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  1. #126
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    Quote Originally Posted by Chromehorn View Post
    Maybe I'm missing something here, or am just too dull or inexperienced of a biker but this sounds interesting to me. So are you saying that you are gluing an entire tube to the inside of the tire? If this isn't what you are saying, I'm wondering how things would work if you did do this? If the tube had sealant in it, would this be as effective as tubeless so far as the puncture sealing benefits of tubeless are concerned? I guess it would mostly depend on how well you have the tube glued to inside of the tire.

    I'm looking to try tubeless this coming weekend pretty much only for the benefit of cutting down on all the silly flats I get from goat heads and thorns in general.

    Let the commence...
    I was not very clear on that. No you would do the split tube method but you bond the tire bead only to the split tube before you inflate it. So you have the same system but the tube and tire will stay one unit when it is removed.

  2. #127
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    Quote Originally Posted by exp18 View Post
    I was not very clear on that. No you would do the split tube method but you bond the tire bead only to the split tube before you inflate it. So you have the same system but the tube and tire will stay one unit when it is removed.
    Gotcha. Any particular type of glue or cement used? Does that cause issues if for some reason you need to put a tube in? Or maybe a better question would be is the split tube permanently bonded to the tire? I like the sounds of this setup. Seems it would be "cleaner".
    Chromey

  3. #128
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    There is a good thread that as a great how to do it ( Tubeless fat bike made easy ) the next post is one from me that shows the glue and cleaner i use but there are a lot of them out there.

  4. #129
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    Thanks for the tip. Looked at the thread and see what your saying now.
    Chromey

  5. #130
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    Quote Originally Posted by mikesee View Post
    Current operating theory is that the amount of torque on the beads from riding the local chunk (think slow speed rock crawling, even on XC rides) means that they are constantly getting pulled free of the rim, maybe even multiple times per ride. Not enough to burp them (probably because I'm not brave enough to ride them hard yet) but enough that I need to add air every ~20-30 minutes or so when riding. Sometimes there's a visible spot of sealant, sometimes not.
    Mike, you probably already know this, but 'back in the day' when snow riders were first running super low pressures with the 44mm SnowCat rims, some people would have problems with tearing off their valve stems because the tube adhered to the tire and the tire slipped on the rim. The solution was a few dabs of super glue between the rim and the tire which had just enough holding power to keep the tire from slipping. It was only put on one of the beads so you could still change your tube by popping the other bead off. This technique, applied to a tubeless set-up might solve your problem if your theory is correct.

    For those of you who don't know who 'MikeSee' is, he is one of the greatest endurance racers of all time and probably has more miles on a fat bike then everyone else on this thread put together. So his opinion should certainly carry some weight.

    I for one just built up my new bike with Holy Rolling Darylls and 45NRTH tires. I was just going to run lighter tubes and not deal with the hassle of tubeless. However, when I got a flat (borrowed tube came with a hole already in it) I noticed that the bead was holding extremely tightly, took a surprising effort to pop it loose so I could get the tube out. So I'm going to go head down to the basement this morning and give a tubeless set-up a try. If it works out I'll test it on my ride this afternoon.
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  6. #131
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    tubeless is a weight looser

    Well, I went into my basement and got the bead to seal up easily with my existing rim tape (a 2" strip of reflective fabric and two 2" strips of Scotch strapping tape). However, I decided that this tape might be vulnerable to liquid penetration damaging the adhesive so an extra layer of Gorilla tape would be a wise investment for reliability. I was all set to go, but then I started doing some math:

    1) each scoop of sealant is 60 grams, people are reporting using 3-6 scoops... lets go with 4 scoops for 240 grams.

    2) my Stan's valve weighed in at 7g

    3) then there is the tape. I didn't have any of the extra wide Gorilla tape handy, but I wrapped the normal sized stuff around the inside of my rim, the took it off and measured it (~64" of tape) and then balled it up and weighed it at 40 grams. If you extrapolate that density for the extra wide stuff that will cover your rim in one swipe, that's 63 grams.

