Results 1 to 33 of 33

Thread: J-3 on 29" ABWs

  1. #1
    stearmann4's Avatar
    Join Date
    Aug 2006
    Location
    Tenino, WA
    Posts
    226
    Post Thanks / Like

    J-3 on 29" ABWs

    Guys,

    After of convincing myself I don't need them, I think I really need 29" Airstreaks on my J-3. Most notably because I came across an almost new set that a friend had on a 65hp Champ and didn't;t like em'. I currently have (legally) mounted 8.50 AirTracs on Cleveland wheels/brakes with DA safety cables installed. My only concern is will the extra weight place an additional stress on my stock J-3 gear? I have a C-85 Stroker with a 74" Sensenich metal climb prop, so power shouldn't be an issue.

    I'm getting the STC paperwork and will obviously have to make an updated W & B, anyone have ay lessons learned, or what the weight increases will be between the 8.50s and the 29s? I tried to search the archives, but after almost 2 hours I figured it would just be faster to ask again.

    Mike-

  2. #2
    cubdriver2's Avatar
    Join Date
    Apr 2003
    Location
    upstate NY
    Posts
    10,587
    Post Thanks / Like
    I've been running 31s all summer without any problems. Adds about 40' to the takeoff roll.

    Glenn

  3. #3
    tophand's Avatar
    Join Date
    Sep 2010
    Location
    Northwest South Dakota
    Posts
    275
    Post Thanks / Like
    I've been running 29s for a few years now and I'd hate to go back. I put SC gear legs on with a doubler inside the axle. Overkill....maybe. One thing I have learned. Resist the temptation to take the covering off the gear legs on a J3. It is a bigger performance hit than the tires themselves. I'm going to cover them this winter.

    Good luck ......Mike
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	IMG_0629.jpg 
Views:	215 
Size:	916.6 KB 
ID:	17715  
    Last edited by tophand; 11-11-2014 at 10:49 AM.

  4. #4
    stearmann4's Avatar
    Join Date
    Aug 2006
    Location
    Tenino, WA
    Posts
    226
    Post Thanks / Like
    Quote Originally Posted by tophand View Post
    Resist the temptation to take the covering off the gear legs on a J3. It is a bigger performance hit than the tires themselves. I'm going to cover them this winter.
    Good to know, cuz' that was the first thing I was going to do.

    Mike-

  5. #5
    tophand's Avatar
    Join Date
    Sep 2010
    Location
    Northwest South Dakota
    Posts
    275
    Post Thanks / Like
    I actually like the looks of the open gear legs a bit more. I've been flying with them open for about a year now and maybe it just feels slower. I've been trying to figure out a removable cover.

    I guess that I should really qualify that to say that it's only really noticeable on long cross country flights. I'm about a 100 miles from anywhere out here so I spend quite a bit of time looking out the window. Flying around close you don't notice it so much.

    .....Mike
    Last edited by tophand; 11-11-2014 at 12:16 PM.

  6. #6

    Join Date
    Nov 2004
    Location
    Hoonah, Alaska
    Posts
    125
    Post Thanks / Like
    if you would go on a diet, you wouldn't notice the weight of the tires as much there chubby!

  7. #7
    tophand's Avatar
    Join Date
    Sep 2010
    Location
    Northwest South Dakota
    Posts
    275
    Post Thanks / Like
    Jeez with friends like you who need enemies. Was it you that left the door open when you came down???

    .....Mike

    Finally got released Sat. (from the tanker base smart %$#)

  8. #8
    mvivion's Avatar
    Join Date
    Jun 2003
    Location
    Bozeman,MT
    Posts
    11,449
    Post Thanks / Like
    Quote Originally Posted by stearmann4 View Post
    Guys,

    My only concern is will the extra weight place an additional stress on my stock J-3 gear?
    Mike-
    The BW STC requires "heavy duty gear". Not sure what that means, but.....

