Sunday, January 3, 2016

Fat B Nimble, Fat Be Quick

Just a few days after I built up the 29+ wheel set for my Mukluk, I got my Christmas gifts to myself in the mail. Two updates for my KM:

- a vintage Suntour XC-Pro crank I found on ebay. Now I have two of these as I circle back to 94BCD for my ideal cranks. I love the thin arms and low profile of these cranks--I dropped my Q factor an inch when I changed out the Shimano Deore crank (179mm to 154mm)

- a Panaracer Fat B Nimble tire. For a nominal 29+ tire, this has a smaller casing and is only lightly knobbed. I figured it could fit in the rear of the Monkey, and I was right:

This combination of a steel frame, fat tires, and sharp handling will likely spell the end of my fatbike ownership. The KM is everything I want in a mountain bike right now. Let me explain.
It is simple: normal wheels, so I can easily interchange with the other parts from my bin. Normal headset, normal fork. No wide fatbike hubs needed. Track ends are about my least favorite single speeding method, but they are simple, with little to go wrong. I may feel differently about this if I someday add gears back. I can sell my Mukluk and get rid of three sets of wheels at the same time. That makes my life simpler.

It is steel. Say all you want about good frame being made of all kinds of materials, I like steel. It's slender. It flexes. It's what swords are made from. I like the way it rides. I like the way it looks. I like that it goes with the Dirt Rag "make mine steel" poster in my garage. I like that bike were steel a hundred years ago, and some of those bikes can still be ridden. The frame's tubes aren't too oversized, like those on the Krampus, giving it a better ride and making it more responsive.

It is quick. The big trend these days is slack. Trail bikes. 67 degree head angles and dropper posts and short chainstays and small wheels. Surly got it right with the Karate Monkey 15 years ago, and it's still right today.

It is cheap. I paid $250, shipped, for the frame, fork, and headset. That's about what a mid level carbon fork would cost you these days. I've had many, many bikes, but I've yet to see a positive correlation between increasing price and increasing fun. If anything, cheap and cheerful can carry the day.

My first attempt at fitting the FBN didn't work out so well. I wanted to keep my chainstay as short as possible, so I only added a half link (6mm) to my chain. That put my chainstays at about 444mm, but I got tire rub whenever I accelerated hard. Replacing the half link with a full link (chainstays at 450mm) solved the tire rub:

I took it out this morning for some fast laps around my local Avery loop:

I took the Muk out for some comparison laps, but could only manage two laps (one with 29+, one with the fat tires), before I wanted to get back on the Monkey.

I might have to buy a spare, just in case Panaracer stops making this tire:

Low Q, simple steel, it's all good.


As a side note, on one trip through the Avery woodlot, I saw what I thought was red paint all over the ground:

But no, it looks like a fox that had met its end:

What does the fox say?
Ring ding ding dinAGHH!


  1. Great looking bike! Looks like a fusion of my two most ridden bikes, a Monocog 29er (ditto on the low cost/high fun factor) and a Krampus. I've considered a Karate Monkey MDS frame for a similar purpose. It would be good to consolidate the function of these two bikes as elegantly as you have. Bonus points from a fellow old timer for the XC Pro cranks.

    1. Hi Andy,
      Thanks for the kinds words. I had a Monocog a while back, and I agree that's a bike that punches way above its weight class.
      I may start collecting XC Pro cranks now... I have an XC Comp set as well, and it's not nearly as nice.

  2. Interesting... I've been wanting to try out the plus tire thing, and I happen to have a Karate Monkey. Do you know the internal width of your rims? My current wheelset is pretty narrow.

    Also, for those of us who are still slaves to mechanical advantage, any idea how a front derailleur would work with this setup? I'm guessing it would be pretty tight if it would work at all.

    1. Hi Brian,
      Should have mentioned this in the post: I'm running Velocity Blunt 35 rims, 30mm internal width. A narrower rim would make it easier to fit the tire in the frame; I've run 29+ tires down to about 20mm internal rims.

      I think a FD would work, since I have the wheel about halfway back in the dropouts. That's just a guess though. Don't be a slave! :)


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