to buying the one you like the looks of the best assuming you're willing to accept the weight cost and drag penalty of the very fine Black Max
Joe

 

[CHARLES DEBOER]

Side loading is not an issue on XL-67 because I am still working on engine installation. BUT, I have ben flying an Ascender II (Pterodactyle), mfd. by DFE aircraft, for 12 years with the same 20 inch wheels and have had zero problems with side loading on these wheels.  This ultralight is a two access aircraft requires landing into the wind if cross winds are above 5 to 8 knots.  I have been force to land many times with a quartering cross wind at 10 and 12 knots with severe pucker power in the @#$%.