What tire pressure for a fat bike?

dgroebl

New Member
I’ve just received my new super sweet Juggernaut Ultra FS fat tire bike and I’m not sure what kind of tire pressure to run. I realize the 26” x 4” fat tires will probably always seem squishy but I wonder what is a good pressure of them. I’ll just be riding on the street as a commuter.
 
I’ve just received my new super sweet Juggernaut Ultra FS fat tire bike and I’m not sure what kind of tire pressure to run. I realize the 26” x 4” fat tires will probably always seem squishy but I wonder what is a good pressure of them. I’ll just be riding on the street as a commuter.
Read the tire pressure recommendation on the Sidewall of your Tires !
 
Sorry, I'm new to the cycling world. In the automotive world at least we don't drive around with the max pressure as labeled on your tire sidewall. Your fuel mileage would be great but your ride would be terrible and wet and dry grip limits would be negatively affected as well.

That being said I was quite shocked to see that the max pressure was only 30 psi! I put them up at 28 after reading Ian's post, but now after seeing Tars post perhaps I'll try 25 and then 20 and see how she feels.
 
26x4 has a lot of square inches of rubber on the ground. Your bike mfgr ought to have something to say about this, but try and adjust until you get comfortable.

TT
 
The best way to find your personal psi is to air up above what you think necessary and ride on your typical surfaces while incrementally letting out pressure and noting the ride characteristics each time. Once the ride quality gets noticeably bad take a psi reading and then pump back in a few psi or until it feels good again. Note that psi on your gauge and use that. If you increase the load you might want to add a little to compensate.
 
I found tire pressure is really about the kind of terrain you're on, and what you're comfortable with. I don't even carry a tire gage in my bag, I just Fill and Chill ! ??
 
I like to ride on the beach so I air down and back up fairly often when I'm there. I find a tire gauge extremely useful. Depending on the sand, I'll air down to 8 pounds or so and back to 20 when I get back on pavement. Without a tire gauge the process would be a good bit more difficult.

And my tires lose about 5 lbs of air a week. I can tolerate that okay, but a gauge makes it easy to air up to 20. I could guess, which I do when I'm pumping air into the tire, but based on my gauge, my guesses can easily be 7 lbs off. That's not killer, but the gauge is so easy, why not use it and get the air where I want it?

TT
 
When I was in AZ for the winter the roads were horrible. I ran 11# in the tire and it smoothed things out a lot. Back home I went to 20#. Felt to hard after running so low before. I have them set at 14# now. I just got use to the smooth ride.
 
Different tires handle differently at different pressures. The Kenda Krusades that came on my RCS were fine around 18-20 psi. The Vee Rubber Speedsters I put on my RCS are a lot quieter and roll easier on paved roads, but get really "squirmy" below 25 psi. I usually run the speedsters around 28-30 psi (2 bar) as a result. More or less the Krusades are loud and cushy. The Speedsters are more efficient and quiet at road riding but not as cushy because they are firmer.
 
Fat tires don't act like road tires. More pressure in not always faster or easier to pedal. I have a non-e fatbike with 26 x 4.6 Terrene Cake Eater tires and am running 10 pounds on pavement and other hard-packed surfaces. I tried higher and it was not any faster, just harsher. I weigh 188 pounds and the bike is around 35. If you have 4" wide, maybe try 15 PSI. As MechaNut said, Different tires handle differently at different pressures. I run over 50 PSI in the 26 x 2.5 Hookworm tires on my 70-pound full-suspension ebike that I use mostly for errands, river shuttles, and commuting. Play around with it - experimentation is fun and free.
 
Depending on the surface being ridden on I have found that for myself with a 26 x 4.8 tires that the following pressures work well:

Asphalt / Hard Surfaces: 21-26PSI
Mountain / Offroad: 12-16PSI
Mud / Snow conditions: 7-9PSI

***NOTE: If you winter ride in colder climates you have to keep in mind that your tire pressure will decrease a few lbs due cold conditions.

hope this helps,


Will
shop.scooteretti.com
 
I ride at 20psi. At 30psi (the recommended maximum), your tire turns into wood and you lose any cushioning. Lower pressures are best reserved for rough terrain, sand and snow.
 
