Page 2 of 2 FirstFirst 12
Results 41 to 78 of 78

Thread: 26" tire choice

  1. #41
    Crash, Jr.'s Avatar
    Join Date
    May 2015
    Location
    Anchorage, AK
    Posts
    265
    Post Thanks / Like
    Anybody have drag/speed loss numbers on 850x6 and 26" tires? All this talk of the difference between the Desser 850 tundra and the 26 Goodyear has me curious what sort of difference in speed would be realized between those two.

  2. #42

    Join Date
    Sep 2003
    Posts
    7,272
    Post Thanks / Like
    On the crosswinds: when you touch down, there are two things trying to turn you in to the wind. One is the drag on the touchdown wheel, and the other is the wind blowing on the aft end of the aircraft. At touchdown you have only rudder and differential aileron drag counteracting those two forces. Your rudder and aileron authority, compared to the wind pressure and wheel drag, are all you’ve got.

    At max control input, increasing drag on that wheel means decreasing the crosswind.

    If you want to know how much extra drag a 26” Goodyear is, try to move a Cub with those tires up a slight incline with a towbar.

    And sure - once both mains are on the ground the drag is now offset. How many Cub pilots land in a 20 knot crosswind on both mains?

    thanks for all the info - I think Steve will opt for Goodyears and call Steve in Carefree. We picked up a UPF-7 in Carefree a while back - great airplane!
    Likes RVBottomly liked this post

  3. #43
    Gordon Misch's Avatar
    Join Date
    Dec 2003
    Location
    Toledo, Wa (KTDO)
    Posts
    3,701
    Post Thanks / Like
    Anybody have drag/speed loss numbers on 850x6 and 26" tires?
    I've used both of those, and 31s on my -12. I'd say the speed difference between 8.50 Dessers and 31s is roughly 5 mph, with the 26s falling in the middle.
    Gordon

    N4328M KTDO
    My SPOT: tinyurl.com/N4328M (case sensitive)

  4. #44
    Gordon Misch's Avatar
    Join Date
    Dec 2003
    Location
    Toledo, Wa (KTDO)
    Posts
    3,701
    Post Thanks / Like
    Bob, pump the tires up and they all roll just fine. I haven't noticed any discernable difference between 8.50s, BW 26s and BW 31s in crosswinds. I'd bet the GY 26s will feel a lot like 8.50s; unless they're soft, of course.
    Gordon

    N4328M KTDO
    My SPOT: tinyurl.com/N4328M (case sensitive)
    Likes Hardtailjohn liked this post

  5. #45

    Join Date
    Aug 2017
    Posts
    37
    Post Thanks / Like
    Quote Originally Posted by mam90 View Post
    Attachment 51865 Attachment 51866

    These are the best pics I have to show the size of the Desser 8:50’s. 3 years, about 350 hours 50/50 pavement and other. Holding up well so far.
    Mam90 is that a 18-150? Really nice!


    Sent from my iPhone using SuperCub.Org mobile app

  6. #46

    Join Date
    Sep 2002
    Location
    Southern NH
    Posts
    712
    Post Thanks / Like
    Thanks. No, it’s a J-3 with most of Atlee’s mods.
    Thanks Bowie thanked for this post

  7. #47

    Join Date
    Aug 2017
    Posts
    37
    Post Thanks / Like
    Quote Originally Posted by mam90 View Post
    Thanks. No, it’s a J-3 with most of Atlee’s mods.
    Wow! Can you tell me some of the mods? Electricity? What is useful load? I had a J3 C 90 and loved it. Just not the hand propping.



    Sent from my iPhone using SuperCub.Org mobile app

  8. #48

    Join Date
    Sep 2002
    Location
    Southern NH
    Posts
    712
    Post Thanks / Like
    I’ll send you a PM later today so that we don’t hijack this thread..

  9. #49

    Join Date
    Sep 2003
    Posts
    7,272
    Post Thanks / Like
    Gordon - so spin-up inertia doesn't affect initial adverse drag on touchdown?

    Are you routinely practicing in 20 kt direct crosswinds?

    Granted - the hard 26s do handle crosswinds almost as well as an 8:50, but have you tried 29s in a 20 knot direct xwind?

  10. #50

    Join Date
    Sep 2003
    Posts
    7,272
    Post Thanks / Like
    Since I started it, I do not mind hijacking - as always around here, I got the info I needed and then some. You guys are great.
    Likes Dave Calkins liked this post

  11. #51
    Crash, Jr.'s Avatar
    Join Date
    May 2015
    Location
    Anchorage, AK
    Posts
    265
    Post Thanks / Like
    If I had a 20knot direct crosswind I'd probably just land on a taxiway turnoff. Landing would only be about 75 foot with that much wind!

