GBS' Fatty Tubeless History & How-to
Years ago we were hanging out after work and one of our employees started talking about how he wished he could set his Pugsley up tubeless. We all knew this had to be possible - we'd never seen it done, but it has to be a thing... right?
A few Google searches later we stumbled across a video shot in someones shed in the middle of the Great White North (Alaska, eh), with poor audio, and low resolution... After watching it a few times, we finally got the process figured out. Some Gorilla tape, a few matches, some ether and a missing eyebrow later, we had tubeless. He rode his new tubeless system without issue for months, outstanding!
We decided to offer tubeless setup commercially, granted, we were not excited about using exploding-tire method to set up customer bikes tubeless, so we decided to experiment further. After several attempts and nearly burning our compressor out trying to seat the beads, we realized that the tires typically adhered themselves to the rim on their own once inflated with a tube.
And thus, our tubeless technique was born.
After converting many fatties over to the dark side, we knew many were approaching the setup on their own - rad! We all started by wrenching on our bikes in our garages. We thought we'd put a how-to video together for all the DIYers out there. There's a lot of techniques out there if you're surfing the forums; over the past few years we've averaged over 30 fatbike tubeless conversions per season, we've refined our method and it's tried and true.
If video watching isn't quite your thing, here's a brief run-down on how you, too, can do the tubeless.
- If starting with a tubed tire, deflate tube by removing valve core. Remove tire and tube.
- Ensure that your rim strip is properly installed and trim to 5-10mm below the curved portion of the inner rim bed to ensure proper adhesion of tape.
- If using Gorilla tape, apply 1 wrap of tape the entire circumference of the rim, starting opposite the valve, and overlapping 4-6", ensuring the tape extends from the base of the rim sidewall on both sides, while pulling taut and pressing the tape into the curvature of the rim.
- If using Orange Seal tape, begin opposite the valve, apply 2 layers of wrap to the entire surface of the inner rim bed. Ensure that the tape covers both bead seats - on some rims you may need to apply a total of 4 wraps (2 per side).
- Once taped, firmly press the tape to the rim around the valve hole, and poke a small hole with a dental pick, sharpened spoke, or #1 Phillips screwdriver.
- Reinstall the valve core install the tire with your tube. Be sure that the direction of the tire is correct prior to moving forward - this will be the last opportunity to get that correct. (The obsessive mechanic in me suggests to center the logo over the valve, too). We recommend lightly dusting the tube with some talcum or baby powder to keep the tubes friction from dislodging your tape.
- Let the tire sit for 5-10 minutes - more if the rubber is cold.
- Deflate the tube by removing the valve core and carefully unseat only one bead of the tire from the rim, being sure to keep the opposite bead seated.
- Remove the tube
- Insert your tubeless valve and tighten the nut firmly to ensure a proper seal between valve and rim. Remove valve core.
- Install the unseated tire bead.
- Inflate the tire (without valve core). Depending on the inflation tool you're using with your compressor, you may need to lay the wheel on its side, unseated bead facing downward (gravity is your friend).
- Once the bead pops and settles into place, you may allow the tire to deflate.
- Attach a hose to the core-less valve, and insert your choice of sealant into the tire. We recommend 4oz if using Orange Seal tape, or 8oz if using Gorilla Tape.
- Install valve core
- Inflate to 15psi and shake around to distribute sealant along the bead to seal any small leaks, repeat as needed until the tire holds 15-20psi without leaking.
- Maintain 15-20psi for the next couple of days to help establish and retain the seal between tire and rim. We recommend taking your bike for a brief ride to help distribute the sealant and further establish the tubeless setup.
- Enjoy the new system!
There's lots of variables with fatbike tubeless, here's a few pointers that we've found help out a lot.
WHY GORILLA TAPE?
We've experimented with other, lighter options, but we've found that Gorilla Tape strikes the perfect balance between long-term durability and resilience when it comes to resisting breakage or tearing under air pressure. It's also, hands down, the stickiest tape out there; as far as readily available tape, it's going to hold a seal better than anything else we've found. Gorilla Tape is also available in two widths (okay, three, but no one will use 1" tape for a fatty), to best suit your rim needs - on many rims wider than 90mm, you'll likely need two wraps of tape to span from bead-to-bead, but you can use one wide, and one narrower to keep weight down.
Granted, it also has some drawbacks. It's heavy (compared to other tapes), but it's not that heavy, weighing in at approximately 80g per wheel, it's a small sacrifice for that stickiness. It's also prone to absorbing a certain amount of your sealant, while forming an air-tight seal, it's not 100% impermeable. As such, we recommend doubling the amount of sealant used with Gorilla Tape over other tapes out there.
I'VE HEARD ABOUT FOLKS USING SOTCH CLEAR DUCT TAPE - IT'S LIGHTER, WHY DON'T YOU USE THAT?
We heard many were using Scotch clear duct tape with great success, claiming that even though they needed more wraps for durability and width-coverage, so we thought we'd give it a shot.
