Mastodon Pro

I have two Mastodon forks. A first generation—2017–model and a 2021–22 model. Both forks deliver excellent performance. The latest version offers subtle but meaningful improvements including, a lower profile compression knob allowing for better down tube clearance on more frames.
I HIGHLY recommend purchasing the Infinite rate tune kit (IRT) to replace the Incremental volume adjust (IVA), which comes standard on the fork. For the newer versions of the fork, **Be sure** to get the IRT that is installed using a cassette Lockring tool rather than a socket.
The well refined chassis is what sets this fork above others designed for fat tires. Excellent fit and finish, easy wheel installation, straight forward setup and operation, and outstanding customization—especially with the IRT. The functionality of this fork with its ability to either be set up in a way that you almost forget it’s there, because it’s just doing the work of absorbing the bumps. Or, tuned to feel a very specific way that suits a particular style of riding, offers an improvement to any fat bike that cannot be overstated.

Had a Wren, and it was a noodle compared to the Mastadon. The Mastadon is stiff as hell and much easier to tune.

Don't think just buy! Well worth the money!
Far exceed the RS Bluto on performance and stiffness.
I have it on both my fatties and increased travel to 140mm on both. It's turned both of my fatties into year round bikes.
Both are the EXT Pro models it's the only way to go. Now I see Manitou makes it on 150mm, I'll definitely get or 2 in that travel.

Just upgraded my Bluto to this fork, I live in New England and this fork is amazing, currently have only ridden in the snow, but cannot wait for dirt. - I cannot even believe the difference. I put the fork on a Foes Mutz.

I debated whether to switch to a suspension fork on my farley 5. It seemed pricey and I was worried the extra weight might turn into sluggish handling. The Debate is over. This fork completely transformed my fat bike. It’s way more capable and more fun. I ride in rocky New England where there there is typically only deep snow a couple weeks a year. The bike still climbs great no problem with seated pedaling and not too much Bob standing. In virtually all trail situations the Mastodon makes this bike so much better. I’ll be riding my Farley year round now. Very quick turnaround and good communication from Hayes. Absolutely recommended this fork. It will slacken a rigid bike so consider lowering the stem upon installation.