    So assuming you are starting with the same rip strip either way, the lightest configuration possible with Gorilla tape tubeless is 310 grams. using 3 strips of standard width Gorilla Tape and 5 scoops of sealant you'd be looking at 427 grams.

    Compare that to:

    Surly 4.0" tubes: 436 g (average of 2)
    Specialized 2.3-3.0" tubes: 280 g (279/279/283)
    Q-Tube Superlight 2.4-2.7": 256 (claimed)

    Conclusion: if weight is your primary concern using a 2.5"+ tube will give you the lightest configuration. A tubeless set-up would range from essentially the same weight as the Surly 4.0" tubes to saving you just over 1/4 pound per wheel depending on the exact configuration.

    Discussion: Personally, I feel that with a lower weight, less effort in the initial setup and easier on-the-trail repairs, lighter tubes are the way to go. I think both would be equally durable with my wheel set up (45Nrth tires and Rolling Daryll rim) based on how well the bead seated. This is probably a result of these parts being designed to fit tightly together so as to reduce wheel slippage at low tire pressures.

    People who ride in rocky terrain or areas with a high potential for punctures seem to strongly prefer the tubeless setup since it is more flat resistant The weight penalty for this set-up is small and would be worthwhile for that use. However, I will be using my bike almost entirely in snow, and in the past 5 years of snow riding (using 44mm SnowCat rims, 2.5" tires and lightweight tubes) I have experienced a total of 1 flat.

    What I want to know is how is performance actually effected by running tubeless on a fat bike? Would there be perceptibly less rolling resistance? Would there be more traction? Are these things quantifiable in any way or are we stuck relying on user reports only?
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  7. #132
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    Friends don't let...

    ...friends run tubes!

    Great slogan for a tee-shirt graphic???

    "tubeless is a weight looser"---that I must take exception to!

    If somebody's a serious weight-weenie then use a cannula and suck the sealant back out of the tire once all the leaks have stopped. I'm pretty sure there'll be less than an ounce left behind!

    As I said in an earlier post:

    I can only speak to doing tubeless ghetto-style on Large Marge's but it is the way to go; not trouble-free but much less trouble than with tubes. (I ride in a puncture-rich environment!)

    Since I run a sealant anyway (Slime) if I'm running tubes my weight saving is in the tubes; 1~2 # depending---all the other weights cancel out.

    What I've been running is either Stan's or SlimePro when I seat the tires (the latex tends to "glue" the tire in place) and then I top off with plain ol' Slime (like what you'd use in your car; comes in the handy gallon size with a pump)---it'll take a couple of weeks before all the leaks seal up.
    Everything else being equal tubeless will always be lighter...

    (BTW; I have run "light" tubes; I've had them fail (split open) for no good reason with the bike just being parked---I don't trust them at all)

    I suppose if one only rides on the beach or on the snow then tubes might be OK for a fat bike. But where I ride in semi-rural California besides the usual punctures from nails, screws and glass we've got 4 or 5 thorny plants eager to flat. Here's some "goat heads" (or "puncture vine") in a 29er tire:

    BTW; this was in a "tubed" set up w/Slime---even though each tire had +/- 50 punctures they all sealed up. The next time I wasn't so lucky; had to pump the rear every couple of miles to complete the ride---that bike is now tubeless. I've had similar situations with the fat bikes; I haven't taken any pictures though.

    Plus something that's not considered very often is that because of the greater tire width a fat bike is 2 or 3 times more likely to contact materials that will give a puncture. (True; with the lower ground pressure objects may be less likely to have the force to penetrate --- but with some of these needle-sharp thorns it doesn't seem to matter)

    Just to add to the discussion; here's a Nate where the sealant can be seen weeping from porosity around the cords:

    The sealant (Slime in this case) is doing it's job---I only need to add air every couple of weeks. BTW; this condition showed up only after running the tire at sub-5 psi for an extended length of time. Probably damaged the sidewall.
    The views and opinions expressed here are those of the author and do not represent any policy of the CA Dept. of Parks & Rec.

