Everyone that has been asking for a stiffer fat bike suspension fork, your answer is here. Teased at the Taipei show, the Manitou Mastodon made its debut at Sea Otter and it’s nearly everything you could ask for. Not only does Manitou claim that it’s the stiffest fork on the market, they also say it will fit every fat bike tire size out there along with 29+. Add in the ability to run truly long travel and keep the performance at any temperature, and you have the makings of a great suspension fork for the fat bike crowd…


Thanks to the crazy proliferation of tire and rim sizes when it comes to fat bikes, the Mastodon had to fit a lot of different options while keeping stiffness to a high degree. Because of that, the fork uses 34mm stanchions which allow the fork to offer up to 150mm of travel. Tire clearance is rated to 26 x 5.15″ or 27.5 x 4.5″ which means the fork will clear every tire on the market including the Vee Tire Co. Snowshoe XXL.

To do so, there are two ride height configurations – standard and EXT or extended. In standard mode, the fork has many of the same measurements as the Rock Shox Bluto including the same ride height. To fit even larger tires though, the fork has an extended mode that increases the ride height in order to clear the biggest tires at bottom out. Based on the charts above, you can figure out what setting you would need based on the tire you plan to run.

Update: We wanted a little more information on the difference between the standard and EXT version, especially when it comes to travel adjusting. Manitou has confirmed that you can convert between the standard and EXT version of the fork, but additional spacers may need to be purchased depending on which way you’re going. Manitou recommends starting with the overall tire diameter to determine the base model fork, from there you can adjust travel and ride height to best fit your needs. For any given travel, the EXT forks will have an additional 20mm in ride height. Both forks can be adjusted in travel from 80mm to 140mm, the 150mm travel fork is a separate Pro only OE fork. Also note that the EXT 26 can fit a 5.15″ tire while the EXT 27.5 goes up to a 4.5″ tire.

More than just fitting larger tires and offering more travel, Manitou wanted the Mastodon to offer a higher level of stiffness for heavier riders or those really pushing the fork. The lowers might not have the most picturesque form, but you can’t argue with the results. Manitou claims the Mastodon is 26% stiffer fore-aft as well as 25% stiffer torsionally. Equally important is the fork’s performance in cold weather – something Hayes/Manitou knows a thing or two about thanks to their background in snow sports as well as their location in Milwaukee. Thanks to improved seals, the Mastodon claims to have lower friction across every temperature range, both dynamic and static, though the biggest gains come at lower temperatures. Keeping with current standards, the Mastodon uses a 15 x 150mm tooled thru axle.

Mastodon Pro Spec:

Mastodon Comp Spec:

Available in Comp and Pro models, the Pro Model upgrades the fork to a Dorado Air spring, adds high and low speed damping adjustment from a new MC2 derived damper, and takes out 220g from the total weight. Both forks are also compatible with their IRT Infinite Rate Tune kit upgrade which allowsmore control of the mid-stroke rate independent of the bottom out.


The Mastodon was one of the forks undergoing extensive testing during our recent trip with Hayes to North Carolina, and it was pretty clear after watching Phil shred Bailey Bike park on the fork, that it’s not your typical fat bike fork. More impressive was that he was riding out there on the Comp model rather than the Pro which he said was noticeably better.

Since the fork is able to run up to 150mm of travel, it enables bikes like the Foes Mutz which features 150mm front and rear. Sold in 26″ and 27.5″ 100 or 120mm platforms in both Comp and Pro, the forks start at $649 for the Comp version and $849 for the Pro.

Changing gears entirely, the Markhor is a new Manitou suspension fork that is on the other end of the spectrum. Starting at just $249, the Markhor is a TS Air fork available in 26″, 27/5″, 27.5″ Boost, 29″, and 29″ Boost versions with 100mm of travel, 9mm or 15mm thru axles, adjustable rebound, and a lock out.


  1. Jared Sahagun on

    Hi. Does the reverse Arch ever contact the down tube when fully compressed? This is my only concern and already putting my pennies aside for this fork.

  2. jednobiegowiec on


    Never had anything like that Jared.

    Big fan of Manitou forks, looking forward to have it 🙂

    Bring Mastodon in!!!


  3. Manitou_nc on

    @Jared Sahagun. For the Standard Mastodon, at full compression the arch is 4mm lower than the top of the crown (crown race seat). Naturally, you’ll have some addtional head-set stack heaight and down-tube clearance at the down-tube junction in addition to this 4mm. If you run the Extended mastodon you’ll have clearance for days.

  4. Sean on

    The tire clearance chart doesn’t make sense to me when comparing certain tires and comparing STD to EXT models. The chart says the STD cannot clear a Dillinger 5 but will clear a Bud or Lou? Bud and Lou have WAY more volume than D5.

    STD can’t clear a Knard 3.8 but can clear a Knard 4.8?

    Maybe I’m reading something wrong but those examples seem at odds with each other.


COMMENT HERE: (For best results, log in through Wordpress or your social media account. Anonymous/fake email comments may be unapproved or deleted. ALL first-time commenter's posts are held for moderation. Check our Comment Policy for full details.)

This site uses Akismet to reduce spam. Learn how your comment data is processed.