Maxxis Mammoth Review: Two months in Mongolia

We took the Maxxis Mammoth fat bike tire on a two month trip around Mongolia. Given that durability is as important as performance on an overseas, backcountry trip – particularly where spares are in short supply – here’s how it fared…

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There’s no doubt about it. However ridiculous it may seem to traditional cycle tourists, extended journeys by fat bike are gaining in popularity. And by extended, I mean multi-month, even pan-continental odysseys. Despite their asphalt shortcomings, it’s little wonder why – nothing can match a fat bike as a tool for off grid exploration.

  • Maxxis Mammoth Review
  • Maxxis Mammoth Review

Maxxis Mammoth Review

Given the surge in omniterra popularity over the last year, there’s a growing pool of excellent tires for sand, snow and aggressive trail riding. But choices have always been more limited for touring, with Surly’s Knard and Larry providing the go-to choices in the past.

Released at the same time as their highly praised Chronicle 29+, Maxxis’ Mammoth wasn’t necessarily designed as a travel tire, but it’s low profile, chevron tread drew me towards it – given the mixed conditions I was expecting in Mongolia. In terms of spec, it’s considered to measure up as a true 4in tire, unlike some that fall short. Weight is just under 1300g; not as light as some, but also somewhat reassuring, given my touring-tinted glasses.

Maxxis Mammoth Review

I ran mine tubeless throughout; losing heavy inner tubes makes for a more supple tire and improves the way it rides, while allowing for lower tire pressures when terrain demands. It also saves time patching flats, which is an especially long winded process, given how awkward fat tires can be to seat. Although there’s a Tubeless Ready version now, mine where the standard 120 tpi EXO ones. Still, they mounted up relatively easily on Surly’s Marge Lite rims, using the tried and tested ‘split tube’ method – even in a garage in Ulaanbaatar, with my Lezyne micro pump, a few extra hands and some concerted arm pumping. I used 24in tubes for a tight fit, and drilled my rims for Shraeder valves. With the core removed, this allows for maximum air intake.

Maxxis Mammoth Review

As anyone with experience on a fat bike will know only too well, tire pressure is paramount. On a long distance tour, it’s probably worth mentioning that you can forget mini pumps – invest in a model with a larger barrel, like a Lezyne Micro Floor Drive HV or a Topeak Mountain Morph – as you’ll be doing a lot of tire pressure tweaking.

Onto performance then. When riding pavement, I noticed the Mammoths have a propensity to ‘auto steer’- where the tire tries to tell you where to go. A trait common to fat bikes, this is most likely compounded due to the Mammoths relatively square profile. Take the time to really air them up though (max psi is 30), and they lose their ego and let you decide. What’s more, they roll surprisingly well – enough that I begrudged pavement stretches far less than in the past.

They rolled similarly well over packed dirt roads, and made short work of rough jeep tracks and tufty Mongolian steppe, which formed the bulk of our terrain. Leant into corners, their raised side knobs helped provide a little extra confidence. When it came to hitting longer stretches of sand, which we experienced on a few occasions, they allowed me to comfortably outride the midfat bikes in our group. This said, they’ve come up short in the sandy arroyos of New Mexico compared to the knobblier tires I’ve tried; their low profile tread means they don’t bite nearly as deeply. Same goes with snow. I’ve had mixed success with them. They don’t pack up, but they loose traction pretty easily too.

  • Maxxis Mammoth Review
  • Maxxis Mammoth Review


For the ‘expedition’ cyclist though, longevity is as important as performance. Here, the Mammoths fared particularly well. I’d estimate I’ve put well over a couple of thousand miles on them – including 2 months in Mongolia, and mountain biking in the UK and the US. Given this, I’d consider the lack of wear to be especially impressive. It’s only since riding the sharper, rocky trails in New Mexico that the side knobs have taken a beating. Still, there’s plenty of tread left for a good more many miles of riding – the images above show its current condition, 6 months after fitting them. Just as importantly – and despite repeated scuffing – I’ve had no sidewall cuts to report either, thanks to the Mammoth’s beefy EXO casing.

Wrap Up

True to its namesake, the Mammoth is undoubtedly tough enough to handle bikepacking in the wilder parts of our planet. Sidewalls are reassuringly stout. The tire handles load well. And once aired up, it rolls along nicely over graded surfaces – and even makes short work of those dastardly stretches of pavement you’re likely to encounter on any long tour. In terms of more extreme conditions, the Mammoth will help you out in sand and snow, but it definitely struggles compared to a more knobbly tire. All in all, I’d consider it a very capable general purpose option, and a solid choice for your next ‘Big Fat Trip’.

  • MODEL NAMEMammoth 26x4in 120 tpi EXO
  • WEIGHT1,290g
  • PRICE $120
  • CONTACT Maxxis

Maxxis Mammoth Review

  • mikeetheviking

    I’ve had good luck with my Maxxis chronicles 120 tpi EXO, Going 6 months strong on them…Zero flats with orange seal. Hey Cass, that’s a mighty big stem bag you have there!

  • Cass Gilbert

    Jay took a set of Chronicles with him. And I’ve had a fair bit of experience with them since getting back. Love those tires.

    Nice looking KK toter! My stem bag is actually a Porcelain Rocket DSLR Singler. Hence gargantuan size.

  • mikeetheviking

    Yeah buddy, I stole the genius (KK) idea from Nicholas Carmen . I found a small bucket in a dumspster and sliced it up … It’s much more secure than I thought it would be, however I made this 2 days ago and I have zero miles of abuse on it:) I was stoked to see the Tumbleweed crew rocking this set up in Mongolia as well.
    I think a set of Revelate/Voile straps would really help tighten things down

  • Andy Long

    Is that a Pugsley or what? I’m really looking at doing a 29+ build and I’m trying to figure out what my frame options are.

  • Mark

    Bike pictured in the article is a Tumbleweed.

  • Cass Gilbert

    As Mark says, it’s a Tumbleweed. This was a proto frame. Production models are due out in a few months, I believe. You can set it up with derailleurs if you’re planning on 29+, but you’ll a 135mm Rohloff hub if you want to run 4in tires.

    Lots of options out there… some of the more bikepacking-friendly options to look at include the Surly Krampus, Surly ECR, Chumba Ursa 29+ and Salsa Deadwood. Lots of fat bikes these days have clearances for 29+ too.

  • Andy Long

    Terrific thanks for that! I’ll keep my eyes on those Tumbleweed frames when they roll out this year :)

  • Cass Gilbert

    It’s a great frame – and the eccentric BB offers lots of versatility in terms of wheel sizes/types of riding. I really enjoyed riding it on bikepacking trips, family tours, and mtb day rides.

  • Bryan Young

    I know tires for touring can become a heated debate… It’s just a question. I toured from Montana to Arizona on a 29er, loved it. I am now building a Surly ECR 29er+; would it be a bad idea to convert to tubeless for an around the world trip?

  • Jason

    Assuming that bike has a BB shell larger than 73mm, how did you go about fitting the XT cranks? Spindle modification? If so, curious what approach you took.

  • Jason

    Ah, it is a 73mm shell…just found the Tumbleweed site.

  • Christian

    The Mammoths got a really bad review here:
    Really bad rolling resistance. The review does, however, mention that it seems like a strong tire.

    If I want to set up the Mammoths ghetto tubeless on Marge Lites, will it differ much to have the TR model? Seems difficult to source in Europe.

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