    MTV

  9. #9
    WWhunter's Avatar
    Join Date
    Aug 2003
    Location
    Laporte, Minnesota and the white sandy beaches of NW Florida
    Posts
    1,519
    Post Thanks / Like
    MTV, Does it require heavy duty gear or is it heavy duty brakes? I am currently flying an experimental on 29" bushwheels but I seem to recall the STC stating heavy duty brakes when I had the 26" bushwheels installed on the Champ I sold. You have my curiosity up as I don't recall the requiement for heavy duty gear, but that may have been airplane specific also.
    As a side discussion, I sold the 26'' tires to upgrade to 29's and after doing so I wish I would have just kept the 26's. They were all I needed for the spots I was landing. Granted, the 29's look better but they are not needed for the majority of these small light planes. Opinion of course.

  10. #10
    tophand's Avatar
    Join Date
    Sep 2010
    Location
    Northwest South Dakota
    Posts
    275
    Post Thanks / Like
    MTV.. I remember seeing that somewhere but I just read through the STC and the installation instructions and it didn't say anything about HD gear. It was just a quick once over so I may have missed something in the instructions. The STC however has no mention of the gear or brakes at all. There are limitation notes called out on the STC but I don't have those right now.

    .......Mike

  11. #11
    mvivion's Avatar
    Join Date
    Jun 2003
    Location
    Bozeman,MT
    Posts
    11,449
    Post Thanks / Like
    From page 10 of 10 of the FAA approved model list for installation of Alaskan Bushwheel, inc Tundra Tires:

    1. Must have heavy duty brakes

    2. Must have PA-18 type gear or other Heavy Duty Type gear installed under separate approval.

    3. Seaplane models are eligible when converted to wheel gear under separate approval.

    Notes under the J-3/PA-11 approval state that Notes 1, 2, and 3 apply to these aircraft.

    MTV

  12. #12

    Join Date
    Sep 2003
    Posts
    7,399
    Post Thanks / Like
    I am seeing J-3s come in at 850 lbs empty with standard gear and not much else in the way of heavy stuff. What do they weigh when you hang heavy brakes, gear, the obligatory safety cables, and really big tires on?

    Yes, I know a J-3 can perform at 1400 lbs, but insurance doesn't work at those weights.

  13. #13
    mvivion's Avatar
    Join Date
    Jun 2003
    Location
    Bozeman,MT
    Posts
    11,449
    Post Thanks / Like
    Bob,

    My 11 weighs 832 with Clevelands and 26 inch Streaks. That's a recent weight on certified scales.

    MTV

  14. #14
    Steve Pierce's Avatar
    Join Date
    Mar 2002
    Location
    Graham, TX
    Posts
    20,724
    Post Thanks / Like
    Late J3 gear is the same part number as Super Cub gear. 90 hp J3 on 29" Airstreaks would be illegal if the FAA knew how much fun it is.
    Steve Pierce

    Everybody is ignorant, only on different subjects.
    Will Rogers

  15. #15
    tophand's Avatar
    Join Date
    Sep 2010
    Location
    Northwest South Dakota
    Posts
    275
    Post Thanks / Like
    751# with 29" Airstreaks and Clevelands and the obligatory cables. "No springs honest weight"

    ......Mike

  16. #16
    BES's Avatar
    Join Date
    Jun 2002
    Location
    Esbjerg, Denmark
    Posts
    449
    Post Thanks / Like
    Quote Originally Posted by tophand View Post
    Resist the temptation to take the covering off the gear legs on a J3. It is a bigger performance hit than the tires themselves. I'm going to cover them this winter.

    Good luck ......Mike
    How much of a performance hit is it, really? I left the gear legs of my -12 uncovered and like it that way. Do you really mean there would be a noticeable difference in cruise performance if the gear legs were covered??

  17. #17
    courierguy's Avatar
    Join Date
    Dec 2004
    Location
    Inkom, Idaho
    Posts
    1,851
    Post Thanks / Like
    Of course leaving the gear legs uncovered won't effect your cruise speed, you'll just need more power to hit that same cruise speed.

  18. #18
    tophand's Avatar
    Join Date
    Sep 2010
    Location
    Northwest South Dakota
    Posts
    275
    Post Thanks / Like
    Quote Originally Posted by courierguy View Post
    Of course leaving the gear legs uncovered won't effect your cruise speed, you'll just need more power to hit that same cruise speed.
    This hits the nail square on the head.