Fail. We tried multiple times, but the end result was always the same, the adhesion on the tape was just weak. Every time we'd inflate the tube to set the tape in place, then go to set it up tubeless, we'd inflate the new-tubeless, and shortly thereafter find that the system was losing substantial amounts of air through the tape / rim strip. When we'd pull the tire off to inspect, we found that in every circumstance, no matter the quantity of wraps, the tape simply didn't stick to itself, nor the rim as much as it needed to.
If you've used this tape and have had luck, or any other tape - fantastic! We just found it to be unreliable in practice, and as such don't recommend the use of the tape, but if you're having luck with it, we won't stop you to continuing to use it.
YOU'VE MENTIONED ORANGE SEAL TAPE, IS THAT BETTER?
Absolutely. Within the last year, Orange Seal - a sealant company out of Texas - released their own version of fatbike tubeless tape... it's basically REALLY big Stan's Tape, but even more flexible, and orange. Because orange.
Like Gorilla Tape, Orange Seal offers their tape in two widths to fit a variety of needs (hey! We keep this stuff in stock on the sales floor!). We've found that it works best to double-wrap to add some thickness to the bead socket, and to help prevent leaks through the rim. Orange Seal tape is also incredibly light - we haven't weighed the difference between 1 wheel's worth of OS vs. GT, but it's substantially less, think 70% weight savings on tape alone.
To top that off, because the nature of Orange Seal's tape is non-absorbent, you can use 50% less sealant than you would use in a Gorilla Tape or other variety of duct tape tubeless setup. Sweet! More weight savings! Drop your tubeless setup weight by over 50% total.
WHAT TUBELESS VALVES SHOULD I USE?
Assuming you're using a single-wall rim, look for a tubeless valve that allows you to tighten the valve nut all the way down against the rim and form a seal between the valve gasket and rim. Certain valves are designed to be used in deeper rims - DT Swiss, Enve, American Classic, etc. We recommend using Stan's No Tubes valves, they're tried and true in our shop, and readily available.
HOW ABOUT 27TPI VS. 120TPI TIRES?
We've noticed the optimal tire casing is one with a higher thread count, and a folding bead. That said, we have had success with our rental / demo fleet with long-term reliability with both 27tpi and 120tpi tires; but if we were to start from scratch, we'd recommend a 120tpi tire - they're lighter, and offer a smoother ride than 27tpi.
Why should I go tubeless?
We're frequently being asked - why tubeless? Many of the same reasons that you run tubeless on your mountain bike apply just the same, or even more so, to fat bikes.
Low Pressures - no pinching
It's somewhat common knowledge these days that low pressure = greater grip and smoother ride. Typically with mountain bike tires (say, 2.1"-2.5" wide) you'll run anywhere between 22-40psi depending on terrain, riding style, rider weight, and so on. But with fat bikes, pressures range from 2-15psi. If you're running tubes, we typically recommend staying above 6-7psi unless you're riding groomed ski trails or powder.
With that low of pressure, you're running the risk of pinch flats on your tubes if you're riding anything with rocks, roots, or anything rather bumpy. You can always increase the pressure, but in turn that decreases available traction drastically, while also dropping the ride quality and control you gain from your (probably) rigid fatty. No one wants low traction and a rough ride.
In comes tubeless. Just like your mountain bike, ditching those tubes provides you the capacity to drop your pressure much lower without concern of pinching that poor tube - let's be honest, nobody wants to have to change a flat on a fatty because they pinched. That's just too much work.
drop some lbs from your fatty
Up until the past couple of years, you were lucky if you built your fat bike to be sub-30lbs. Nowadays, there's fatties available stock off the line that come in sub-25lbs, and not just a hair under, but often drastically lower (think 23.4lb). Your average fat tube (Surly, Chen-Shin, anything rated for 3.8-5") is heavy. These bad boys weigh in at right around 480g... that's over a pound - per wheel! Dang... And that's before you add sealant to help prevent puncture flats (cactus, goat heads, etc.).
Prior to our switch away from Gorilla Tape to Orange Seal tape for tubeless - our typical fatty tubeless setup would come in at about 280g, dropping almost half the weight of a tube. That's with 1 wrap of Gorilla Tape on the rim, 1 valve, and 8oz of sealant. We recommend using 8oz of sealant on Gorilla-Taped, since Gorilla Tape is a permeable membrane, so it would absorb about 50% of the fluids put into the system. With Orange Seal, the tape is impermeable, and as such we've been recommending 4oz of sealant per tire rather than 8oz.
Okay, maybe he'd just tell you to harden up and ride a single-speed everywhere, but you get the point.
A factor of low pressure that many, including ourselves, frequently overlook - is tube-to-tire friction. It's a thing, and it's a tremendous problem with the low pressures of your fatty.
Think about it for a second - if you're running as low as 25psi in your 2.5" tire, that's a much greater amount of pressure forcing the tube against the tire and holding it there. Now, in your fatty, let's say you've got 5psi pushing that tube against your 5" tire... That's a lot less. Like, practically nothing, arguably.
