Brodhead Pietenpol Association

Original Posted By: "Jack Phillips"
anyone sen motorcycle wire wheels on a J-3 style gear instead of straightaxle?I've got a J-3 gear with 1.25" axle and am trying to find an easy solutionto putting on 18" motorcycle wheels.ideas appreciated.DJ VeghMesa, AZGN-1 Builderwww.raptoronline.comN74DV________________________________________________________________________________

Original Posted By: owner-pietenpol-list-server(at)matronics.com
DJ,If you look in the EAA Wood book, there is a picture of a split axlePietenpol with wire wheels. It is towards the back of the book, in achapter called "Why not Build a Wooden Airplane?" I don't remember the pagenumber and the book is downstairs in my shop.You would have to modify the plans somewhat to change the height of the gearunless you wanted to always make wheel landings - otherwise the Cub typegear with such tall wheels would require too high an angle of attack atlanding, and you could not 3-point it.Jack -----Original Message-----

Original Posted By: owner-pietenpol-list-server(at)matronics.com
Larry,Some things to consider with tall wheels (which I'm using on my Piet).1. Braking can be a problem. Big wheels are hard to stop - airplanes quitusing tall wheels at about the time they started using brakes, and probablyfor that reason. If you use motorcycle wheels, you probably will want touse their brakes as well, unless you just want the brakes to slow you down alittle, not hold it for a runup.2. If you use brakes, you've got to find some way to counteract the braketorque or the axle will spin. Of course, if you use the split axle gearthis is not a problem. It is a big problem with the straight axle. MikeCuy came up with a very clever system of pins welded to the axle and ridingin guides welded to the V fittings that I have copied with pride.3. Motorcycle wheels are not designed to take any side load. Since amotorcycle leans in a turn, all loads are carried radially. For thisreason, motorcycles can get away with narrow hubs and the spokes nearlyvertical. Unless you can guarentee that you will never land while driftingslightly sideways, you might want to consider making wider hubs to give abetter angle to the spokes. I've seen Piet's done both ways, but I've alsoheard of some using stock motorcycle wheels to have a wheel collapse due toside loading. Just something to consider. The GN-1 I flew several yearsago used stock Honda 3.25 x 18 wheels and brakes4. Lightweight alloy rims are available. Go to a cycle shop and ask forMotocross wheels. I got a pair of used aluminum rim 21" wheels for $20. Iwill make wider (6" wide) hubs for them and will use hydraulic Clevelandaircraft brakes.5. Bearings don't need to be elaborate. Mike Cuy uses plain bronzebushings, greased occasionally. I'm going to do the same thing. Motorcyclewheels are designed to run at high speed. The fastest you are ever likelyto run your plane on the ground is about 40 mph and then only for a shorttime.6. I weighed my wheels and tires as they came from the cycle shop. Theyweighed 17 lbs. apiece. I was horrified until I started weighing regular6.00 x 6 aircraft wheels and found they weigh nearly as much. Don't worryabout it, if the wire wheels give the look you want. You might be carryinga 3 or 4 lb penalty. I haven't calculated the difference in weight of thetwo types of undercarriage, but I expect they are close to the same. Thesolid axle is heavy, but other than thet there is not much steel in thestraight axle gear, and the spruce struts probably weigh less than 2 lbstotal.Good luck,Jack -----Original Message-----

Original Posted By: Owen Davies
don't forget weldwood, which no one should have a quarrel with.do dnot archive----- Original Message -----

Original Posted By: Kip & Beth Gardner

Original Posted By: Kip & Beth Gardner

Original Posted By: "TWINBOOM"
Gene Rambo advised:> don't forget weldwood, which no one should have a quarrel with.Well, it was Weldwood resorcinol I was thinking of--the onlytrue structural glue I can get at the local hardware store. If youmean the usual Weldwood, the stuff like super contact cement,I don't even like it for basic woodworking. Maybe it's just me,but I've never gotten a bond with it that I could trust to hold upunder ordinary stresses, much less to hold me up under the stressesof flight.Of course, the same friend who loves polyurethane glues alsoloves Weldwood--not the resorcinol, the other stuff--and usedit to build significant parts of a HiMax. However, I notice thathe doesn't seem to fly it all that much.Owen Davies---Checked by AVG anti-virus system (http://www.grisoft.com).________________________________________________________________________________

Original Posted By: "DJ Vegh"
a good point about the J-3 gear being too tall to use with motor wirewheels.A question to those of you with motor wheels and straight axles.What is the distance between the ground and the bottom of the fuse directlyunder the axle centerline of the landing gear?I'd like to see how much it would differ from a J-3 gear with J-3 wheels.Also, I've seen some Husky's and J-3's that are configured for severe bushflying. They have huge balloon tires on them that make my off road FordRanger tires look pathetic. Do they increase the tail height by the sameamount to maintain a stock deck angle??I'm thinkning if I use 18" wheels instead of 21" wheels and use a tallertail wheel spring I could get away with the height problem. yes no??DJ VeghMesa, AZGN-1 Builderwww.raptoronline.comN74DV________________________________________________________________________________