    I too have a stroker, so I have a bit of extra power. Enough to still cruise at 90 if I keep it at full throttle. But that's not very efficient. My plane has a "notch" where it like to run. That's around 2350. Before putting on the uncovered gear legs it would cruise at 90 indicated at that rpm. Now it's between 80-85mph at the same rpm. I just thought it might be useful to let Stearmann4 know before he cut the fabric off. As I said before I like the uncovered gear too, that's why I left it off. The performance hit is enough my J3 to make me seriously consider recovering the gear.
    Hoonahcub tells me I should just go SC and quit fooling around. He is probably right I just can't let him know that he is.

    ......Mike

  19. #19
    soyAnarchisto's Avatar
    Join Date
    Aug 2012
    Location
    Boulder, CO
    Posts
    579
    Post Thanks / Like
    I got 29's six months ago. Glad I did. 811lbs w abw, clevelands, wag aero wing tanks, Scott 3200 tw, microair xpondr and a 406 elt.

    Prolly now more than 10lbs diff than 8.5s which are pretty heavy - and illegal too. You are only supposed to go up to 8.0s w clevelands
    Where the hell is soyAnarchisto? Spot:

    http://share.findmespot.com/shared/f...SWNtWd0Trffc0F

  20. #20

    Join Date
    Dec 2006
    Location
    Hot Springs, SD
    Posts
    370
    Post Thanks / Like
    The 29" ABW airstreaks weigh 26lbs and the 26" weigh 19 if I remember correctly.

  21. #21

    Join Date
    Mar 2011
    Posts
    58
    Post Thanks / Like
    Have been using 24x11x4 and like them, need to beef up my brakes, any suggestions? Have a spare set for sale if anyone interested. Also am in process of rebuilding my 85 as a stroker, any recommendations? Only one I have priced so far is Don's dream machines.

  22. #22
    cubdriver2's Avatar
    Join Date
    Apr 2003
    Location
    upstate NY
    Posts
    10,587
    Post Thanks / Like
    Quote Originally Posted by duckhunter10 View Post
    Have been using 24x11x4 and like them, need to beef up my brakes, any suggestions? Have a spare set for sale if anyone interested. Also am in process of rebuilding my 85 as a stroker, any recommendations? Only one I have priced so far is Don's dream machines.
    He's what I do, I wrote this for j3.com, It works if you do it right.

    Re: Goodyear brakes, hints and tips to use them till they don't work and then some
    Bruce, jack the plane up so that the tire is free to turn, loosen the bleeder and pump like hell till the tire won't turn and close the bleeder with the tire locked, now open the bleeder a little till the tire will just move and then close the bleeder. What your trying to do is remove the air gap between the pads and the drum. It helps if you do this with help but I do it all the time alone. Caution, you need to hold and support the tube coming out of the expander tube with one hand while you push the nipple of the squirt can against it or you might damage the expander tube, you need to pump as fast as you can to keep up with whats leaking out, it helps to use a t-shirt rag as a gasket between the nipple and the bleeder and pump the 5606 thru the rag. You should have great brakes after this so either screw your tires on or run them at 20psi. I like them at 10psi and screwed.

    I've got over 1500hrs on expander tube brakes and 25" Goodyears. I can do a run up to 2400rpm before they start to roll, on wet grass they will slide.


    Click on the photo and it will start a video of a j3 with stock brakes and 25 Goodyears. Had a cruise prop and only staticed at 2350




    I haven't added fluid to the master cylinder in years. I don't even look I fill from the bottom.

    Glenn
    Last edited by cubdriver2; 11-13-2014 at 12:56 PM.

  23. #23
    mvivion's Avatar
    Join Date
    Jun 2003
    Location
    Bozeman,MT
    Posts
    11,449
    Post Thanks / Like
    Quote Originally Posted by Steve Pierce View Post
    Late J3 gear is the same part number as Super Cub gear.
    Good to know, thanks Steve.