  8. #133
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    Quote Originally Posted by exp18 View Post
    I was not very clear on that. No you would do the split tube method but you bond the tire bead only to the split tube before you inflate it. So you have the same system but the tube and tire will stay one unit when it is removed.
    this would be a tubular clincher tire when done like this, no?

    I have seen a tubeless setup for motocross motorcycle rims that uses a small bicycle tube stretched around the rim(whole, not split). this is inflated after the tire is installed, just enough to seal the beads to the rim, then a second valve that goes through the "inner" tube is used to inflate the tire. I think this works only with rims that are much narrower than the tire though.

    I like the idea of gluing a split tube to the tire to make a tubular clincher fatbike tire. Maybe you could even go as far as to use some cloth material across the bottom, glued to the split tube, and sew it all together. then you would have true tubular fat tires for clincher rims.

  9. #134
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    Quote Originally Posted by FishMan473 View Post
    Conclusion: if weight is your primary concern using a 2.5"+ tube will give you the lightest configuration. A tubeless set-up would range from essentially the same weight as the Surly 4.0" tubes to saving you just over 1/4 pound per wheel depending on the exact configuration.
    I think we should consider the location of the weight, which is why we're so concerned with rotating mass (especially the rims and tires) in the first place: it makes more of a difference there. Considering that all the weight of a gorilla tape or ghetto tubeless rim strip is at the rim, the radius of the rotation is smaller compared to tubes, which put more mass further from the center.

    Also, when you accelerate not all of the liquid starts to move at once. While the reading on a stationary scale might be the same, 100 grams of liquid in the tire doesn't equal 100 grams of solid rubber when it comes to a rotational acceleration when you ride.

    I'm not saying these things make huge differences, but I think they can not be compared directly gram for gram.

    Quote Originally Posted by FishMan473 View Post
    What I want to know is how is performance actually effected by running tubeless on a fat bike? Would there be perceptibly less rolling resistance? Would there be more traction? Are these things quantifiable in any way or are we stuck relying on user reports only?
    Rolling resistance can be measured fairly easily. The hardest part would be to ensure all other variables are fixed as carefully as possible. This kind of tests provide irrefutable evidence.

    The "liquid effect" of the sealant could be measured with a fairly simple system with the wheel and tire on a truing stand and some kind of weight or spring that pulls on a chain to rotate the wheel, and an accelerometer to record the results.

    For me the feeling of a reduced rolling resistance and improved acceleration and traction is enough. Even if it's mostly placebo, I prefer riding tubeless. The psychological effect of a perceived advantage (even if it's impossible to measure) is a well documented and proven phenomena.

  10. #135
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    Ah you're goat heads are the same as our "3-corner-jacks".

    The sole reason i went tubeless many years ago.

    Carry a 1 spare tube, roll over a jacks patch and you end up with 10-30 punctures in both wheels = Game over (hope your wern't too far from home)
    Attached Thumbnails Attached Thumbnails Tubeless vs tubes??-104954124_y1it7mhc_0490prickles.jpg  

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  11. #136
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    Well, not exactly...

    Quote Originally Posted by ozzybmx View Post
    Ah you're goat heads are the same as our "3-corner-jacks".

    The sole reason i went tubeless many years ago.

    Carry a 1 spare tube, roll over a jacks patch and you end up with 10-30 punctures in both wheels = Game over (hope your wern't too far from home)
    ..."our" goatheads; they're an import from southern Europe---how'd Australia be so fortunate to have them native?

    Pretty big problem here in the States; here's a link to the UC Davis page: Puncturevine Management Guidelines--UC IPM

    Good Wiki page for those lucky enough not to be familiar with them: Tribulus terrestris - Wikipedia, the free encyclopedia

    Here's the pod in its stages of dissemination:

    Almost always lands with a point up!

    Here's a real short clip of me hopping a curb and rolling squarely across a patch; if YouTube is set to HD you can see the seed pods stuck to the tire---probably 2/3 of them have punctured the tube:
    The views and opinions expressed here are those of the author and do not represent any policy of the CA Dept. of Parks & Rec.

