I know most of you are familiar with the tire and tubes of the more traditional bikes but confused about the fat bike tires sizes.
But it’s not hard as you’d think.
Generally, fat tires range from 3.7″ to 5.2″ and are usually mounted to wider rims measuring 50mm to 100mm.
The volume range between fat bike tires can be huge, with the narrow tires ideal for the groomed snow parks and desert tracks. On the other hand, the wider fat tires are ideal for heavier, unpacked fresh snow & more rugged terrain.
Either way, understand fat bike tires size isn’t simply about the choice of terrain. A fat bike is only as good as its tires.
The difference between the right and quality fat bike size makes a difference when the rubber meets the road.
However, a good fat bike costs a fortune, particularly if you want the options with studs.
Having said that, I’ll share everything you need to know about selecting the fat bike tire size in the section below.
Fat Bike Sizes
As their name suggests, fat bikes have bigger tires. And we’re not talking about 2” or 3” tires. No, we’re referring to 3.7” + tires and above. It can go up to 6” +.
That’s about twice the size of the typical mountain bike tire or nearly four times the tire width of your typical road bike tire.
The wider width and diameter of the fat bikes tires work well for winter riding on rougher surfaces. It can take on the sand and rocky & rough terrains, too.
The versatility of these fat bike tires doesn’t end there because they are also ideal for groomed snow riding and will navigate through the snow and ice.
The wider surface provides a large surface area to prevent the tires from sinking. At the same time, the wide tires have extra tread to keep the tire from slipping on the frozen surfaces.
So, if your idea of fat biking is taking on different and challenging terrains, I would recommend a fat bike tire.
The fat tires do the donkey work and are more efficient at low tire pressure.
They also provide more cushion for your ride. While they can’t really replace a suspension system, the fat bike wheels absorb much of the shock and impact from your ride.
And in any case, since the fat bikes are specially designed for use on sand and snow, suspension only comes in handy for special occasions.
In theory, though, it’s still advisable to have some front suspension forks since the bike can take on some pretty big hits. But with good bike handling skills, it’s easier to get away with a rigid bike frame.
However, because of their size and everything, the fat tire requires more effort. But that’s not a big problem because there’s a price to pay for every tire design.
The first step to selecting the right fat bike tire is the tire size.
Most fat bike riders would think that the fattest tires are the best options, but they are far from it.
In my opinion, the best size for your fat tire should fit your frame but, more importantly, align to your riding terrain.
But, if you’re unsure of what size will work for you and plan on mostly off-road navigation on sand or snow, I’d recommend you go bigger.
With that said, here’s a general guide that should help with the tire size selection:
The 4.0-inch tires should suffice for the summer dry trails and groomed snow riding. Or rather, if you plan to ride the same trails as you would on any other mountain bike, anything within or lesser than 4 inches should suffice.
The 4″ tires are also a great choice for UK summer riding and hardpack snow. Of course, they’ll come up short against the bigger tires in the really deep sand and snow.
Personally, I’ve had a 3.8″ tires, and I loved them. But now, I’ve a Giant Fattie with 4.8” and love the tires even more, even when using them on the normal forest trails.
As I mentioned earlier, the bigger tires have a big advantage over the really deep snow and sand. Plus, they require low tire pressure and cover more surface area for greater stability.
Of course, there’s a price for the bigger and wide tires. The penalty for these tires is greatest when doing climbs and when making the steep trails.
However, if you live in flatland or ride in sandy areas like Florida, it’s easy to justify the bigger tires.
But if you do lots of mountain cycling and have to ride uphill miles after miles, it’s easy to notice the few extra grams.
The good thing with going big is if your bike frame allows, you can always back it off a bit.
Personally, my 4.8” have served me well, and they seem like the perfect size for all year round.
But others would disagree, and I’m fine with that. See, the size is really a personal thing. You’ve to try a couple of options to see what works for you best.
Either way, I like the fat bike tires because they allow me to flex between a couple of different terrains.
The fatties are versatile and will excel on the hardpack trails, groomed gravel trails, adventure roads, or even down hilling.
But more importantly, they give me an edge over my mountain bike once things get mucky, snowy, slippery, muddy, and leaf choked.
The next element to pay attention when choosing a fat bike tire is the tread pattern.
As with normal bikes, fat bikes also come with different tread patterns.
Generally, tread for fat bike tires is classified into two; slick and knobby tires.
If you’re navigating the paved surfaces, I’d recommend a fat bike tire with slick tread for low rolling resistance.
On the other hand, if you’re heading out on the rocky and rugged terrains, I’d recommend a knobby and more industrial-looking tread. The knobby tires can withstand the harsh and rough terrain.
Now, let’s go into detail about each tread pattern below.
Most fat bikes ride on tall, thick, and widely-spaced knobs. These knobs provide more surface contact with the ground and so better grip.
The knobs dig into the soft surface much better, providing more stability and maximum traction.
But there’s a price to pay for the traction. Speed and traction work in opposition, so the knobby tires’ security and stability come at the expense of speed and faster rolling efficiency.
