First Impression: 616 Fatbike

By Karen Brooks

I’ve been wanting to try one of the latest crop of fatbikes for a while now. I got to ride the Surly Pugsley we tested for Dirt Rag oh so long ago, and it was a lot of fun, as was the Jones Spacebike with its fat front tire.

Now suddenly fatbikes are everywhere, and not just for sand or snow. I’ve seen a few people in my local park riding big huge tires on dry summer days. In fact, with the couple of fatbikes at DRHQ currently, we wanted to test the theory that they’re fun and capable for “normal” conditions. This 616 Fat arrived just in time to get a couple of “normal” rides before the local trails got mired in mud, and then…

Snow.

 

So much for “normal.” We had such a mild winter last year that I think we thought we’d escape again. Anyway—fatbikes are good for snow.

616 gets its name from the area code in its home turf in western Michigan, where folks know a thing or two about harsh winter conditions. The founders of the brand are the two former owners of the Slingshot and Nukeproof companies—an interesting combination of old-school innovation. 616 makes its own frames and offer standard or custom geometry at no extra charge.

It even partners with another Michigan manufacturer to produce its own line of hubs, as well—and they’re injected with Morningstar Soup lubrican t, which is rated from -50 to 140 degrees F. Now that’s cool! What’s the point of a monster fatbike wheel that seizes up in deep cold?

That rear is a 170mm spacing, the front is 135mm. The rims are Snowcat from Alaska, 44mm wide, paired with 45NRTH’s Hüsker Dü tires. I love these tires. They have a good amount of knobs without being ridiculously heavy. Surely I’m not biased because of my love for the band of the same name:

The rims are on the narrow end of the fatbike spectrum, but for my weight and the local conditions, I wouldn’t want to go any wider.  

Tire pressure is crucial with a bike like this. Small differences in air pressure can make the difference between basketball-bouncing, squishing all over the place, and a Goldilocks perfect medium. I started out with 9psi, and have been going with 5.5psi in the front, 6psi in the rear lately. (Yes, that’s low, but keep in mind I weigh 120lbs.) 

 

At pressures this low, it’s necessary to use a digital gauge to get an accurate picture. As you can see, a typical pump gauge doesn’t even register. Fortunately I have an SKS digital gauge that seems to measure these low pressures just fine. I’ve thus far neglected to measure the pressure after a cold ride (10-20 degrees F) to see how it’s affected (PV=NRT and all that), but since the area of my house where this bike is stored is typically below freezing, the difference may not be too much.

(We’re going to experiment with converting the wheels to tubeless later in the week, so stay tuned for a post on that!)

The one really muddy ride I had was interesting. I went on some little-used old moto trails and had a great time, up until the point when the tires picked up a critical mass of half-frozen mud and leaves on the north side of a hill, at which point I experienced a sudden and complete loss of traction. It was pretty cool for a minute, seeing my back tire come around almost perpendicular to the front. Epic drift! But then the front went as well and I went sliding down the hillside, off the trail completely. Apparently one of the few drawbacks of fat tires is that you lose the ability to dig down into the soft stuff.

On the first snow ride, in a heavy, almost sandy 4-5 inches, I found myself wishing for XC skis instead, as it was tough to push the wide tires through the heavy white stuff. But the next day I took out the skis and it was no better. The bike is much happier in the fluffy stuff, which is fortunately what we’ve been getting lately. It’s also awesome over that rock-hard, choppy surface that results from a thaw-and-refreeze cycle, which we’ve also had a couple times in the last month. At times it feels like “hero dirt” with all that rubber to grip it.

Ivan approves, even if he doesn’t like standing around in the cold for photos. It’s tough work, being a model.

The 616 Fat is scheduled to appear in the #169 issue of Dirt Rag, hitting newsstands and mailboxes around April 2. Subscribe now and never miss an issue!