# Reply To: Tire Pressure for Fat Bikes in Snow / Cold

#232397

I’m 175 lbs and usually run 7psi front/9psi back on groomed, 5/7 or lower for soft conditions/breaking trail.  I’m running a Spec Fatboy w/ 4.8″ 26″ tires (tubeless).  Here’s a guide I started with (from Stan’s), remember to include weight of gear in the body weight number.  This isn’t gospel, but its a good starting point:

Stan’s 29er Formula
Body Weight in lb/7=Starting Pressure
Subtract 1 PSI for Front Tire
Add 2 PSI for Rear Tire
Example 150lb/7=21
21-1=20 PSI for Front Tire
21+2=23PSI for Rear Tire

9:ZERO:7 Packed Snow Fat Tire Formula
Body Weight in lb/20=Starting Pressure
Subtract 0.5 PSI for Fat Front Tire
Add 0.5 PSI for Fat Rear Tire
Example 150lb/20=7.5
7.5-0.5=7 PSI for Fat Front Tire
7.5+0.5=8 PSI for Fat Rear Tire

9:ZERO:7 Soft Snow Fat Tire Formula
Body Weight in lb/25=Starting Pressure
Subtract 0.5 PSI for Fat Front Tire
Add 0.5 PSI for Fat Rear
Example 150lb/25=6
6-0.5=5.5 PSI for Fat Front Tire
6+0.5=6.5 PSI for Fat Rear Tire