The old Pug.

As Tyler will attest, project bikes can be a huge amount of fun. Being able to pick an choose each part, only to build it up with your own two hands can be incredibly satisfying. Ever since my first ride aboard an early Pugsley I have wanted to build my own fatbike, only to build many for friends and customers rather than myself. However, seeing as how our shop Pugsley shown above is gone (same with the shop), it seemed as good a time as any to finally build a fatbike.

Project Fatbike will not only be a showcase for some great products that are either designed for, or compatible with fatbikes, but I also hope to take a closer look at a fatbike’s use as well.

Wonder if it’s possible to build a fatbike with spare parts? Read on, after the break.

Honestly, one of the things that got me thinking I could finally build a fatbike was the amount of spare parts I had lying around my basement. I have been scheming for awhile as to what I would build up with all the parts, when I asked myself why not a fat bike? That got me thinking about what you really need to build a fatbike. Regardless of how many parts you have sitting around, there are certainly some fatbike specific parts that you probably won’t have on a shelf:

  • Frame and Fork
  • Rims
  • Hubs*
  • Tires
  • Tubes
  • Rimstrips*
  • Crank and bottom bracket*
  • Front derailleur*

All of the above parts are basically the only fatbike specific parts you need, though the parts with *’s are dependant on the situation. Just for the sake of this post, let’s assume that you have decided to build a Surly Pugsley.


There is actually a pretty good chance you would use a Pugsley frameset for a build like this as it’s honestly one of the best for the job, as it’s one of the cheapest at around $575 (with fork) and it offers nearly every option you could think of, and requires fewer proprietary parts than some other fatbikes. It was for these exact reasons that we chose to use the new Pugsley Necromancer frame for our build. It should be noted though, that the Necromancer edition of the Pugsley does not come with a fork so you will have to pick one out when ordering your frame. This actually worked in our favor though, as we will be reviewing what looks to be one of the raddest fatbike forks around. Stay tuned to find out which one.

So if you’re using a Pugsley frame, both hubs are just standard 135mm spaced quick release rear hubs so there is a chance you or your buddies might have a few lying around.

Rimstrip wise, if you don’t want to shell out for new strips and you don’t mind the handyman’s secret weapon hidden inside your tires, good old duct tape works just fine.



Crankset wise, this is where it gets a bit more complicated. Pugsleys, and most fatbikes, use a 100mm wide bottom bracket shell in order for the cranks to clear the chainstays, and the chainline to clear the tire. If you have any old ISIS crank, you’re in luck as new 100mm wide ISIS bottom brackets can be sourced from both FSA and Truvativ. Also, if you happen to have a newer crank that utilizes the Truvativ Howitzer interface you can get 100mm wide bottom brackets for those as well. If you don’t have either of those, you’ll have to buy a new crank and BB set from either those mentioned, or specific fatbike cranksets such as the e*thirteen XC crank or Surly Mr. Whirly, among others.

Finally, due to the 100mm wide bottom bracket a special front derailleur is needed as well. There is a chance you might have an old E-type mech sitting in some forgotten parts box somewhere, which will work just fine. Also, if you find yourself with a newer D-Mount (high direct mount) front derailleur that’s not being used, all you will need is this handy adapter from Problem Solvers (more on that later).

Obviously, with all of the unique parts needed for the build it’s a stretch to consider it a parts build. However if you have a drivetrain, brakes, seat, seatpost, headset, stem, handlebar, grips, and pedals at your disposal – building a fat bike can be a great use of your old parts. While Project Fatbike started as an attempt at a spare parts build, it has quickly evolved into a showcase for some awesome products, both new and old. Stay tuned for the play by play!


  1. Fat biker on

    Should’ve started with a real fatbike frame (fatback or 907). Aluminum, designed by folks in Alaska who know riding on snow. Did I mention they’re only $599 and are gorgeous compared to a fugsley?
    Also, 135mm makes for a cheap, but weak wheel. Spend another hundred and go with a 170mm hub instead.

  2. Fat Arrow on

    @ Fat Biker- Surly has been around for a long time in the Fat game. Fatback may have been first but Surly took it to another level. Also 9 Zero 7 is a 135 mm rear end btw. I’ve been mountain biking on a Pugsley for 4 years and never had problems with the offset 135. The 135 hub gives you significantly more options for wheel builds, and as of now there aren’t any 170 spaced IGH’s which is popular in the fat community. Fatbacks are nice bikes- but not very many shops in the lower 48- especially further from AK, are going to carry those. The Necro-pugs gives the best frame/build options IMO.

    Also just go to for the latest info on all things fat.

  3. Pants and Jacket on

    All over the internet, I see all these rude, arrogant people talking/bragging about Fatback/507 frames and how awesome they are, and it makes me want to avoid their products at all costs. If those are the types I am going to be associated with when I’m out riding, no thanks.

    Gary Fisher managed to claim he “invented the mountain bike” or whatever, without coming off like a jacka**, perhaps other people should consider taking the same course when talking about certain products.

  4. Kovas on

    Always loved the fatbike concept, but hated the thought of having a 1-season bike. Quick Q to those who ride the fat… Come summertime, is it possible to swap-out the fat wheels for some 29er hoops, or is clearance going to be an issue (will only 26 do)?

    Since the Fat tires are so “fat”, can you put in a decent size 29er tire in the same frame (like a 2.2)? This way have 2 bikes in one?

