Upgrade to Fat MTB Tires

Tire Reviews

There’s no shortage of debate about which tires are best suited to distinct types of mountain bike disciplines. The tires you ride are the main contact point with the ground beneath you and they need to be right. Otherwise, contact and control will be poor, and nobody wants a low-quality ride.fat bike

I’ve seen forum comments where people have talked about how they’re going to upgrade to fat mtb tires as they search for ways to improve their ride but many of these comments don’t mention whether fatter tires will actually work with the wheels they have on their bikes. So, before we dive into getting a new set of tires, let’s look at the rims that hold the tires.

Most rims are made from alloy but if you’re able to raise the price you’re willing to pay; you can get a set of carbon fibre hoops. A quick search just turned up a set for $615.

What Type of Rim?

It’s essential that your rims match the type of riding you do. If you use what came with your bike for the wrong type of riding or spend your money on lighter XC rims when you ride only rock gardens and downhill, you may end up with rims resembling a Taco shell. To counter that, a strong set of downhill rims are heavy, and you will have to work harder at pedaling if you ride other than downhill trails.Taco Wheel

Rim Diameter

The three standard MTB wheel sizes are 26”, 27.5” and 29” although Street and Dirt Jump riders often use 24” wheels. Know too that a bike made for 26” wheels can’t upgrade to 27.5”.


Narrow, 23mm lightweight rims are used for XC, marathon and typical off-road riding.

Tougher and wider rims are necessary for gravity-orientated trails.

In recent years 23mm has become accepted as a standard rim width for XC and trail riding, usually matched with tyres up to 2.1” wide. More extreme AM or Enduro riders who frequently ride rock gardens and technical trail features favour 28mm rims with 2.25” to 2.4” tyres.

Downhill and Free-Riders may select rims of 36-40mm or wider, with the possibility of using heavy and reinforced 2.5”-2.7” tyres.

Look at the info graphic below to get some ideas of which rims work with which tires. The data is based on European standards defined by ETRTO.


Filled boxes designate compatibility while also providing optimal tire profile and performance. Dots indicate less ideal performance but are still within the range of compatibility. Empty boxes designate a tire and rim pairing that is not suggested and should not be used.

Wheel Rim / Tire Chart

If you are considering buying new rims and do not have disc brakes, be sure to look for ‘disc’ or ‘disc only’ labels. These won’t be compatible with V-brakes. If you can’t see a label, always ask before buying.


Mounting a tire on a rim not made for the tire will produce some obvious if not disastrous results. If a tire is too wide for the rim the tire shape becomes too tall and round, like a lollipop or light bulb. This makes it floppy at the top because the casing is constricted. This can result in poor cornering performance and tire squirm.

If a tire is too narrow for the rim it can get a square profile. The result is a more exposed sidewall, which can be prone to cuts. Poor cornering becomes a concern because the tire profile is squared off, making a tougher transition to the cornering knobs on the tire. The tire can also lose its damping characteristics if it becomes too square and will return a bumpy ride.

Too wide or too narrow are equally bad so take the time to get it right and refer to the info graphic.


I’m currently riding a mix of tires from two manufacturers and after some trail and more trail, this works perfectly on my typical trails. Like all aspects of bike setup, you need to fully consider your typical terrain and source your tires accordingly. For sure, you won’t be short on choice although it is true that some are better than others and you do get what you pay for.

If you too go out of area often, you may even need to invest in more than one set of tires.

Look at this video, just one manufacturer, so much choice.

Maxxis 2020 MTB Tyre Range | CRC |

My “Go To” for tires is Chain Reaction Cycles because they have great customer service, a 365 day returns policy and remarkable offers year-round. At this time of year, they are gearing up for Black Friday with new offers every Thursday so, it’s worth taking a look.

If you decide to buy from CRC, I will receive a small commission but the price you pay is always as advertised. If you want to read the small print, click on “Affiliate Links” in the main menu.

Comments and Questions

If you need help with tires and rims, please ask and I guarantee a quick response.

Just Ride Hard, Ride Fair, Nobody Hurt

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6 thoughts on “Upgrade to Fat MTB Tires

  1. I am not going to lie, I know nothing about tires.  The bike I own has the same ones on it as the day I purchased it.  This was very insightful and told me a lot of things that I didn’t know.  I also like your imagery in this.  The only thing I would give advice on is maybe to make your headers a little more interesting.  Add to the one word titles.  Keep it up!

    1. Hi Annie, thank you for your comments. Many people are riding with the tires that came with their bikes and, if they work, why change anything unless they’re worn out? I see your point about the short headers and I will be checking them in my next post. Best regards, Steve C

  2. Thanks for this article on the preferences for MTB tires. I would agree that the tire should fit the rim. If you are using a single rim you would be buying tires that fit into it as recommended by the bicycle’s design. The only choice would be what brand to use. 

    I like the concern for the performance and safety. The rider should enjoy the ride and if possible safe from accident due to wrong tire selection and fitting.

    1. Great comments, thank you Abagatan. Performance and Safety are paramount as far as tires are concerned. There’s nothing worse than the wrong tire in the wrong conditions. Poor contact almost always leads to a poor ride. Best regards, Steve C

  3. This is a very informative article. I am not a biker. I have a bike, but I wouldn’t call myself a biker. The different tires that you explained and their use made so much sense. I bought a bike several years ago, but after a while, the handlebars just kept getting looser and looser. Many times while riding the handlebars would just flip forward. I tried tightening them on numerous occasions. my husband tried tightening them, but the just didn’t seem to want to be tightened. I think it was a defect. That could be why it was returned to the store and why they sold it to me at a discount. Of course, the store wouldn’t tell you that kind of information. I went to several different bike shops to inquire about what to do and how much they’d charge to fix my bike. They all charged more than what I paid for the bike itself. Unfortunately, I just gave up. I rode for a time with the temporary fixes that my bike allowed before its neck did the swan dive again. However, eventually, I just stopped riding.

    When the bike and I were able to enjoy our rides together I rode on the city streets and through state parks. I think my bike is a mountain bike. It’s an “X” something. I have forgotten now, it’s been so long. I know that it has the thick tires like in the pic above. It was great on the downhills, but a bit tough on the uphills. I had no idea that tires on a bike were important to consider when buying a bike. Although, I do realize that if someone wanted to do Dirt Bike Racing, for example, then the right bike and tires would be important in that case. But for everyday (recreational) use, I figured it didn’t matter. This article makes things very clear. I will probably sell my bike to someone who is handy and knows about bikes since I will be moving out of state soon. If I decide to buy another bike down the road I will be much more informed as to what to look for. Thank you for this article.

    1. Hi Lana, Thank you for your comments and particularly for outlining the problems you’ve had with your bike. This is definitely helpful to other riders. I mentioned this very problem in a post a while back and referred to such bikes as BSO’s . . . bike shaped objects. Much has been written about these and they are typically sold in large stores like Walmart, ASDA (UK) . . . The “swan-diving” handlebars has been particularly mentioned. If you do decide to buy another bike, always drop me a message, I would be happy to help out. Best regards and happy moving, Steve C

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