Fat Bike Tubeless
How-to | FAQ
Fat Bike Tubeless
How-to | FAQ
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.
There's lots of variables with fatbike tubeless, here's a few pointers that we've found help out a lot.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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...
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.
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.
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.
Uni-Directional bearings | SRAM Type 2 | Shimano Shadow+
Uni-Directional bearings | SRAM Type 2 | Shimano Shadow+
We deal with the finite details of bicycle functionality on a daily basis, and one day we were wondering... How does a clutched derailleur actually work? We know the principle of their function, a uni-directional bearing rolls to allow the cage to retract with the derailleur's spring tension, and resists the extension as you shift through the gear range, and as the derailleur compensates for suspension-induced chain growth.
The outer race has pressure applied by an adjustable collar on Shimano, which can be engaged and disengaged via external switch, and on SRAM, via conical bearing seat located within the cage pivot. This we knew, but as to how a bearing could only rotate in one direction, and intentionally bind in the other, was new technology to us. Every bearing we deal with spins forward and reverse--suspension, hubs, headsets, you name it... it spins two directions.
With a demo fleet pushing 80 bikes, we see a lot of wrecked rear derailleurs, and have a bin dedicated to smashed derailleurs set aside for spare parts when the opportunity so presents itself. Enter inquiring minds...
Thank you to Renold Technologies for the informative video below, as well as the images shown here. Their video will elaborate much better than I could hope to explain, plus moving visualizations.