Looking for info on landing gear options

[Luked 71]

I'm trying to sort out the landing gear setup I'm going to use. First of all, I would guess that the gear I have is what originally came with my MKIV kit, but I don't know that for sure. It's the bungee style.

 

I searched for information on dimensions, but couldn't find where anyone mentioned the stock dimensions. The width on mine is 60" from tire center to center. The front tube on the landing gear legs looks like it's about 24" tall. Is this a stock setup?

 

If this is the stock gear, I'll probably look for other options since I've got zero tailwheel time, and want to increase my chances of keeping the plane in one piece. I've read that the wider gear makes ground handling a little easier. Here are some pictures of what I've got.

 

  

 

Last picture is the step on the gear leg. So, what do the experts say?

 

Thanks,

Luke D.

[Av8r3400 1179]

Looks like the Avid produced "Bush" gear to me.  Taller and wider than the stock bungee gear, which is nearly vertical from the side stringers.  It will serve you well as is.

 

I'm a huge fan of the Grove spring aluminum gear.  Pricy, yes, but totally worth every penny, IMO.

[lostman 198]

I haven't flown the bungee gear but echo that sentiment that the grove gear really make for a nice landing gear setup. I haven't really "plunked" mine in but it sure does nice at smoothing out a landing so far. The grove gear is pricey though, but if you compare it to rebuilding your plane every couple years it will pay for itself.

 

Good luck with the project!

[C5Engineer 1170]

Or..... Sorry guys... On with my rant You could always get some proper tw training that truly teaches you the fundamentals and learn to fly your plane as is rather than putting a bandaid on an underlying problem. They require a little bit of attention but there are hundreds of them with many hours on them with the stock gear. Lots of other places to dump a grand into at that point in your build....just my 2 cents... Flame suit on

[Luked 71]

Thanks guys. The Grove gear is nice, but out of my budget, and I'm trying to save every pound I can (within reason) since my engine will be a little on the heavy side. That's great that these are a step up from the stock gear. I didn't know Avid made a factory "bush" gear. I've read about most of the after market gear options in the archives.

[akflyer 1427]

That is not the avid wide bunjee gear. The avid heavy duty wide gear (that I thought was stock on all mk iv) is 27" from the axle to the fuse and 70" wide at the brake backing plates. This gives you around 76 or 78" wide track when on wheels.

[Luked 71]

Or..... Sorry guys... On with my rant You could always get some proper tw training that truly teaches you the fundamentals and learn to fly your plane as is rather than putting a bandaid on an underlying problem. They require a little bit of attention but there are hundreds of them with many hours on them with the stock gear. Lots of other places to dump a grand into at that point in your build....just my 2 cents... Flame suit on

 

Yeah, I agree, and will get some training when the time comes. I just kinda wanted to figure out what I have, and how it compares to other options.

[Luked 71]

That is not the avid wide bunjee gear. The avid heavy duty wide gear (that I thought was stock on all mk iv) is 27" from the axle to the fuse and 70" wide at the brake backing plates. This gives you around 76 or 78" wide track when on wheels.

 

Hmmm... that's definitely not what I've got. Bummer!    Are you saying this is actually the basic stock Avid gear?

Edited 20 Mar 2014 by Luked

[IFMT 36]

That looks like standard Avid gear. I put the wide gear on and it helps. Bigger help in keeping it straight is lock your tailwheel pin! Check airdales old site,http://www.airdale.com/widegear.htm

[C5Engineer 1170]

Welcome to the forum btw! Please post up what your working on, plans, goals, and an intro when you get a chance.

[Luked 71]

That looks like standard Avid gear. I put the wide gear on and it helps. Bigger help in keeping it straight is lock your tailwheel pin! Check airdales old site,http://www.airdale.com/widegear.htm

 

Thanks for the link. I hadn't seen that picture before. The picture of the stock gear looks a lot like mine. The angle looks pretty similar.

[Luked 71]

Welcome to the forum btw! Please post up what your working on, plans, goals, and an intro when you get a chance.

 

Thanks for the welcome. I actually posted an intro a little while ago  I also started a build thread, but it's kind at a stand still right now. I sent my crankshaft to Aircraft Specialties, and I'm just waiting to hear back from them if it's any good. This project will probably be a fairly slow pace because of time and money (hopefully not too slow though). You can find my project in Avid Mk IV under "Lukes MKIV Project".

[akflyer 1427]

I like the heavy duty wide gear for more than one reason.  My plane was wrecked twice before I bought it due to the gear folding up on the stock gear.  plus the narow gear is just not as forgiving.

 

[IFMT 36]

Always due the seat truss upgrade if you change the gear. Wide gear exerts a greater moment arm and thus your seat will get way lower with a little harder than greased landing. Just get the heavy tubing change up. Plywood glued in isn't worth the effort. Do it before the fabric. 

[6320012s 12]

I'm a fan of the grove gear only because it puts the wheels wider and about 4" forward of the origninal.  Between the grove gear and fixing the brake pedal geometry, I can land on pavement with confidence.... However, too many agressive landings may have stressed the clamping bolts/nuts.  When doing the post mortem, it appeared the nuts stripped off the right clamp leaving the clamp nowhere to be found and a wild ride on touchdown.  When I get back in the air, it will be with 3/8 bolts instead of 5/16 with two nuts instead of one. 