Conversely, if you’re riding your fat bike on the relatively hard and packed hard ground, you won’t need as much traction and grip.
Use the slick tire with less tread pattern. The slick tires are ultra-smooth and ideal for winter riding the hardest surfaces and on ice.
The slick surfaces don’t offer much traction to the smooth surfaces, which you don’t need anyways, but provide less rolling resistance.
See, the slick tire has less contact with the road, so there’s less friction. Simply put, it’s easier to achieve higher speed and greater acceleration on the smoother tires.
But then, we’ve a middle ground, somewhere in between the hard-packed snow and the ice. For such conditions, I’d recommend fat bike tires with small knobs.
They add some grip to your ride without increasing your rolling resistance from the heavy and slow-rolling studs.
Weight and Construction
The weight and casing for fat bike tires is yet another crucial consideration.
Generally, fat bikes tires are bulkier than normal bike tires.
The heavier weight means they’re generally slow because they need much effort to pedal and get going.
Now, if you like riding at a reasonable pace, I’d suggest you find lightweight tires. You can try some 60mm tubeless rim and 3.8″ summer tires. Best of both worlds. A lightweight monster truck with superb off-road traction.
While the lightweight fat bike tire is awesome for all-around mountain biking, they aren’t really my first choice for the technical and chunky trail.
But either way, understand that speed isn’t on a fat bike’s genes. Regardless of how your tire goes lightweight, understand that it can never match a mountain bike or cruiser bike in terms of speed.
But that’s how it’s built.
In one area though a fat bike that has a speed advantage over other bikes in the snow. Most adventure, off-road, and mountain bikes will struggle over the snow, but a fattie will track smoothly.
The reason is pretty logical; the fat bike tires are wider for better grip, handling, and easier control.
Studs are the small metal points that bolster the overall traction on the slick, glassy ice.
However, depending on the type of terrain, the importance of studs might also be harmful.
For example, if you mostly cycle on the pavement and tarmac, you’ll notice a distinct popcorn-popping sound that sucks your energy and may even tear free from the tires.
However, they play an important role in keeping your fat bike in control while drastically improving the traction on extremely slippery surfaces.
The studs also come in handy for winter fat biking on the icy streets and loose conditions & snow. They’re a handy addition that will keep you from sliding or anything.
Unfortunately, the extra construction material and labor for manufacturing the studded tire bumps the price. These tires are really expensive, with most starting at around $200 each.
The good news is that it’s a price worth paying, especially when snow and ice are present. Expect minimal tire wear and longevity.
Plus, most brands offer the same tire with and without the studs.
Rims carry as much weight as the tire, and their importance can’t be overlooked.
Here’s everything to know about fat bike rims.
The ideal fat bike rim width should align with your riding purpose.
Generally, most fat bike rims are within the 50 mm to 100 mm range.
As with the tires, a narrower rim width has more practical use in soft and more forgiving conditions. The narrower rims are also nimble, especially on general and all-terrain bikes.
Conversely, the wider rim has a useful role when navigating the harder and more challenging terrains in the backcountry.
Construction & Weight
Next to the size, the other crucial factor to consider for a fat bike rim is the construction.
Most bikes feature aluminum rims for strength and lightness. But an increasing number of new bikes have hybrid rim construction, spotting weight-saving cutouts along the rim’s center.
But on the higher end of the fat bike rims, we’ve wide carbon-based rims. These are super expensive, but they shove a considerable amount of weight from the bike. It’s especially true when paired with tubeless tires.
Everything to Know About Tubeless Technology
Tubeless-ready tires are increasingly becoming popular on fat bikes.
While most bikes with tubes installed, a few fat bikes are starting to incorporate tubeless technology in their setup.
But is a tubeless wheel really necessary?
Yes, it’s crucial, and I’d suggest not to believe people who brush off the need for one.
See, some users argue that suspension isn’t necessary on a fat bike. But if you’ve ridden on a post-holed snowy trail on a rigid fat bike, you know how bone-jarring the experience is.
While the tubeless wheels won’t really save you from the shocks, they make a huge difference in the level of comfort. Far much different than any other type of wheel.
See, if your idea of cycling is doing lots of desert riding, mountain biking on the backcountry roads, and bushwhacking, the tubeless tires are handy tools.
The greatest benefits of this new tire are resisting punctures, lowering the total wheel size weight for less rider fatigue, and improving the overall rolling efficiency.
Of course, if your navigation area doesn’t pose much puncture risk, it’s easy to brush off the need for a tubeless tire, but the improved efficiency is still a strong consideration.
But keep in mind tubeless wheels won’t protect your rims. They may save you from pinch flats on the fat bike wheels but won’t protect your rims from crumbling when you take on the big hits.
That said, the tubeless wheels are ultra-light, and it’s not a surprise they’re becoming popular with the fat bike racers.
The tubeless wheels are particularly an incredible asset when used along with the carbon rims. Fat bike racers appreciate the nimble ride while still having the ability to navigate through treacherous, off-road terrains.
What to Look for in Fat Bike Tires
Here’s everything to look for in a fat tire;
Fat Bike Tire Width
Generally, wide tires have better floatation and more cushiness than narrower tires.
