Bike wheel setup

[XL-C-100]

For those of you out there that are running bike wheels on the legal eagle can you tell me how the axle is setup? I am building an XL so my plans don't call for bike wheels but I put them in with the axle and bearings the same way they would be on the bike. I am worried about the strength of the bearings and the axle? I am thinking of drilling out the wheel and putting in a bushing and a heavier axle?

[Cessna4542c]

I thought about doing the same thing with the bushings  but I needed to have the wheel tight with no play because of using disc brakes. I called a bushing company on the Internet and gave them the inside diameter of the hub and the outside  of the axle and they matched it for a bushing. I used to spacer between the two bushings and threaded the axle to make the wheel tight. Seems to work good.

[Tom H]

On LEU Treehugger, we used a 3/4" 4120 tube as the axle - heavier wall than the common 0.035, but not sure how thick.  I remember reading of bent axles on LEUs prior to making the gear.  We never had a bent axle, but did bend the main gear legs from hard landing impacts.

The wheels were high quality plastic spoked wheels, purchased from a bike shop.  I believe we drilled the hubs out so the bushings would fit, but we may have selected bushings to fit the existing bore - just can't remember.  The bushings were scintered bronze flanged bushings with 3/4" ID, OD may have been 1".

We drilled the end of the axle tube to install a cotter pin.  Put washers on inner and outer side of the hub.  We did not have brakes - brakes are for sissies.  As long as you have plenty of clear space ahead, and grass helps. 

May be able to make the washers correct thickness to eliminate side/side play, but Cessna4542c's method of threading end of the axle would work great, and install castle nut (maybe faced to make it thinner) w/ cotter pin.

[XL-C-100]

Thanks for the response, sounds like it would be a good idea to abandoned the bearing and axle that came off the bike. I am concerned with the additional torsional load on the bearings because it is not supported on each side of the axle like it would be on a bike. 

Another concern of mine, I have been checking out pictures of other builds and the location of the axle. Some seem to bring the location of the axle forward and others seem to bring it straight out of the gear fitting (90 degree angle from bottom of fuse). I know the plans say the axle should be even with the leading edge. My problem is that at the time I built my landing gear my wings were not finished so didn't know where the leading edge was. I built them with the leg straight as I had seen others do and now I am worried about ending up on my nose!

[stevejahr]

I might worry about the axle but never about the bearings.  Bike wheel bearings take a fair amount of lateral loading as the rider tosses weight around for pedalling and manuevering.

Note that there *are* larger and smaller bike axles out there.  The BMX boys often use larger axles which may well be able to handle what a LE has to dish out.

Another option is to lace up your own wheels using hubs for a recumbent trike.  I have a set of these with bearings and disk mount flange that will find their way into a project someday.

[Dan_]

Another concern of mine, I have been checking out pictures of other builds and the location of the axle. Some seem to bring the location of the axle forward and others seem to bring it straight out of the gear fitting (90 degree angle from bottom of fuse). I know the plans say the axle should be even with the leading edge. My problem is that at the time I built my landing gear my wings were not finished so didn't know where the leading edge was. I built them with the leg straight as I had seen others do and now I am worried about ending up on my nose!

Attached is a rule of thumb...  Also shows axle lined up with leading edge, several contributing factors...

[Dan_]

Attached is a rule of thumb...  Also shows axle lined up with leading edge, several contributing factors...

Another attachment explaining how to find the vertical component of CG

[joecnc2006]

If you look at the note on the plans it says "Center of axle should align with wing leading edge when plane is in level condition OR 6" FORWARD".  Which will give you the 12° sweep forward which is normal. That is how i placed mine close to the 6" since my wings are being build towards the end of the build, I wanted the fuselage and everything else built first since this is the main attachment for everything.

[XL-C-100]

The decision to abandoned the original bike wheel axle and bearings was made for me! When I was rolling the plane back into the garage I noticed the right wheel axle was bent (no use yet just me sitting in it and test running the engine).  First I though no problem I will pull off the wheels and drill them out and slide some bushings in. Not so easy the bearing races are some hard stuff, I ended up taking it to a local machine shop. They machined out the bearing races and pressed in a flanged bushing and a sleeve so I could put in a 3/4" axle.

Still unsure about how my landing gear CG will come out. It seems from looking at pictures of the Legal Eagle as opposed to the Legal Eagle Xl that the gear had straight legs on the LE and then when to a more forward profile with the XL. True? Does this have to do with a change in the fuse dimensions?