  5. Pat on

    @ Kovas:
    I built up a Pugs last winter, but by the time I was done, all the snow was gone.
    I discovered that fatbikes are fun for just about every condition. I put hundreds of miles on my Pugs, and even raced it once to a respectable finish. I liked it so much, that I just bought a fully blinged-out Ti fatbike from Twenty2 Cycles. Dropped around 9 pounds in the process, and upped the fun factor. You can absolutely put a set of 29″ wheels on them. The outside diameter of the 26″ fat tire is almost identical. But why would you want to?

    @P&J: where are you seeing these “rude, arrogant people”? I’m on the MTBR Fat Bike forum often, and it’s one of the most attitude and flame-free bike forums I’ve seen. If enthusiasm = jacka**, then saddle me up.

  6. Nanci Drew on

    @Kovas: No one ever said it’s a “one-season” bike. Fat tires are far from only good in the snow; they rock sand, roots, tacky, anything you want. The do-it-all bike doesn’t exist; there are only do-it-all riders.

    To your question though. I have played with the idea of having a swappable 29r wheel-set made in offset for the pugs. But the cost for a custom wheelset that is only going to be used on one bike is turning me off of the idea. The fat tires already have a 29″ diameter and swapping to a standard 29er wheelset and tire combo is only going to make the ride rougher by taking away all the squish that comes with a 3″ tall tire running 8-12 psi. I’m gonna spend the money on a set of Nates and shred year-round.

  7. Noah on

    @Fatback and @ZachOverholt – the brake adapter for the White Brothers Snowpack fork will be ready before the end of the month. This adapter allows the use of a 135mm rear disc hub – out of the box the fork is setup for a 135mm FRONT disc hub (compatible hubs are available from Paul Components and Phil Wood).

    You said “raddest fatbike forks around” so I assume you’re talking about the Snowpack. 🙂

  8. MattS on

    Sorry to hear about the demise of the shop…

    I built my first fat bike this fall too, also a Pugsley (white, wish it were purple or brown).

    Mine was a classic ‘I’ve got a seat collar I need to build a bike around’ type project. I had a Hope Big Un red rear hub sitting around since 1999, waiting for the right over-the-top application (either a longbike or a tandem), so I built the Pugsley around it. My buddy Rodd hooked my up with a vintage Race Face Turbine crankset in ISIS, My homie Jamie contributed a set of Hayes Mags with Razor Rock blades, to which I installed the RED Goodrich lines I’d had sitting in waiting for three years. I breathed new life into a duct-taped red Selle Italia, dug out my old platforms, chucked on a take-off XTR e-type derailleur I’d been sitting on since my last wrenching job, and topped it all off with a vintage set of Deore thumbshifters mated to a rapid-rise XTR derailleur shifting a 12 year old 8speed cassette reduced to 7 speed, powered by a Syncros 24t granny and a Black Spire 34t DH ring. Booya, tonnes of retired parts back in action and all working superbly (pretty much).

    The fattie sure does turn heads over at the nearby toboggan hill. 45kph is exciting, just mind the kids.

  9. fanboy on

    wow, the haters.

    I’ve ridden Fatback, Salsa (both 170mm rear spacing) and Surly (135 rear).

    the advantage to the 170mm NON offset rear is negated by the lack of interchangability of the wheels (front to back).

    I run a regular deraileur system in the rear and an old school screw on single speed rear hub in the front. If I have an issue with the gears, I can swap the wheels around and ride out.

    In my mind the difference is race v’s adventure.

    The 170mm rear wheel design(s) are race bikes. The rear wheel may be a little stronger but you loose the ability to swap the wheels. In an adventure situation, that is the difference.

    Interesting that the Simpson Desert Bike Challenge ( was won in 2011 on a Pugsley (despite there being a range of Salsa and Fatback bikes in alloy and ti frames)

    oh and if you’re after the “ultimate” fat fork for racing, how about

  10. The Man on

    The entire amount of credit for the popularity of these bikes is deserved to Surly. Sure, smaller brands like Wildfire came before. But the brands that snobs are touting like 907 and Fatback didnt come along until well after Surly made the huge risk and investment of making a tire. And they continue every year, coming out with new tires. That crotchety old bastard up at Fatback sure has a lot of balls claiming that he invented everything, slamming Surly all the while he is completely beholden to them to provide him with tires. If not for Surly, he would not have a business. And the new 45N tire – that kicks ass! It was designed by the Industrial Designer from Salsa and the engineer from Surly. There is only one place that is churning out top level product and that is QBP and all of their brands, and they are doing it without bravado and bragging.

    Kudos to Surly and team.

  11. Fatback on

    Just ran across this and felt I’d chime in being the “crotchety old bastard” with a lot of balls. First off, I am old, but not the least bit crotchety-you must be mixing me up with one of the other companies mentioned who is none too happy about Surly using the offset design. Me-I have always loved the Surly folks and still do. You have not, and will not hear me slam anything Surly, nor do I claim to have invented fat tire bikes. The development of these bikes goes back into the 80’s, and there are many folks who had a hand in getting us where we are today. Frame builders Steve Baker, Chris Yelverton, and John Evingson were some of the early pioneers of the sport. Simon Rakower was early on with the Snowcat rims, then came Ray Remolino making offset frames, rims and sand tires, followed closely by Mark Gronewald of Wildfire fame who brought us up to the start of Surly, along with Carl at Vicious. Thanks to all of those people/companies, including Q for taking the risk making the Endomorph.


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