However, the corresponding increase in size brings additional weight and greater rolling resistance.
So, while a 5” fat bike tire will have better cushioning and maximum floatation on the snow than the 4” fat bike wheel, it’ll inevitably feel much slower.
The good news is whatever model you choose to go with, you can always use a tubeless setup, which allows running on low pressures on reduces the chances of pinch flats.
Most mountain bikers consider the tubeless tires to resist puncture and improve the rolling resistance.
The wheel diameter is increasingly revolving with time.
Traditional models use 26” diameter wheels, while the new bikes use 27.5”.
Although a 27.5 fat bike is versatile and can still accommodate the 26″, the interchange also means new wheels.
In my opinion, I’d recommend you stick to the manufacturer’s manual. After all, the interchange isn’t simply about swapping the tires.
Seasonal and Terrain Factors
The final selection criteria are the type of riding you often do or the season you mostly ride. It makes a huge impact on your fat bike tire choice.
One thing to keep in mind is even with all the versatility of a fattie; there’s not really a one-size-fits-all for your fat bike tire.
If you need a fat bike for the loose snow or groomed snow trails, I’d suggest you pick tires that can accommodate studs.
Conversely, if you need tires for riding the beach, studs may not be as important as the floatation.
And finally, if you simply need a tire that will double up as a cruiser bike or mountain bike for navigating the gravel roads and loose conditions & debris, choose a tamer, narrower tire.
Fat Bike Tire Pressure
The best way to get the most out of your fat bike tire is by experimenting with the tire pressures.
Unlike other metrics, which are rigid, it’s easy to dial in the performance of your tire by adjusting the pressure.
Lower pressure makes a fat bike fun, at least that for me.
When I’m in the softest conditions, I dial down to lower pressures of just 2psi to get the increased traction I want.
But once I get on the firmer and rougher ground, I dial up the pressure to something like 8psi. Higher pressure increases my sidewall support while bettering my bike’s handling.
Higher pressures are also necessary when I need to increase my pace and save my rims from the big hits.
Always Pack a Pump
Depending on your terrain, you might need to change the tire pressure over the course you’re your ride, so it’s a good idea to carry a pump with you.
On many rides, adjusting the fat tire pressure may drastically influence the floatation, traction, and suspension.
Along with the good mini pump, bring a digital tire gauge to make it easy to understand your specific bike setup.
Fat Bikes Tire Size Frequently Asked Questions (FAQs)
Q: Can I use my fat bike on the road?
A: Yes, you can use your fattie on the road.
However, fat bikes aren’t designed for road use, so you’ll have to live with several compromises, such as speed.
The fat bikes are, however, ideal for relaxing weekend bike rides.
Q: Can I use my fat bike as my everyday bike?
A: Yes, a fat bike is a nice everyday bike, especially if you don’t have to rack up miles or need speed.
The wide tires are safer, comfortable, and plush. They’re also easier to control on your back between home and work.
Q: What’s the main advantage of fat tires on the pavement?
A: Some of the benefits of the fat tires on the tarmac are better stability, safer ride, nice handling, and more comfort from the low-pressure wheels.
Q: Are tubeless fat tires necessary?
A: They’re unnecessary, especially if you don’t care much about speed; you can choose tires with an inner tube. But if you need to increase your cycling pace and save your electric bike watt, they’re an important update.
Q: What is the ideal PSI on my fat tire?
A: The fat tire air pressure will depend on the terrain and riding conditions.
But generally, fat bike tires work best at low pressure, but this is because fat bikes navigate the rugged off-road terrains.
The ideal pressure for loose conditions & snow and other soft conditions is between 4 to 6 psi. On the other hand, the ideal pressure for the firmer ground, such as gravel, may go as high as 15 psi.
Q: Are studs on my fat tire necessary?
A: The usefulness of studs on your tires will mostly depend on the riding terrain.
I’d recommend choosing studs when you’ve to navigate areas you can’t afford to slip, such as icy roads on traffic or mountain cliffs.
However, the 4″ tire width is sufficient for most riders to provide the necessary grip, even on flat surfaces.
Remember that studs also increase the rolling resistance, so it’ll be harder to gain pace.
Q: What are the benefits of fat bikes?
A: There’re numerous reasons why I’d recommend a fat bike tire, but the biggest and the main one is probably the versatility.
Fat bikes can handle various terrains starting from gravel trails, mountain trails, sand, and snow.
However, they excel most in the loose sand and unpacked snow where other adventure bikes, such as mountain bikes, come short.
The wider tires gobble up the gaps & crevices and will run over the obstacles and debris with relative ease.
But more importantly, the wider tires have a greater contact surface with the ground, so they’ll keep you from slipping or anything.
Of course, there are a couple of compromises, such as increased rolling resistance and lower speed.
We’ve come to the end of our fat tire bike size guide.
And as you’ve seen, there’s an element to consider when selecting the ideal fat tire size and the right tire for your ride.
The good news is once you know what size you need for your riding style, fat biking will get effortless and more pleasant.
Share what you think about the fat tire sizes and what size you use in the comment section below.