Original Posted By: "Gary McNeel, Jr."
I did some more math on heights and angles.I found that a stock GN-1 with J-3 style wheels will sit at about an 11degree deck angle (ground to top longeron)If I put 18" motorcycle wheels the deck angle is about 13 degrees. a twodegree difference.I imported some pictures of straight axle motorcycle wheeled Piets into my3D program. Taking into acount the parralax and perspective of the photo Iwas able to determine that they were any where from 10 to 15 degreesdepending on the aircraft. Seems like deck angle isn't too critical aslong as it within the 10 to 15 degree range.BUT, I have never flown a tail dragger before so I have no experience inwhat all that means.Would there really be a drastic difference in landing style or handling if Iused an 18" motorcyle rim instead of a smaller wheel on a J-3 gear?help?!DJ VeghMesa, AZGN-1 Builderwww.raptoronline.comN74DV________________________________________________________________________________Date: Wed, 13 Mar 2002 10:20:07 -0600

Original Posted By: "Greg Cardinal"

Original Posted By: owner-pietenpol-list-server(at)matronics.com
DJ,You basically want the wing to stall just as the airplane reaches its3-point attitude. Most airfoils stall at an angle of attack of around 15degrees., so if you can keep the angle of attack at that or less, it shouldbe OK. Remember that the wing has an angle of incidence of 2 degrees (atleast on a Piet - I don't know what Grega uses), so if the longeron is at 11degrees , the angle of attack is 11+2=13 degrees.Many planes, including my Cessna 140, are not quite stalled at the 3 pointposition (Champs are that way as well). This was probably done as much asanything to provide better visibility over the nose on the ground. However,I learned to fly taildraggers in a J-3 Cub, which is fully stalled in the3-pont attitude, and find it frustrating to try to get a good three pointfully stalled landing in my 140. I usually end up landing tailwheel first,which then rapidly decreases the angle of attack and available lift and thewhole airplane comes down with a mighty "Whump" on the main gear.It is possible to make nice smooth landings in planes with low deck angles,but they can't be landed as slowly as they could if they had taller maingear.If the main gear is too tall, the opposite problem occurs, and the plane isalways landed on the main gear, and then the tailwheel will drop. If youtry to make a three point landing, the wing will stall before you get thetail low enough, and if your mains aren't already on the ground, it willfall out of the sky.Jack -----Original Message-----

Original Posted By: DJ Vegh
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Original Posted By: Kip & Beth Gardner

Original Posted By: "Christian Bobka"
Subject: Re: Pietenpol-List: motorcycle wheels on J-3 gearIn a message dated 3/12/02 9:54:01 PM Pacific Standard Time, aircamper(at)imagedv.com writes:> anyone sen motorcycle wire wheels on a J-3 style gear instead of straight> axle?> > I use 18 inch alum alloy rims (125cc dirt bike rear rims) with homemade 5 1/2 inch wide hubs on bronze oilite bushings on my split gear, A powered aircamper, with 1 1/2 inch dia axle. BHP built the Velie radial powered aircamper this way. That is where I got the idea. The tire size is on my plane 3.00 x 18. You could compare the gear geometry and determine the suitability. I our area, the spokes for building this type wheel are getting hard to find and the ones available are very expensive (about $200). On my second aircamper (which I built with Chuck Gantzer) we went back to the air wheel. The weight difference between these two sets of wheel assemblies is about three pounds per wheel, the spoke type being heavier. No brakes on either plane so can't help on those. Both airplanes handle the same on the ground to me, even though there is indeed a 5 ,or so, inch deck height difference.Doug Bryant ________________________________________________________________________________

Original Posted By: owner-pietenpol-list-server(at)matronics.com
I am back. Theanks for the support fellas.Maybe we can send twinboom down the hill from where he lives to investigatebuchanan rims and spokes first hand and report back on what they have.Doug?Chris-----Original Message-----

Original Posted By: "DJ Vegh"
DJ,Thats what type of setup that I have although I haven't flown it yet. Builtthe hubs myself, and used Harley spokes with 18" rims. I think mine lookgood. If you or anyone else is interested I can send infro. on all themat'ls.waltNX140DL----- Original Message -----

Original Posted By: "Jack Phillips"
Jack,One of the movie clips that I downlosded from Rich DeCosta's site shows aPiet with the split gear and big wheels doing what seems to be a nice 3point. Thats the setup that I have, but I haven't flown it yet.waltNX140DL----- Original Message -----