    Plus good lord, I'd hate to be up if it was that gusty. In a J3 you'd be bouncing around inside the cabin like a rubber ball.
    Likes JeffP, supercrow liked this post

  12. #52
    mvivion's Avatar
    Join Date
    Jun 2003
    Location
    Bozeman,MT
    Posts
    11,110
    Post Thanks / Like
    Quote Originally Posted by bob turner View Post
    And sure - once both mains are on the ground the drag is now offset. How many Cub pilots land in a 20 knot crosswind on both mains?

    thanks for all the info - I think Steve will opt for Goodyears and call Steve in Carefree. We picked up a UPF-7 in Carefree a while back - great airplane!
    Bob, who said anything about landing both tires simultaneously in a crosswind? What you’re describing is initial spool up of the tire on the upwind side. That’s a very momentary force, and is easily overcome by proper control application. Once that Bushwheel is down, and rolling, it provides much less opportunity to skid. Plane just runs along on that tire till it’s time to put down the other. The force to keep a larger tire spinning once it’s spun up is easily overcome with minimal control forces.

    MTV

  13. #53

    Join Date
    Oct 2012
    Location
    Wolf Lake, AK
    Posts
    5,621
    Post Thanks / Like
    Mounted 35s weigh 68# each. Talk about spin-up factor, but even at that it's no big deal. 26" Goodyears are a total non-event. In a crosswind tall tires add to the excitement. More height, more excitement. And more AOA. Plus with Bushwheels you get all the sidewall flex, too. Smaller, harder tires are better in unfavorable winds.

  14. #54
    mvivion's Avatar
    Join Date
    Jun 2003
    Location
    Bozeman,MT
    Posts
    11,110
    Post Thanks / Like
    I dunno, I’ve landed in winds I couldn’t safely taxi in, while running “oversized” tires (not 35 inch Bushwheels). Not fun, but mostly it’s an exercise in reducing the crosswind component, whether you’re running big or small tires.....then figuring out what to do next......like find some wing walkers.

    Just how much wind are you guys tackling, anyway?

    MTV

  15. #55
    BC12D-4-85's Avatar
    Join Date
    Feb 2016
    Location
    Fairbanks, AK.
    Posts
    2,525
    Post Thanks / Like
    Enter the Newbie: Late Fall 1975 Merrill Field Anchorage in a just bought PA-18 (N7777D) with checkout pilot in back. T&G on old style 25x11x4's first left black marks on the runway. Screeech screech! I was informed to tap them to roll 'em up some then set down a few feet later to save the rubber. Still works.

    Gary

  16. #56

    Join Date
    Oct 2012
    Location
    Wolf Lake, AK
    Posts
    5,621
    Post Thanks / Like
    You haven't had fun taxing in the wind until you've flown a slat wing on 6" ext gear and 35s. But I'm just a toddler in dog years when it comes to my big wing Cub.

    Talking personal wind limits will be a waste of time. Guys will be wagging Johnsons before you know it. I'll pass.

  17. #57

    Join Date
    Sep 2002
    Location
    Southern NH
    Posts
    712
    Post Thanks / Like
    Quote Originally Posted by BC12D-4-85 View Post
    Enter the Newbie: Late Fall 1975 Merrill Field Anchorage in a just bought PA-18 (N7777D) with checkout pilot in back. T&G on old style 25x11x4's first left black marks on the runway. Screeech screech! I was informed to tap them to roll 'em up some then set down a few feet later to save the rubber. Still works.

    Gary
    I recognize that number, I was working at Pats Flying Service about that time... were the 25x11x4’s the ones that had the springs in them that everybody pulled out?

  18. #58
    BC12D-4-85's Avatar
    Join Date
    Feb 2016
    Location
    Fairbanks, AK.
    Posts
    2,525
    Post Thanks / Like
    I bought it from Lou Armbruster (also had a Heliocourier) at Merrill for $15K. New factory engine and 4 yrs on rebuild. Sheep hunter special.

    No metal staples on the 25's...the ice grip ~31-36" tires had them and they took several six packs to remove. Today many of those tires are still airworthy and flyable with little weather deterioration. Tubed with 8:50x6" tubes and held to the 4" rims with fiberglass or metal adapters that adapt the lugged rims to the smooth wheels. Plus we screwed through the wheels>adapters>tires to allow less air pressure.