  12. #137
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    Quote Originally Posted by autodoctor911 View Post
    I have seen a tubeless setup for motocross motorcycle rims that uses a small bicycle tube stretched around the rim(whole, not split). this is inflated after the tire is installed, just enough to seal the beads to the rim, then a second valve that goes through the "inner" tube is used to inflate the tire. I think this works only with rims that are much narrower than the tire though.
    What you're talking about is the Neutech TuBliss system. It's really an inflatable beadlock that holds a standard tire in place on a standard rim. The orange part is an aluminum plate that holds the outer tire valve stem - and deflects the innerinnertube around it. It also is a "conventional" beadlock to hold the tire where the tube is deflected.

    You tape the spoke holes just like bicycle tubeless, then put the "inner tire&tube" in place. I've been running them on a Suzuki DR350 for about a year w/o issue.

    I've been working towards the same thing for fatbikes, but I'm taking my time working things out so I'm sure it's really close before I try riding it. The basic idea for the "inner tire" is to split a small 26er road slick and sew in a strip of material to fit the fat width:

    The plastic bit sticking up is the transfer tube that let's you air up the outer tire:


    I need to do the next improvement on the transfer tube (now that I've got one that won't crush) to prevent splitting at the ends. Also, the web strap would probably soak up a lot of sealant - so I'm looking at sourcing some sailcloth to replace it.
    This isn't a "you're doing it wrong" topic.

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  13. #138
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    They are a nightmare, ok when green as the little thorns are soft, once they dry up they are a ride killer if you run tubes.
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  14. #139
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    Anyone have any idea how well a tubeless setup would work in temps down to -15 F or lower? I really want to go tubeless, but with how cold it's been this winter so far, I'm afraid that the really cold temps would be detrimental. Thoughts? Successes?

  15. #140
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    Quote Originally Posted by blockphi View Post
    Anyone have any idea how well a tubeless setup would work in temps down to -15 F or lower? I really want to go tubeless, but with how cold it's been this winter so far, I'm afraid that the really cold temps would be detrimental. Thoughts? Successes?
    Stan's is only good to -20 F before it starts freezing.

  16. #141
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    Quote Originally Posted by wadester View Post
    I've been working towards the same thing for fatbikes, but I'm taking my time working things out so I'm sure it's really close before I try riding it. The basic idea for the "inner tire" is to split a small 26er road slick and sew in a strip of material to fit the fat width:

    The plastic bit sticking up is the transfer tube that let's you air up the outer tire:


    I need to do the next improvement on the transfer tube (now that I've got one that won't crush) to prevent splitting at the ends. Also, the web strap would probably soak up a lot of sealant - so I'm looking at sourcing some sailcloth to replace it.
    I guess if weight savings was not the main goal, you could run a 26x2" tire and tube, and run a second valve that snaked around them, and run a higher pressure in the inner tire, and you would have a setup that would get you home even if the outer tire was completely flat.

  17. #142
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    Quote Originally Posted by autodoctor911 View Post
    I guess if weight savings was not the main goal, you could run a 26x2" tire and tube, and run a second valve that snaked around them, and run a higher pressure in the inner tire, and you would have a setup that would get you home even if the outer tire was completely flat.
    First "proof of concept" did something like that, but a 26x2 wouldn't stretch across the width of the rim (at least on a 100). A FatFrank 26x2.35 worked, but took up too much volume. Running the outer tire at "normal" pressure would have had you running on both tires. Current version is very low profile, as you can see. Using a 26x1.25 slick with an insert keeps it short. Still should work as a "run flat" insert to get you home, since it will still hold the beads in place
    This isn't a "you're doing it wrong" topic.

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  18. #143
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    Quote Originally Posted by blockphi View Post
    Anyone have any idea how well a tubeless setup would work in temps down to -15 F or lower? I really want to go tubeless, but with how cold it's been this winter so far, I'm afraid that the really cold temps would be detrimental. Thoughts? Successes?
    I haven't had much problem with Stan's freezing, but I have never had it seal a hole below 0C.

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