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Fat Camp Podcast #3 with Ken and Andy – Geometry

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Fat Camp Show #3 – Fat-bike Geometry

Show Notes:

  • Fat Bike “Snow” Geometry
    • Slack, low and tight – Hey, isn’t this the same as above?
  • Singletrack race geometry
    • Steep (over 71 degrees), tight (16.5-17”) and high (over 12.5”)
  • “Normal” XC Geometry
  • Neither steep nor slack (70ish degrees), Medium length (17.25-17.5”) and medium height (12-12.25”)

4 Responses to Fat Camp Podcast #3 with Ken and Andy – Geometry

  1. Mark July 13, 2015 at 9:02 am #

    hello love the show!! I have been fat biking for about 4 years now. just got into racing this past winter really got the tire pleasure figured out in the fat bike and my zombie wheeled 29 but my question just got a sarma 29+ I will be going tubless needing to know about what tire pressed to start running my fatbike I run 3.5-9LBS my 29 18-25 so my 29+ ???? also I weight in at 155-165 thanks for everything and again love the show

    • Ken Blakey-Shell July 17, 2015 at 6:25 pm #

      I would suggest starting around 13-14psi and going down from there. There are a ton of variables that come into play for what is the optimal tire pressure for any given rider and trail and personal preference also plays a big role.

      Your experience may be very different but for perspective I run similar pressures in my fat and 29er tires to what you listed and run around 12psi front/13 rear for all of the “true” 3″ 29+ tires and 13psi front and 14.5psi rear on the tires that are a touch smaller (Dirt Wizard and Fat B Nimble).

  2. Bob Hayes July 15, 2015 at 12:16 pm #

    Enjoyed the show, lots of good information. The bike I had with the best frame geometry for me and the way I ride was a 1984 Panasonic ATB. A nice laid back 68 degree head tube angle.

    I recently got a fat bike, a cheap and heavy Mongoose Malus. I wanted to try fat without spending a lot of money. The first thing I noticed riding was that the bike has a lot of oversteer. If I turn the handle bars past about 15 degrees, left or right, they just want to keep turning. Not the bike to ride no hands. What in a geometry would cause this? Is it common in fat bikes? Thanks.

    • Ken Blakey-Shell July 17, 2015 at 6:37 pm #

      Thanks Bob!

      I am guessing you are experiencing “self steer” from the tires and not a geometry thing based upon what you describe. Certain tires are especially prone to self steer and lower pressures and harder surfaces exacerbate the degree of self steer you feel.

      I would recommend running a bit higher pressure (2-4psi should do it in most situations if you are running 7-10psi currently) and seeing if what you are feeling decreases in effect. If the thing you are feeling isn’t as bad, you know it is the tire and not a geometry issue.