    MTV

  24. #24
    mvivion's Avatar
    Join Date
    Jun 2003
    Location
    Bozeman,MT
    Posts
    11,449
    Post Thanks / Like
    Quote Originally Posted by cubdriver2 View Post
    He's what I do, I wrote this for j3.com, It works if you do it right.

    Re: Goodyear brakes, hints and tips to use them till they don't work and then some
    Glenn
    Good info, Glenn, but what do you do with GoodRICH brakes?

    MTV

  25. #25
    Steve Pierce's Avatar
    Join Date
    Mar 2002
    Location
    Graham, TX
    Posts
    20,724
    Post Thanks / Like
    Steve Pierce

    Everybody is ignorant, only on different subjects.
    Will Rogers

  26. #26

    Join Date
    Nov 2014
    Location
    Cleveland, OH
    Posts
    3
    Post Thanks / Like
    New member, just purchased a 1946 J-3 project. I would like to put big tires on eventually. Were do I find the STC and what combination of brakes would be sugested? It looks like there is disagrement on the gear legs required. Joe B

  27. #27
    tophand's Avatar
    Join Date
    Sep 2010
    Location
    Northwest South Dakota
    Posts
    275
    Post Thanks / Like
    No disagreement... What MTV posted in #8 and #11 is correct. Also read Steve Pierce's posts #14 and # 25. You may be lucky and already have the heavier gear.

    ......Mike

  28. #28

    Join Date
    Nov 2014
    Location
    Cleveland, OH
    Posts
    3
    Post Thanks / Like
    I already indend to replace the original brakes. What would be considered heavy duty? Joe B

  29. #29
    tophand's Avatar
    Join Date
    Sep 2010
    Location
    Northwest South Dakota
    Posts
    275
    Post Thanks / Like
    I think most go with the Cleveland kits. You can get those from Airframes Alaska along with the tires. Grove Brakes is an option too.

    .....Mike

  30. #30
    mvivion's Avatar
    Join Date
    Jun 2003
    Location
    Bozeman,MT
    Posts
    11,449
    Post Thanks / Like
    Aren't all the "legal" Grove brakes for the J-3 four inch wheels? That'll definitely limit the choices of tires....

    MTV

  31. #31
    tophand's Avatar
    Join Date
    Sep 2010
    Location
    Northwest South Dakota
    Posts
    275
    Post Thanks / Like
    Quote Originally Posted by mvivion View Post
    Aren't all the "legal" Grove brakes for the J-3 four inch wheels? That'll definitely limit the choices of tires....

    MTV
    Yep you are correct..... What was I thinkin. Thanks....Mike

    .......Mike

  32. #32
    cubdriver2's Avatar
    Join Date
    Apr 2003
    Location
    upstate NY
    Posts
    10,587
    Post Thanks / Like
    Quote Originally Posted by mvivion View Post
    Good info, Glenn, but what do you do with GoodRICH brakes?

    MTV
    Cub shorthand. Goodrich/Goodyear

    Glenn

  33. #33
    cubdriver2's Avatar
    Join Date
    Apr 2003
    Location
    upstate NY
    Posts
    10,587
    Post Thanks / Like
    Quote Originally Posted by moving2time View Post
    I already indend to replace the original brakes. What would be considered heavy duty? Joe B
    The original brakes if properly pumped up are all you need for 25 x 11 x 4

    Glenn

Similar Threads

  1. Replies: 1
    Last Post: 10-13-2014, 06:06 PM
  2. life for me on the ground "allmost as fun as flying"NOT"
    By koontzcollc in forum Video Vault
    Replies: 7
    Last Post: 02-25-2014, 02:33 PM
  3. Are "Certified Aircraft" safer than "Experime
    By cubflier in forum Cafe Supercub
    Replies: 19
    Last Post: 11-06-2006, 02:00 PM
  4. Putting the "Thanks" back in "Thanksgiving
    By SJ in forum Cafe Supercub
    Replies: 16
    Last Post: 11-27-2003, 05:06 PM

Tags for this Thread

Bookmarks

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •