Page 1 of 2 1 2 LastLast
Results 1 to 25 of 26
  1. #1
    mtbr member
    Reputation:
    Join Date
    May 2011
    Posts
    724

    29+ 3.0" contact patch -vs- 26 inch 3.8" contact patch

    How does a 29+ 3.0" contact patch compare to a 26" wheel 3.8" at low psi?

    Anyone measure both?

    How about wheel weight?

  2. #2
    mtbr member
    Reputation:
    Join Date
    Apr 2011
    Posts
    2,211
    Have not measured, but have seen both side by side. A 3" Knard is dwarfed by a 3.8" Knard. Not only is the 3.8" almost an inch wider, it is also a lot taller than the 3".

    That is all I have to offer.

  3. #3
    mtbr member
    Reputation:
    Join Date
    Jul 2004
    Posts
    130
    I ride the Krampus when there's only an inch or so on the ground, and compared to my pals running Dillingers, I'm dead in the water on climbs. Knards run out of traction really quickly compared to fat tire. Now, compared to the guys on regular 29" tires, the Knards kick butt. It's definitely an in between size, and as soon as the 29" Dirt Whizards shows up, that will be more Krampus tire. Definitely want more traction, especially in the light snow.

    When the snow is deeper, it's back to the Nates and the Fastback.

  4. #4
    mtbr member
    Reputation:
    Join Date
    Sep 2008
    Posts
    338
    The size of the contact patch is largely a function of rider+bike weight and the inflation pressure of the tire. One can run a significantly lower pressure in a 3.8" tire than in a 3.0" tire, so a 3.8" set-up can and should have a larger contact patch. But if you're running the same psi, the size of the contact patches will be nearly identical (ignoring minor factors like tire stiffness).

    A 29+ contact patch will of course be generally longer and narrower than a 26x3.8 contact patch.

    It's hard to get around the extra width of 0.8" of tire and 60mm+ rim so a 29+ set-up will almost always be lighter. That said, I'm guessing you could come up with a fairly light 26" set-up using a 47mm drilled single-wall rim and a Black Floyd.

  5. #5
    mtbr member
    Reputation:
    Join Date
    May 2011
    Posts
    724
    Quote Originally Posted by jnroyal View Post
    It's hard to get around the extra width of 0.8" of tire and 60mm+ rim so a 29+ set-up will almost always be lighter. That said, I'm guessing you could come up with a fairly light 26" set-up using a 47mm drilled single-wall rim and a Black Floyd.
    Thanks. Yeah LOVED the traction, hated the fat bike wide q factor. That's where I am thinking plus size so I can keep the same 73mm bb width. If I ride in snow, it's hard packed and typically a studded 2.0" works as well if not better than true fat without studs. That's my dilemma...

  6. #6
    mtbr member
    Reputation:
    Join Date
    Apr 2008
    Posts
    71
    My buddy has a Krampus and he manages/struggles on most days with the rest of the crew who are all on Fatbikes. That said, he's built like a TDF rider 5'7" and 125lbs soaking wet, with great balance and huge horsepower. He's able to make up for the lack of float in other ways but it's a LOT of work!

    Personally I think you'd just get used to the Q factor after some time on the bike. Admittedly it's an adjustment each season but it's probably good for the body to change things up.

  7. #7
    mtbr member
    Reputation: Tibor's Avatar
    Join Date
    Nov 2011
    Posts
    138
    29+ 3.0" contact patch -vs- 26 inch 3.8" contact patch-38vs30.jpg

    a pic from last year... its an 26"x3" tire... but the width should be the same...

  8. #8
    mtbr member
    Reputation:
    Join Date
    May 2011
    Posts
    784

    Re: 29+ 3.0" contact patch -vs- 26 inch 3.8" contact patch

    Quote Originally Posted by Tibor View Post
    Click image for larger version. 

Name:	38vs30.jpg 
Views:	288 
Size:	210.2 KB 
ID:	864461

    a pic from last year... its an 26"x3" tire... but the width should be the same...
    This pic doesn't really show much. For a more accurate comparison, both tracks would have to be in the same frame, not two different photos shopped together.

    I don't have a Krampus though, so...

    Sent from my Nexus 4 using Tapatalk

  9. #9
    mtbr member
    Reputation: Tibor's Avatar
    Join Date
    Nov 2011
    Posts
    138
    i shot both pics from the same hight... maybe i do a photo tomorrow...

    gazza vs nate...

  10. #10
    is buachail foighneach me
    Reputation: sean salach's Avatar
    Join Date
    Sep 2007
    Posts
    5,848
    Quote Originally Posted by Tibor View Post
    Click image for larger version. 

Name:	38vs30.jpg 
Views:	288 
Size:	210.2 KB 
ID:	864461

    a pic from last year... its an 26"x3" tire... but the width should be the same...

    There is no way that photochop is anywhere near accurate. How do I know?

    WW '2.55', Stout, Endomorph, all ridden by me, within a 5 minute time frame, no 'photoshop' involved(except the border). Your photo makes the 29 x 3 look 1/3 the width of a Larry.


    endo by anrothardonn, on Flickr

  11. #11
    mtbr member
    Reputation:
    Join Date
    Jul 2004
    Posts
    130
    If you want to measure the contact patch to see what's really happening, don't do it by rolling the tire across snow, lift the rear end up, hop on the bike, and get a non-moving "footprint" of each tire combo. A 26" x 3" Gazzolida at 25psi will be a lot smaller than a 29" x 3" Knard at 12psi. And a 26" x 4" fatty will be bigger than the Knard. But that will show you what's gripping the ground at any given time while you're riding.

    I'll try and get a Knard footprint vs a Nate footprint tomorrow, we've got snow in the forecast tonight.

  12. #12
    mtbr member
    Reputation:
    Join Date
    May 2011
    Posts
    724
    Quote Originally Posted by RickyB View Post
    If you want to measure the contact patch to see what's really happening, don't do it by rolling the tire across snow, lift the rear end up, hop on the bike, and get a non-moving "footprint" of each tire combo. A 26" x 3" Gazzolida at 25psi will be a lot smaller than a 29" x 3" Knard at 12psi. And a 26" x 4" fatty will be bigger than the Knard. But that will show you what's gripping the ground at any given time while you're riding.

    I'll try and get a Knard footprint vs a Nate footprint tomorrow, we've got snow in the forecast tonight.
    Thanks, yeah ^this^ seems like the smart thing to do.

    I'm not really riding really snowy trails. *MAYBE* a few times a year and as of right now and I can ride my 29er with studded Nokians as fast if not faster in sections than than my friends on their 4.0+ fat bikes (no studs) on the packed out trails.

    Basically I am looking for fat bike traction (more for dry trails) but I don't want a 26" fat bike because IMHO the wide q factor pedals like poop to put it bluntly. Also, I'm done riding 30+ pound rigid bikes. Thinking custom ti 29+ with segmented ti fork in the 20-ish pound range on the 52mm Stans 29er hoops they have coming out some time soon.

    If I have to go 26, then I have to go 26 - but I don't want the rubber weight, rim weight, and wide q factor that goes along with it. The Stans light weight 500-ish gram 29+ rim and Knards, Dirt Wizards or soon to be released Vee 29+ sure look appealing. So that's why I am interested in what the contact patches of say a 170mm bb 26 inch 4.8 look like compared to a 73mm bb 29+ 3.0" look like.


  13. #13
    mtbr member
    Reputation:
    Join Date
    Apr 2011
    Posts
    2,211
    ^Sounds like you are a ww and really have no business in the fatbike world.

    The type of riding you do can be accomplished on a 29+ bike. Leave fat to the types who pay the weight penalty to play in the fun stuff.

  14. #14
    mtbr member
    Reputation:
    Join Date
    Jul 2004
    Posts
    130
    GSJ - if you go back to the fat-bike.com article from Interbike, that 52mm rim is the 26" rim that Stans is making, not a 29er. At 500 grams, and only 52mm, he didn't really do his homework. Fat tires were designed for fat rims, otherwise the shape is compromised. I wouldn't want to push a Nate hard through a corner on a 52mm rim at 5psi, I'd worry about rolling it off the rim.

    Overall weight is a tricky thing, and so is Q factor. I'm going to guess you don't like wide handlebars and short (50-70mm) stems. It took me a while, but if I get in a bike with 26" bars, I hate it now. All my bikes are just over 30", and that's what works for me. I think it opens up my chest and I breathe better, and I have more control of the bike at high speed, not as twitchy as narrow bars for sure. Do I hit more trees? Absolutely, and that sucks, but I know where the tight gaps are, and just need to focus. I'm 5'11" and the wider Q factor doesn't bother me. If I also was road riding, it would probably drive me crazy.

    Here's my bottom line. I started riding a Mukluk2 just for fun. Then I switched to a Fatback with some decent components, and it was more than fun, it was fast, Strava says so. I'm in the process of putting the Fatback on a diet to see what it can really do. It's 31.25 pounds now with Nates on 90mm rims, and the new breed of carbon fatties are hitting 23 pounds. If I get down to 26 I'll be ecstatic, and I'm not giving up my Nates. Other tires roll faster, and are lighter, but nothing grips like a Nate for all year long riding. And yes, I ride this all 4 seasons, along with my Krampus that has front suspension. I'm finding that the more fun I have, the faster I ride, and weight isn't the limiting factor.

  15. #15
    Nuts
    Reputation: bdundee's Avatar
    Join Date
    Feb 2008
    Posts
    4,849
    I don't think 29+ ever should have been in the fat forum in the first place, they are not fat!!
    And I love beer!!

