Fat tire pressure


August 26, 2016, 06:52 AM

I am a fledgling fat biker who finally got a fat bike that I am setting up for some winter rides.  Yesterday I set up the Jumbo Jim 4" tires tubeless but I am not sure what kind of pressures I should run.  I weigh 140 with all my gear and when I tried (I just guessed) 9 lbs in the rear and 8 in the front it seemed kind of bouncy on the road.

What are some of the typical pressures that you guys have been using?

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XXX
imwjl
Pleasant View Trail Steward

August 26, 2016, 11:18 AM

I am a fledgling fat biker who finally got a fat bike that I am setting up for some winter rides.  Yesterday I set up the Jumbo Jim 4" tires tubeless but I am not sure what kind of pressures I should run.  I weigh 140 with all my gear and when I tried (I just guessed) 9 lbs in the rear and 8 in the front it seemed kind of bouncy on the road.

What are some of the typical pressures that you guys have been using?

You should not use road riding to judge the right pressure unless you fill them up to a relatively high pressure for road ride setup.

I'm not too experienced but found what's right varies by tire and terrain. In winter I'm closer to 5 psi and summer closer to 10. If it's fat bike on a road or gravel trail I go 12-15 psi to stop too much bounce.

For summer and rocky riding I try to replicate what won't be a rim hit.

I use a Meieser gauge to record and repeat what works. Trail This shop always seems to have those gauges. If it's listed on their Amazon or eBay store it will be in the local store. I like the 30 psi because it serves fat and MTB tires.

Trial and error is what really gets it right. Some always do that - just go by feel. The accurate gauge gets me there faster.

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XXX

August 28, 2016, 08:21 AM

Thanks for the reply.  On Friday I did take it out on some trails with 10 in the rear and 8 in the front.  I felt too hard and kind of bouncy when I hit rocks and roots so I will try a bit less next time.

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XXX

August 29, 2016, 02:04 PM

Tubed 14-16 psi offroad
Tubed 6-8 psi Snow
Tubeless 9-11psi offroad
Tubeless 3-4psi Snow

You can balance the air pressure around your weight for road and trail riding by lowering the pressure then raising it until lean-steer/self-steer stops

Im 240 and 10 psi tubeless for summer seems about right. 4ish in the snow.

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