Fat Bike Tubeless?

I started fat biking in the flat smooth singletrack trails of Minneapolis and never thought I’d need to go tubeless. Why bother with the sealant and burping beads, I’d never had a flat. The rolling resistance didn’t seem bad. The Framed branded tires rolled SO much smoother than the crappy Vee Mission tires that we’re on the bike when I got it. Why change what works right?

Well, then we moved to North San Diego County and I got a job where lunch rides in the hills around San Marcos were almost a daily thing. Excited to participate and kind of knowing what trail conditions to expect, I put another pound of air in my tubes and set off for my first lunch ride. The trail was SO much rockier than I expected. I’m not talking rounded river stones either. Blades, spikes, spades and scissors are a better way to describe the rocks in these reddish ribbons of dusty trail. But, none the less, my first ride went off great! No flats, seemed to have a little too many psi’s in there but, good baseline.

Fast forward 6 more lunch rides and I’d had 4 flats, none that left me stranded but rather the ones that would have you finding a flat in the morning.

This section isn’t even that bad!

Not too worried but more annoyed with constantly changing tubes and increasing my pressure until the ride became uncomfortable. Tolerable? Yeah, temporarily, sure.

Knowing I had to do something, I decided to try out the Maxxis Minion FBR that I had ordered for a fat frame build I was planning. I ordered the sealant injector kit and 24″ tubes (split tube tubeless was my best option) and then it finally happened. Bombing down Switchbacks, a great test of a bike, rider and mostly tires! Seemed to be having a good run but then I felt it. Rim to ground! It had finally happened. A snakebite puncture!

Like the good boy scout I never was, I was prepared! I HATE having to walk out of a ride! I was ready for this. Pump and tube in hand, I changed out the tube and continued on my way. The whole rest of the way down the trail I was thinking “5 flats, it’s finally time to go tubeless!”

I read up on the conversion and gave it a go! I had rounded up a length of 3/16″ ID clear poly tube to use from my air compressor to the valve stem and shot some air into the tire! Pop! Right on! I hardly even heard any air leaking between the split tube and the tire. Added 4oz of Slime tubeless sealant that I had gotten at a CX race in MPLS and took it for a spin around the neighborhood. Done. Pumped it up to 10.5 psi (where I ran my tubed Framed tires) and went to bed. Next morning, still reading 10.5!

One of our favorite rides at work is up Switchbacks and right back down it! As challenging as Switchbacks is to go down, it’s just as challenging going up. Steep and technical is the name of the game on this ride! I noticed that the grip in the back was improved! I was climbing areas where I would have slipped out on rock on the old back tire. Bitchin’! On the decent, the rear felt more supple and gripped the turns just enough to be noticably better! Bitchin’! No flats either! Bitchin’!

Rides we’re going well! Tubeless in the back and the old way in the front. No flats for over a week!

Still the front Framed tire.

We ride different trails or link up different trails almost every time we ride. Keeps it fun. Another demanding decent is a trail called Whiptail. Whiptail is as brutal on tires as Switchbacks only faster. Wednesday, we set out, I was riding quick, light, nimble… felt good! Then another rider in our group flatted. He had just switched to tubeless but got a puncture sealant wouldn’t fill. Damn. He wasn’t prepared. Nobody has plugs. He had to hike out. The ride goes on. Not more than 500 yards down the trail, I notice my rear tire is low. Pull off the trail to find this.

Shit!

Sidewall bite! Sealant isn’t stopping it. Crap! I need a plug or I’m walking out too! Lucky for me the leak was slow enough that I could pump it enough that I could ride for a half mile or so then pump back up, half mile, pump, half mile… Made it back to the shop. Rough day for tires in San Marcos!

Got some bacon strips from a local shop and and plugged it right up. It actually had two holes come to find out. No prob, fixed.

🥓 strips!
Mmmmmm

In the mean time, the front Maxxis Minion FBF tire came in along with some highly recommended Orange sealant. Excited to get totally tubeless, I do the swap that night!

The split tube!

Being tubeless in the front I could REALLY feel the suppleness! I mean it was like I had a short travel suspension fork. I wound up putting another pound of air in the tire because it seemed SO soft that I didn’t want it to come off the bead. We were planning the most techincal ride we do and I didn’t want any issues. In the parking lot there was a noticable difference in rolling resistance and on the trail, even with 11 psi front and 12 rear it felt smooth and grippy! Traction was definitely improved!

Just an example of the trail conditions.

While out on the trail I actually felt like I wanted more pressure! Something I had never thought on the old setup. The way the front tire would confirm to the surface had me riding a bit more cautious. Funniest part, is that now having the front properly setup I now REALLY noticed how supple the REAR tire was!

Tubeless is so smooth!

What do I take away from this?

1. Go tubeless as soon as you can! Especially on a fat bike, plus bike or anything!

2. Be prepared for ALL tire failures! Carry plugs, pump, a way to fix larger tears in the tire and even a tube as a fail safe.

3. The brand / type of tire makes a difference in different conditions! I think I could have run a really fast and light tire in Minneapolis but that tire would have gotten destroyed here in San Diego.

4. Pressure is SO key on fat bikes! I knew this but it seems even more important now that I know how different tires and tubes/tubeless setups handle pressure.

I will update this post in a couple weeks if there is anything worth sharing but for now I think I have the right tire setup for the trail conditions here. Tubeless is never anything I was against, just didn’t feel I needed. Well, I’m pleased to admit I was wrong. I am convinced, there are clear advantages to tubeless! You should try it if you haven’t already!

Have fun out there!

Allan 9/19/20

Edit: 10/8/20 VERY pleased to report zero flats! I’ve settled on 11F and 13R! Been having a LOT of fun on this bike and worrying less and less about flats! Such a relief!

If you need a great tire for brutal conditions, Maxxis Minions are the way to go!
FYI