    Gary
    Likes Hardtailjohn liked this post

  19. #59

    Join Date
    Sep 2002
    Location
    Southern NH
    Posts
    712
    Post Thanks / Like
    Ah yes.... I spent many an hour pulling those buggers out, and I remember the screws into the tires. Good times.

  20. #60
    BC12D-4-85's Avatar
    Join Date
    Feb 2016
    Location
    Fairbanks, AK.
    Posts
    2,525
    Post Thanks / Like
    Jim Helmericks from the Colville River delta was the first I came across that claimed he could land anywhere he wanted on the big 36". It took a quick look to see why and that was before fat tailwheels. Now look at what's available from Airframes. It's been quite an evolution for the better.

    Gary
    Likes mam90 liked this post

  21. #61
    Gordon Misch's Avatar
    Join Date
    Dec 2003
    Location
    Toledo, Wa (KTDO)
    Posts
    3,701
    Post Thanks / Like
    Quote Originally Posted by bob turner View Post
    Gordon - so spin-up inertia doesn't affect initial adverse drag on touchdown?

    Are you routinely practicing in 20 kt direct crosswinds?

    Granted - the hard 26s do handle crosswinds almost as well as an 8:50, but have you tried 29s in a 20 knot direct xwind?
    Well Bob, you do know how to get me started, don't you?

    So - re "routine" 20 kt crosswinds, no. Routine turbulent teens crosswinds, yep. Teens gusting 20s crosswinds, sometimes. Occasional (rare) 30's cross, yep. Wind more or less down the rwy? Rare! My understanding is that when KTDO was built during WW2, it was deliberately oriented for military crosswind practice.

    Re the tires - I switch around between 26 bushwheels, 31 bushwheels, and 8.50s. Never 29s. I haven't noticed a difference in crosswind handling between those tires. But never really looked for a difference either.

    Re spinup, sure it's there, but to my senses it's negligible - I simply don't feel it. For fun, go do some one-wheel landings with no crosswind, then with the new tires do it again and see what it feels like to you. Granted, the J3 is lighter than the -12, so any difference between tires would be a little more pronounced in the J3.

    If I get ambitious, maybe I'll do some comparative calcs and email 'em to you. Just for grins and giggles. I'd need your operating weight and CG as measured from the axles.
    Gordon

    N4328M KTDO
    My SPOT: tinyurl.com/N4328M (case sensitive)
    Thanks hangarmonkey thanked for this post

  22. #62
    mvivion's Avatar
    Join Date
    Jun 2003
    Location
    Bozeman,MT
    Posts
    11,110
    Post Thanks / Like
    Quote Originally Posted by stewartb View Post
    Talking personal wind limits will be a waste of time. Guys will be wagging Johnsons before you know it. I'll pass.
    It was a rhetorical question, Stewart, not a challenge,

    MTV

  23. #63

    Join Date
    Sep 2003
    Posts
    7,272
    Post Thanks / Like
    Gordon has me beat - at 20 knots I am maxed out. No more rudder, no more aileron, and once scraped a wing. Easy fix; a quarter-inch fabric patch.

    I seek them - but only where I can walk home. We will have 26, on an otherwise stock J3 - and just in time for winter crosswind practice.

    Should I tell you about my very experienced friend with thousands of Cub landings, and 31s? Nah . . .

  24. #64
    Gordon Misch's Avatar
    Join Date
    Dec 2003
    Location
    Toledo, Wa (KTDO)
    Posts
    3,701
    Post Thanks / Like
    Well Bob, you can bet I operate diagonal to the runway when it starts feeling marginal.
    Gordon

    N4328M KTDO
    My SPOT: tinyurl.com/N4328M (case sensitive)

  25. #65
    TurboBeaver's Avatar
    Join Date
    Jun 2009
    Location
    Northern Maine
    Posts
    818
    Post Thanks / Like
    When it comes to scuffin your tires before you landed on asphalt: the old rock hard 36" Goodyear Airwheels were the worst tire
    I ever flew on a Cub, at 61/62 lbs respectfully , wheel landings were "spooky"
    Without scuffin em first to get all that weight & moment turning! Once you had em spooled up they were ok. Those tires were extremely stiff, and very hard on the Airframe, and they really gave the bungees a workout! With 6 screws on each wheel! I still cut off some valve stems! Once at King Salmon in front of a Mark Air 737 flight that had to circle, because I freaked out because the arestor cable was 'up for the fighters, and I wasnt sure if I could roll over it or not? Georgie Tibbets to the rescue! We got her off the runway, found a tube at Penn Air
    And got going again. In big crosswinds I like to exceed diagonal: and land straight across into a taxiway..........