Now take that tire, load yourself onto the bike with all your cold-weather riding gear, lunch, beer, and perhaps camping gear (if you're into that sort of thing), and start riding it through some white fluffy stuff. Now you're compressing and unloading that tire/tube combination with every rotation of the wheel, rolling over bumps - perhaps rocks and roots, and just constantly causing that tube to flex and rub within the tire. No amount of talcum powder is going to help relieve that much constant friction, in fact, it might just relocate shortly after you start riding and do you no good. Have you ever looked at the inside of your fat tire? That wouldn't be a fun surface to be exposed to continual abrasion on.
If you're using a proper fatbike tube (seriously heavy), the rubber thickness is greater when inflated to 2-15psi than that of a freeride tube (much lighter, but has to expand further), so you'll probably have a little more riding before parts of the tube get worn from abrasion enough to cause you an issue, but in time, it's bound to happen.
This is kind of a moot point to follow up the previous three, but we've been putting sealant in tubes and tubeless systems (not just fat... road, cross, mountain, BMX, etc.) for long enough that we've noticed something...
Sealant simply lasts longer in a tubeless system. We're not sure exactly what it is that causes sealant to dry up in tubes, but in just about every tube out there, there's a fair amount of talcum powder contained inside the tube to help prevent dry rot from the inside-out from moisture content, and I would venture to guess the powder speeds up the congealing process of the sealant.
One other, also pretty minor factor of this - if you've got a tube, you're unable to [easily] remove old, expired, bad, or congealed sealant. Have you ever had your tubeless sealant dry out, only to hear something rattling around inside your tire? That's what we lovingly call a Stan's Coral, a balled up bunch of latex goop that forms as your sealant spashes around and dries out inside your tire. If you've got a tube, that's in there for good. Tubeless? Just pop that ol' bead and remove the coral.
Why tubeless may (or may not) be the way.
Now, these are all the reasons why we think tubeless is the way to go with your fatty. But you're probably not reading this to see only the benefits of converting. That's like converting to the all-chocolate diet because you were told it's the most delicious thing to ever happen to your life since... well, since a moderate intake of chocolate was introduced to you as a child with that very first taste of chocolate ice cream.
One can only dream that everything in life exists simply to benefit you, but that's just not how things work.
You can still get a flat
There's only one guaranteed method to never... ever getting a flat again with your tire (see: here). And let me tell you, I've had to install one of those, with the help of about 5 other mechanics and 16 tire levers - 12 of which broke... they're no fun.
With tubeless, there's no guarantee that you'll not get a flat, you can forget to top off your sealant, burp the tire, tear a sidewall, run over one helluva cactus. You name it, it's probably happened, and probably to one of the guys who are selling you on going tubeless. But let's be honest, whether you ride fat or skinny tires, all of the former possible causes of a flat tire exist on any tire size. Not just fat.
The only draw back to fat tubeless is...
Ginormous tire volume
But let's face it - if you get a flat with or without tubeless, you still have to inflate that huge tire. Trying to inflate one of these bad boys with a hand pump is brutal. But that's a fact of life regardless of the initial presence of a tube in your tire.
If you run tubeless and get a flat, unless you've got some monster CO2 cartridges you're looking to burn through, we don't recommend trying to set it back up as tubeless - the same applies to standard mountain tubeless. Always carry a spare tube (or two) just in case; if you're lucky, you'll never touch 'em, but you'll always be prepared.
Sealant and the environment
We're not going to recommend that you just spill your sealant out trail-side and leave it there. That'd be irresponsible. If you're really prepared, some folks will shove a large zip-lock in their pack and try to soak up the sealant with dirt, then pack it out. You could even toss some kitty-litter in there to help speed that process up.
But in the event that some (or all) of your sealant spews, gushes, or otherwise pours out into nature - fret not (maybe fret a little). Stan's sealant is environmentally-friendly, using natural latex, non-hazardous, non-corrosive and non-toxic ingredients, a little bit of sealant loss won't immediately warrant GreenPeace descending upon you in a fiery rage of environmentalism.
That said, everyone appreciates any and all efforts to containing spillage where possible.
Some rim & Tire combinations are incompatible
It's not fun to say, but there are some rim and tire combinations out there that simply will not work together to form a tubeless system. We have had tremendous success with all Surly fat rims, as the bead seat sidewall is short enough that when properly applying Gorilla or Orange Seal tape, we can mimic the Bead Socket Technology of Stan's rims, effectively giving the tire the tightest tolerances on which the bead can sit. There are some manufacturers of rims out there whose rim sidewalls are simply too tall to hold the bead effectively in the manner necessary, resulting in the bead falling off when deflating the tube after taping.
If you are interested in setting your fatty up tubeless, but are concerned about this compatibility issue, feel free to stop by the shop and ask one of our mechanics. We'll be more than happy to take a look at your rim and let you know if we think it can or can't be done.