  16. #16
    mighty sailin' man
    Reputation: MiniTrail's Avatar
    Join Date
    Jan 2008
    Posts
    4,720
    ^ we've had the 3" equipped 1X1s since the start

    can't say they don't belong
    Quote Originally Posted by davidarnott
    wheelies, beyond being the best way over any sort of obstacle, both above or below, are are the steedliest expresstion of joy

  17. #17
    Nuts
    Reputation: bdundee's Avatar
    Join Date
    Feb 2008
    Posts
    4,849
    Quote Originally Posted by MiniTrail View Post
    ^ we've had the 3" equipped 1X1s since the start

    can't say they don't belong
    Yeah I guess that makes sense, my first fat bike was almost a 3.0 but everyone said real fat was so much better.
    And I love beer!!

  18. #18
    mtbr member
    Reputation:
    Join Date
    May 2011
    Posts
    784

    Re: 29+ 3.0" contact patch -vs- 26 inch 3.8" contact patch

    Someone call the forum police

  19. #19
    mighty sailin' man
    Reputation: MiniTrail's Avatar
    Join Date
    Jan 2008
    Posts
    4,720
    I'm surprised they still let us discuss 3.8
    Quote Originally Posted by davidarnott
    wheelies, beyond being the best way over any sort of obstacle, both above or below, are are the steedliest expresstion of joy

  20. #20
    mtbr member
    Reputation: nvphatty's Avatar
    Join Date
    Mar 2012
    Posts
    5,519
    Quote Originally Posted by MiniTrail View Post
    I'm surprised they still let us discuss 3.8
    i resemble that

  21. #21
    mtbr member
    Reputation:
    Join Date
    Jan 2013
    Posts
    127
    GSJ1973,

    When I got my 29er+ wheels I was surprised by how fat the tires are compared to my 3.8 nate. That said, it feels much different. The volume just isn't there on a 29er+ the same way it is on the 26er fat tire. The ride is completely different. It is hard to say how that platform would do in the snow because there are not many tires available. The knards aren't snow worthy compared to nates and although the dirt wizards look like an improvement, they are still a far way off from the aggressive tire options we have in 26er fat tires.
    Everyone is different with how they respond to Q factor and I felt as though I had made a mistake after buying my fat bike because of the wide Q and my narrow hips. But after an adjustment period of a few weeks it hasn't been an issue and I have had zero knee pain since riding the fat bike. Good luck with your purchase.

  22. #22
    mtbr member
    Reputation: lancelot's Avatar
    Join Date
    May 2006
    Posts
    933
    Quote Originally Posted by jonshonda View Post
    Have not measured, but have seen both side by side. A 3" Knard is dwarfed by a 3.8" Knard. Not only is the 3.8" almost an inch wider, it is also a lot taller than the 3".

    That is all I have to offer.

    29+ Knard is almost 50mm larger in diameter than a 3.8" Knard. It's even taller than a Bud. I own both but prefer to ride my fattie in snow and my 29+ in dirt.

    http://surlybikes.com//uploads/downl...Geometries.pdf
    The LPG

  23. #23
    mtbr member
    Reputation: marathon marke's Avatar
    Join Date
    Sep 2012
    Posts
    307
    What ntm1973 said about hip width being a factor in wide Q factor tolerance makes sense. I also think leg length is something to consider. Even though I have narrow hips (including a fake one after a spill on black ice last year), my long legs might be why I've never had a problem with my Moonlander. Longer legs decreases that angle. I also come from riding 12,000 a year on my road bike, and haven't had a problem making the switch.
    - Mark Ehlers
    The Prodigal Cyclist

  24. #24
    mtbr member
    Reputation:
    Join Date
    Apr 2011
    Posts
    2,211
    Quote Originally Posted by lancelot View Post
    29+ Knard is almost 50mm larger in diameter than a 3.8" Knard. It's even taller than a Bud. I own both but prefer to ride my fattie in snow and my 29+ in dirt.
    Sorry, I meant that the physical distance from the inner to outer diameter of the tire is a lot larger. Like the difference from larry to bfl.

  25. #25
    mtbr member
    Reputation: lancelot's Avatar
    Join Date
    May 2006
    Posts
    933
    I hear ya.
    The LPG

Page 1 of 2 1 2 LastLast

Similar Threads

  1. Replies: 64
    Last Post: 09-01-2014, 07:43 PM
  2. Replies: 7
    Last Post: 06-14-2014, 10:29 AM
  3. Contact Patch
    By Cartski in forum Fat Bikes
    Replies: 41
    Last Post: 07-20-2013, 02:52 PM
  4. Replies: 16
    Last Post: 11-23-2011, 05:29 AM
  5. 29er tire contact patch, mud
    By Drea in forum 29er Bikes
    Replies: 13
    Last Post: 10-05-2011, 11:11 PM

Posting Permissions

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