Original Posted By: Michael D Cuy

Original Posted By: Michael D Cuy

Original Posted By: owner-pietenpol-list-server(at)matronics.com
Gene, normally you are right and the airflow is not necessarily parallel tothe ground. However, assuming that the plane is making a smooth landing,it's downward velocity is almost zero and is negligible compared to itsforward speed. Also, in ground effect (which is defined as when the wing iswithin one wingspan length to the ground), there is no upward flow of theair just ahead of the wing's leading edge as there is when it is out ofground effect. These two thing s combined make the angle of the wing withrespect to the ground pretty close to its actual angle of attack.When you changed from 8.50 x 10 to 30 x 5 wheels, did the angle of theaircraft with respect to the ground change? How did the outside diametersof the two wheels compare? If that angle changed, I'm not surprised if theground handling changed.Jack -----Original Message-----

Original Posted By: Kip & Beth Gardner
Wait a minute . . . I gotta disagree here. First of all, in the math belowyou cannot figure the angle of attack like that because you are assumingthat the relative airflow remains constant and parallel with the groundwhich is not so.A tailwheel airplane lands much, much better three-point with smallerdiameter wheels rather than larger. I used to have 8.50x10 low pressurewheels on my Travel Air, but a couple of years ago I installed the large30x5 disc wheels. Went from a complete pussycat to land into a thing with amind of its own. A lot of very experienced antiquers have scratched theirheads over an explanation, because not many people have had a lot of hourson an airplane with one size wheel (1100) and then changed that airplane tothe disc wheels so that a direct comparison could be made. I still have notheard a thorough explanation I liked.Gene(yes I was referring to the Weldwood plastic resin glue)I do not think there has been a single subject that has been discussed onthis list more than wire wheels, how to build them, how to spoke them, howbig, etc., etc. Some of you might want to look in the archives.----- Original Message -----

Original Posted By: "John McNarry"
Subject: Re: Pietenpol-List: motorcycle wheels on J-3 gearIn a message dated 03/13/2002 6:46:00 PM Central Standard Time, llneal2(at)earthlink.net writes:>Larry..Every sidecar wire wheel I have seen is made like the aviation wire wheels of the twenties which were designed specifically to take side loads. Next time you see one, note that the spokes are not attached to the rim on the centerline as are motorcycle wheels, but rather are positioned outboard of centerline and have wider hubs. On the old Harleys (like my old 1935 VL-74 with sidecar), the main wheels were conventional but the sidecar wheel, which can be subjected to severe side loads on left turns was built as mentioned. My 2 cents. Don ________________________________________________________________________________

Original Posted By: owner-pietenpol-list-server(at)matronics.com
See "Custom Planes" April 2002 Nice article on Piets. The featured Piet ison tall wheels and Cub style gear. I talked to a Corvair Powered Piet driverat Brodhead. (forget the year and his name, Silver/Blk with turned enginecowling and cast "Aircamper" valve covers) He had the misfortune of a forcedlanding in a bean feild on that Saturday. He re-started and took off fromthe field. I wonder if that would have been possible with small wheels orwith tall wheels and a straight axle. We debated the issue at length aroundthe campfire and didn't come to a conclusionother than it is mostly a matter of taste.J Mc-----Original Message-----

Original Posted By: clif

Original Posted By: clif

Original Posted By: Larry Neal

Original Posted By: Larry Neal

Original Posted By:
airplane wire wheel spokes are attached to the centerline of the rim.----- Original Message -----

Original Posted By: John McNarry
tall wheels if the ground was firm but bumpy . . . small, fat tires if theground was soft. Big wheels are made for rolling over uneven ground but arenot wirth a d*** on soft ground.----- Original Message -----

Original Posted By: Gene Rambo
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Original Posted By: Michael D Cuy

Original Posted By: "Michael D Cuy"
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Original Posted By: owner-pietenpol-list-server(at)matronics.com
Not on a curtiss jenny or most of the planes at Rhinebeck or the AF Museumthat have original wheels.Chris b-----Original Message-----

Original Posted By: "Gary McNeel, Jr."

Original Posted By: Christian Bobka
The wheels you are talking about on those kind of aircraft are "clincher"type wheels which predate the 20's, not likely to be found on any Piet.----- Original Message -----

Original Posted By: "Gene Rambo"
Subject: Re: Pietenpol-List: motorcycle wheels on J-3 gearIn a message dated 03/18/2002 4:28:30 PM Central Standard Time, rambog(at)erols.com writes: Not on a curtiss jenny or most of the planes at Rhinebeck or the AF Museum > that have original wheels. > > Chris b >>OK Chris, I stand corrected. Guess I ought to let the guys at the Ft. Rucker Museum know that they've got the wrong wheels on their Jenny. Don________________________________________________________________________________