    Sent from my moto e5 go using SuperCub.Org mobile app

  26. #66
    skywagon8a's Avatar
    Join Date
    Mar 2008
    Location
    SE Mass
    Posts
    10,654
    Post Thanks / Like
    Quote Originally Posted by bob turner View Post
    Gordon - so spin-up inertia doesn't affect initial adverse drag on touchdown?
    Quote Originally Posted by Gordon Misch View Post
    Well Bob, you do know how to get me started, don't you?

    Re spinup, sure it's there, but to my senses it's negligible - I simply don't feel it.

    If I get ambitious, maybe I'll do some comparative calcs and email 'em to you. Just for grins and giggles. I'd need your operating weight and CG as measured from the axles.
    You two have my attention.
    It seems to me the tires with the larger diameter would have less spin up resistance due to the larger radius providing more leverage. This assuming equal air pressures on each. IF the tires are being run with low pressure due to their being used in the "rough", then I would expect more spin up resistance. Enough more to cause an accident if landing on pavement.

    Long ago there was a 180/185 accident at ANC when it landed on the hard with some Schneider racing slicks. They were set to a low pressure for bush landings, then when landed on the pavement they stuck like glue with the same result as landing an amphib in the water with the gear down.

    Why would you land in a 20 knot crosswind with a Cub when you can easily turn and land cross runway? It wouldn't require a very wide runway in those winds. Granted, if you're using a one track road you won't have that option.
    N1PA

  27. #67

    Join Date
    Oct 2012
    Location
    Wolf Lake, AK
    Posts
    5,621
    Post Thanks / Like
    Why would you land in a 20 knot crosswind with a Cub when you can easily turn and land cross runway? It wouldn't require a very wide runway in those winds. Granted, if you're using a one track road you won't have that option.
    Narrow. Lined by tall trees. Vicious turbulence. Add a slick or loose surface for even more excitement. The same problems await you when taking off. We can make several attempts to land. We usually only get one go at departure. Judgement of conditions from the air looking down is different than from the ground looking up.

  28. #68
    Crash, Jr.'s Avatar
    Join Date
    May 2015
    Location
    Anchorage, AK
    Posts
    265
    Post Thanks / Like
    Quote Originally Posted by stewartb View Post
    Narrow. Lined by tall trees. Vicious turbulence. Add a slick or loose surface for even more excitement. The same problems await you when taking off. We can make several attempts to land. We usually only get one go at departure. Judgement of conditions from the air looking down is different than from the ground looking up.
    And what airport in the Anchorage area is this?

  29. #69

    Join Date
    Oct 2012
    Location
    Wolf Lake, AK
    Posts
    5,621
    Post Thanks / Like
    Are we limited to airports? Fly around the valley a bit and look at 90% of the private strips. At Wolf Lake the prevailing wind is 45* from the primary and crosswind runways. And I've observed some seriously sporty landings lately. And a few seriously sporty go-arounds that evolved into go-aways. Heck, fly in and out of the old Creek strip for a few years. That one's a real charmer when the wind's blowing 40 down the Yentna.

  30. #70
    Crash, Jr.'s Avatar
    Join Date
    May 2015
    Location
    Anchorage, AK
    Posts
    265
    Post Thanks / Like
    Just yankin your chain. The original comment was about crosswinds and paved runways though so off-airport isn't quite what the group was talking about.

    I get your point though but I've never had an issue once below the treetops with crosswinds. It can be a little blustery but once you drop below the wind break it's a non-event at least when you're talking about narrow runways lined by trees.

    To be honest though I just don't go up when it's that windy. What's the point of flying if it's not going to be fun and my ground speed has a good chance of being close to zero?
    Likes stewartb liked this post

  31. #71
    Gordon Misch's Avatar
    Join Date
    Dec 2003
    Location
    Toledo, Wa (KTDO)
    Posts
    3,701
    Post Thanks / Like
    It seems to me the tires with the larger diameter would have less spin up resistance due to the larger radius providing more leverage.
    Pete, the more leverage part is correct, and of course is directly proportional to the tire diameter. However the resistance to spin up, "moment of inertia", which is the rotational equivalent of mass, is approximately proportional to the square of the diameter. That makes the spin up effort ("rotational impulse") roughly proportional to the tire diameter. I say "approximately" and "roughly" because of a tire's weird shape and mass distribution as compared to a uniform, solid disc.
    Gordon

