OK, so I’ve wanted to get a fat bike for some time now and when surly came out with the olive drab Pug Ops, I had to have one. A lot of people call these snow bikes, and they are fun in certain types of snow, but they are more commonly know as Fat Bikes. I’m not trying to sell you on fat bikes here, just to share riding impressions and a review of the mechanical and design aspects of the Surly.
These bikes are rigid, i.e. no suspension except for the fat tires, that means a lot of bone jarring hits and tooth rattling if not ridden smoothly.
The main focus on these bikes are the massive tires, these ones are embossed as 26 x 4.0″, but advertised by Surly as 26 x 3.8. This is just an insight into the difference between referencing section width (between sidewalls) and the overall width at the widest point between the lugs on the tread, which on these tires stick out past the sidewall.
Surly bikes are spec’d, how should I say? Very conservatively, I mean, do they even make LX derailleurs anymore? C’mon Surly, that is a cheap-out for sure. Instead of telling you in excruciating detail what parts are on it blah blah blah (available at surlybikes.com), Ill explain the highlights and what I felt necessary to change and why.
Stock Long Cage Shimano LX, Not even in production anymore! In the photo above, I swapped this for an XT, Shadow Plus (with a clutch to stop chain slap). A much needed upgrade, especially on a rigid bike ridden on anything other than the softest of surfaces at the slowest of speeds.
Stock Brakes are Avid BB7 mechanical units. Mechanical? I get it they don’t freeze up in 40 below conditions etc etc, but really, they are terrible, require constant adjustment to avoid pad rubbing, are 50% as strong as hydro brakes and require cable service to maintain a consistent feel as dirt contaminates the housing. I replaced these with Shimano SLX units, since here at least, we do not get 40 below weather and actually ride down hills and need real brakes.
Stock: Generic 2 bolt 110 mm(!) 5 degrees rise. I mean really? Old school for sure and another nod to the fact that Surly is from Minnesota and not BC. I shortened this up to 65 mm with a 6 degree rise to make it a little more playful on the steeps.
Stock: Generic mushroom narrow grips, I replaced these with beefier, softer, ODI Rogue Lock-on grips. These are my personal favourite and I put them on all of my mountain bikes. Easier on the hand (more surface area) better shock absorption (a real consideration on this bike) and more secure locking (2 rings vs 1).
Wheels and Tires, As mentioned these things are huge, they are the same outside diameter as a 29″ x 2.25″ tire (right around 29″ measured on the tape and compared to one of my XC bikes hanging in the garage. These bikes are effectively 29’ers in disguise. Key to utilizing the massive high volume tires to their full advantage is air pressure. For soft conditions—3-5 psi, for trails—8-10 psi. That does not sound like much, but its over a 300% increase in pressure at 10 psi vs 5! Looooow pressure is needed for CLIMBING in the soft snow more than anything, and in Squamish, its up or down, there is not flat. The Surly Nate 120 Tpi tires are amazing in the traction department with the lugs at a cavernous spacing and a towering 6 mm high! This thing is like a tractor rolling down the street, well maybe not that quiet. The Rolling Darry rims are 82 mm wide, compare that to 19 mm for XC and 23 mm for trail/All mtn on “regular” mountain bikes. Everything adds up to floatation and traction. And apparently, these bikes float in water, although I have not tried that one. My mechanical background just won’t let it happen.
The frame echoes the early days of fat bikes with standard 135 mm rear drop-out spacing, With this, and to accommodate proper chain clearance past the tire, the frame is offset to the drive side 17.5 mm. This means that the wheel needs to be laced with a matching offset of the hub to keep the tire and rim in the middle of the bike. Looks strange initially, but this way allows you to use any MTB hub you wish (with QR of course). A lot of new fat bike designs are coming with specific 170 mm spacing and symmetrical frames, but this limits you to a line of fat bike specific hubs (i.e. Surly Ice Cream Truck)
Speaking of drop-outs, the frame gives you horizontal track ends that allows you to run single speed without any trouble (same as my Karate Monkey), but with a geared set-up makes wheel changes a bit more awkward where you have to remove the QR skewer completely to clear the chain without a fight.
Drive Train Highlights:
Surly’s own offset double crank and 100 mm BB are used to play nicely with the offset rear end. this crank seems decent enough with a clamp style non-drive side crank arm and external BB cups, at least they did not use a square taper piece of crap. Gearing is 2×10 spd with a Deore level cassette and generic galvanized chain. Shifters are SLX with indicator windows and a 2x or 3x switch on the front shifter. I have found that shifting is pretty soft, but it may be a combination of the off-brand chain and the full cable housing.
This thing leaves a huge smile on your face when you first start riding it and you cannot stop staring at the massive tire in front of you. When it is aired up around 10 psi it feels pretty normal and handles like most rigid bikes, aired down with squishy tires, the steering feels very lazy and unnerving, but at low pressures, you are normally going much slower than you are used to. The gearing is very adequate for climbing with a 24 Tooth small ring and a 32 tooth on the cassette. As a single speeder, I find this easy gear a real luxury. Once you have the cockpit set-up to be familiar and comfortable, there are no real surprises. The fork, being Chro-moly steel like the rest of the frame, is very flexible and shutters a bit under hard braking, but the frame is very compliant and soft so that, coupled with the high volume, soft tires, makes it more comfortable than you might expect. There are tons of bottle cage and fender/rack mounts (20!, yes 20 bolt locations in all on this thing) since it is meant as an adventure/bike packing machine. Climbing on loose surfaces is a cinch since you never risk spinning a wheel and can settle in a spin away up the climbs. I learned after about the first 10 feet of riding that this is no race rig, but something much more utilitarian and “muscular” i.e. slower, it does after all tip the scales at 35 lbs. Thats almost 13 pounds heavier than my XC Race bike. Almost the same as riding my XC bike and carrying my road bike on my back, but I could never ride the same conditions in the soft terrain as I can on this machine. It will probably stay in the fleet for some time.