29 PSI,
Because you have the full suspension absorbing every bump and dip.
Soft tires are just that, soft, and susceptible.
Good name the Juggernaut @ 75# ( whoa Nelly ) bike & rider = lots of energy through bike tires.
 
I'm new to fat bikes although in the past I was a sponsored regional MTB racer so take my comments accordingly...also I'm mid 60's, 150 lbs with some health challenges but still ride some crazy terrain and nasty trails.

When my M2S Ultramax HT came in the 4.5" tubed tires were inflated to 20 psi so naturally I tried it around the neighborhood like that. Didn't seem too bad so took it to a groomed snow MTB trailhead where I was advised to lower it to 10 psi. Even that left me with a rounded tire profile on the snow so I dropped it to 5 psi. After a 150+ miles on the snow, I've settled with 5psi in the rear and 4 psi in front for superb traction and handling. If I were to ride those tires on hard ground they would go up about 5 psi more. They would not my choice for summer trails and I also have a pair of 27.5" wheels with 3" tires that are way better suited for that and will probably be run around 12-15 psi. Eventually I will get some smooth tires around 2.5" for summer, which I think will be even better for pavement at 50 psi.

There's no generic answer for how much pressure to run, it depends on your weight, trail conditions, size and construction of your tires as well as riding style, etc.. For a fatbike in snow or soft ground the goal is to have your tire squished completely flat on the bottom. When you run those same tires on the pavement like that they will 'wallow' in the turns, self steer, and they'll feel like crap. Bump it up in psi to round out the contact patch and they will handle somewhat better but be very loud. Fat's are fun but not very confidence inspiring at speeds much over 20 mph and scary at 30 mph...for me.
 
Read the tire pressure recommendation on the Sidewall of your Tires !

Only if the sidewall actually says "Rec" or "Recommended." Otherwise, it is the MAXIMUM safe pressure.


For instance, if you look at a Maxxis Chronicle sidewall it looks like this:

Screen Shot 2020-04-15 at 4.51.05 PM.png


That is the MAXIMUM Tire pressure according to Maxxis's site:

Screen Shot 2020-04-15 at 4.51.48 PM.png



BTW, the OTHER side of the Maxxis Chronicle looks like this:
IMG_6140.jpg


Which says 12-30 PSI. Again, that's the safe range. You need to be in that range (unless you've got some foam insert thing going on), but it's not a recommendation as to which pressure to actually use.
 
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Hi,
I am running 18psi on the front and 20psi on the rear with my 26' x 4' tires for road /bike trail use, I am 170 lbs and my bike is 130 lbs. So 300 lbs. total.
Which seems to be O.K. When you build your own there is no chart to say what pressure to use.
 

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What a difference 1.5" in width makes on a bike, also going from 26" to 27.5"wheels. My M2S Allterrain Ultra HT came with Kenda 4.5" and they were amazing on the groomed snow trails at 4 and 5 PSI. Totally hated them on hard trails and asphalt and even tried airing them up to 15 PSI so I ordered a new wheelset with plus size 27.5" wheels. Absolutely love them for all around use aired up to 13 and 15 PSI. Bonus is that my milage went up to double what I was getting on the fats. A bit harsher on rough trails but not so much that I use my old suspension seatpost, although I may put it on someday rather than leave it collecting dust in my parts box. Wish I knew all this when I ordered the bike, definitely would have been better off for my use with just the 3" tires on 27.5" wheels, of course ymmv.

Tire pressure and ride is such a personal thing it's hard to say what will work for someone as a generalization. We used to spend considerable time pre-riding the race courses while adjusting the pressure a few pounds at a time until we hit the sweet spot. Most of the time several friends and I would end up close to the same pressure but sometimes we were 5-10 psi different and convinced that each of us had the perfect pressure on that course for the conditions...
 
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