    N4328M KTDO
    My SPOT: tinyurl.com/N4328M (case sensitive)
    Likes skywagon8a, TurboBeaver liked this post

  32. #72
    Alex Clark's Avatar
    Join Date
    Feb 2004
    Location
    Life Long Alaskan
    Posts
    3,184
    Post Thanks / Like
    Then there is also the temporary tire shape distortion and often out of balance natural of large soft tires hitting the pavement.
    We have videoed the tires a few times on landings and it is amazing how they flex all over when they are in a low pressure state.
    Float and Tailwheel CFI,
    Dragonfly Aero
    Homer, Alaska
    dragonfly@alaska.net

    http://www.floatplanealaska.com

    or http://www.dragonflyaero.net
    Likes TurboBeaver liked this post

  33. #73

    Join Date
    Sep 2003
    Posts
    7,272
    Post Thanks / Like
    Remember, the original question was big tires for 99.9% pavement operations (at large tower-controlled airports).

    Going out and seeking crosswinds is one of my great joys. It is risky, but for me, fun. Going out and landing on places that are way far away from civilization and rough enough to require big tires is way beyond my sense of fun. That is risky beyond fun for me. So is skydiving and bungee jumping.

    My point - we each get to choose what entertains us. For my buddy, who has landed a stock Super Cub on a 400’ strip with 30 foot obstacles at each end on stock tires, the big tires are simply a fashion statement, and he does not care about the cost in $ and performance.

  34. #74
    mvivion's Avatar
    Join Date
    Jun 2003
    Location
    Bozeman,MT
    Posts
    11,110
    Post Thanks / Like
    If he doesnt care about cost, buy a set of 29 inch Airstreaks. If you’re gonna make a statement, go big.

    MTV
    Likes Crash, Jr. liked this post

  35. #75
    BC12D-4-85's Avatar
    Join Date
    Feb 2016
    Location
    Fairbanks, AK.
    Posts
    2,525
    Post Thanks / Like
    And paint the raised letters white.

    Gary
    Likes Gordon Misch, Crash, Jr. liked this post

  36. #76
    Crash, Jr.'s Avatar
    Join Date
    May 2015
    Location
    Anchorage, AK
    Posts
    265
    Post Thanks / Like
    Quote Originally Posted by BC12D-4-85 View Post
    And paint the raised letters white.

    Gary
    I'd go yellow. Already have some yellow sticker kits ready to go for the 29's. Gotta color match if you're really gonna make a statement. I'd rather look good than be good any day.
    Likes BC12D-4-85 liked this post

  37. #77

    Join Date
    Sep 2003
    Posts
    7,272
    Post Thanks / Like
    He isn’t reading this. Already ordered the 26” set above -and waiting for mag wheels, ‘cause they are lighter. My next update will be when the winter winds get here - if they ever do. Lousy year for wind at MYF so far.
    Likes Coondog liked this post

  38. #78
    hotrod180's Avatar
    Join Date
    May 2008
    Location
    Port Townsend, WA
    Posts
    3,228
    Post Thanks / Like
    Quote Originally Posted by bob turner View Post
    And Hot: this is not Alaska. There are no places in SoCal to legally practice big props and long rocks. All of the giant-wheeled Cubs here are for “appearance” only.
    And on pavement, the larger tires (29 and 31) cut the crosswind capability to about half. They don’t dare join me on our 20 kt crosswind days (neither do the Cherokees - I have the 11th busiest airport to myself).
    I dunno about true, hardcore "off airport",
    but there's a thread on BCP about grass or dirt strips near San Diego.
    It's just starting on the 3rd page of discussion over the last 3-1/2 years, so there are some nearby options.

    https://backcountrypilot.org/forum/s...t-strips-20457
    Cessna Skywagon-- accept no substitute!

Similar Threads

  1. 8" Tailwheel Tire
    By 180_jeff in forum Cessna: C180/C182/C185
    Replies: 0
    Last Post: 10-27-2018, 11:24 AM
  2. Tire interchange and legality 26" and 35"
    By slowjunk in forum Cafe Supercub
    Replies: 7
    Last Post: 05-04-2015, 09:54 AM
  3. 26" tire pressure
    By bob turner in forum Cafe Supercub
    Replies: 19
    Last Post: 03-06-2015, 11:53 AM
  4. Tire Pressure for 31" ABW
    By Colorguns in forum Cafe Supercub
    Replies: 49
    Last Post: 03-01-2015, 04:24 AM

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
  •