[Luked 71]

Always due the seat truss upgrade if you change the gear. Wide gear exerts a greater moment arm and thus your seat will get way lower with a little harder than greased landing. Just get the heavy tubing change up. Plywood glued in isn't worth the effort. Do it before the fabric. 

 

Someone already added gussets into the seat truss. Looks like they are about .040" steel. Is this what you mean, or do you mean to replace the existing seat truss with one made out of heavier tubing?

 

166, Sorry to hear about your accident. The Grove gear is nice, but I want to avoid the weight, and the cost. Nice looking Kitfox.

[dholly 718]

   Luked!

 

No doubt in my mind the gear you show is stock oem bungee gear supplied with 'most' Mk-IV kits. I say 'most' only because sometimes models overlapped, parts availability to the factory was not always 100% and kit buyers sometimes specified or omitted some kit components. As a result, Avid may have shipped something different than the 'standard' component itemized on the pull sheets. Check the pull sheets you received along with your kit.

 

If you don't have these, I posted a copy of mine in the Avid Mk-IV Forum that you can refer to for an inventory check of what you have. I also am attaching a pic of my old Mk-IV kit showing the same main bungee gear legs with the integral peg step. The Mk-IV gear legs were heavier and more heavy-duty than the 'standard' bungee gear supplied with earlier B-C models, which did not have a step.

 

The successor co. to Avid Aircraft, the [old] Airdale Aircraft, developed and sold the W.I.B. (wider-is-better) bungee gear for tail draggers. They also included this as standard main gear for their complete Avid+ tail dragger kits (Fat Avid upgrade kit buyers either used their existing main gear or paid extra for this option). In addition to increased height and width, the tubing i.d. and wall thickness of this gear was also increased and the peg step was changed out to a ledge step. The same W.I.B. gear is pictured on the [new] Airdale Sportplane website and will bolt right up to your Mk-IV. I've attached a pic of the W.I.B. gear supplied with my Avid+ kit.

 

Enjoy your Avid build, please share your progress pics!

[dynomike 91]

I fly mine with the stock gear off of a paved runway and actually love the way the bungee gear is so forgiving. it just eats up any bounce, and as a new tailwheel pilot like myself is really nice in my opinion.

[IFMT 36]

I might accept steel gussets if it's done right. The change up truss from airdale is way beefier than the original. I would have to measure it again. More bracing as well. Cost around 200-250 for the piece. Getting it tig welded in was the big expense.

[Luked 71]

Thanks dholly for the detailed explanation and pictures. That was super helpful. I'm starting to understand the differences now. I've got to run for now, but I'll read through all of this again later today.

 

dynomike, thanks for the information. gives me something to think about since TW will also be new for me.

 

IFMT, thanks for the clarification. It seems like the beefed up tubing would be better too since it would resist out of plane bending in all directions rather than just the plane that the plates are installed in. Also, the plates have a fair number of cutouts for controls. The beefed up tubing wouldn't need that. The plates are already welded in though. I'll have to think about that one.

 

Now, I've got to take off for a while. Thanks again everyone.

[Bandit 286]

If you learn to fly the airplane the Airdale Spring gear works great. Much better handling on the ground. Fly it on to the runway! The hell with the full stall 3 point landing! If I hit hard I would rather replace the gear rather than rebuild the whole fuselage.

Edited 21 Mar 2014 by Bandit

[Luked 71]

If you learn to fly the airplane the Airdale Spring gear works great. Much better handling on the ground. Fly it on to the runway! The hell with the full stall 3 point landing! If I hit hard I would rather replace the gear rather than rebuild the whole fuselage.

 

The Airdale spring gear looks pretty good. I think if I could choose exactly what I want, I would probably get the their WIB gear. Has anyone bought anything from Airdale in the last few months? Or, does anyone have a set of WIB gear they want to sell?

[Luked 71]

Okay, sorry to keep posting all these questions, but I've searched and haven't found all the information I was hoping to find  .

 

My seat truss (MK4) has a 5/8" x .035" wall tube across the top, and all other tubes are 1/2" x .035 wall. Someone added .040" gussets in the triangular areas, but the welds are pretty rough, they actually burned through the tubing in at least one place. I'd like to replace the whole seat truss.

 

I'd also like to go with a wider gear like the WIB gear (tail dragger flying will be new for me). Does anyone have pictures or information on what type of seat truss upgrades they have done to use the WIB gear? I've done some basic truss calculations, but just want a little reality check before committing to a design. I'm also trying to minimize weight, so I don't want to overbuild this. I've been waiting to order tubing until I can nail this down, but I'm getting impatient to get this gear situation knocked out.

 

Thanks

Luke D.

[SuberAvid 617]

The Airdale recommended reinforcement of the seat truss was to cut pieces of the 1/8 microlam plywood to fit in the open areas of the seat truss and glue them in place with T-88 epoxy.  I did this when I installed the WIB gear on my MKIV and never had any problems with it.

[Luked 71]

I didn't know the plywood reinforcement was enough for the WIB gear. That's good to know. Earlier in this thread, IFMT suggested a beefed up truss like the one he bought from Airdale because he had bent his original. I wonder how his replacement truss compares to the plywood add on.

 

I did some calculations on some different truss designs with different tubing sizes. The problem is that I don't know how much force the truss should be able to handle (how hard of a landing to design for). The best I could do was try to reverse engineer the existing truss, and then design a new one that can handle more force at the bungees. I hope I can at least proportion the members in the truss to match each other so that I'm minimizing the weight. I guess I'm just over thinking this. Thanks for the information though.