Bikes of the Bunch: Surly Pugsley as Tonka II, the second car

by Andy White


This edition of Bikes of the Bunch features something a little different to the bikes typically covered. Here Andy White of Australian-based Fyxo shares the build of a new “urban e-bike for big kids” that he built for his friend Todd Knight. From our count, this is the seventh bike of Todd’s that we’ve featured in CyclingTips’s 13-year existence. This story, written by Andy White, was originally published at fyxo.co.


One great thing about art is its ability to start a conversation.

This bike – far from a work of art – certainly has that ability.  The massive tyres, the racks, that light, and a motor! Why?

I’ve conducted many ‘social experiments’ in my time with e-bikes. It involves throwing someone on one, who has at that point in time never ridden one. Within two pedal strokes, their face lights up like at Christmas; sometimes a giddy shriek accompanies it. They always come back with their mind opened.

Now, I’m not saying this bike is pretty but I’d like to think it has a utilitarian beauty to it. After many e-bike conversion builds this one looks less e-bike and more bikepacking adventure/zombie apocalypse rig.

The true appeal of e-bikes came to me shortly after my new job – as Dad. A few years into the role, I did what most parents do, and got a wee-ride, which evolved to the kid-carrier on the rear rack, then ‘the chariot’ (an attached half bicycle for them to pedal, or not, behind). Some of the toughest rides I’ve done have been with the chariot, loaded with kid, dog and toys, into a block headwind.

After some quick googling, I found a reasonably priced entry-level ‘e-MTB’ which just so happened to be a fat bike with a Bafang mid-drive motor. I was an instant convert. 

Where it started.

After dabbling with adding racks and integrating lights, I discovered Bafang’s range of mid-drive motors which you can install on almost any bike. I’d grown a soft spot for fat bikes and found a viable donor, a Surly Wednesday. A year later, this is how it looked before it went to a new home.

Meet Tonka, the original. This one has had many owners now.

As is the nature of the beast, more than a few people asked about the build, and one wanted a Tonka of their own.

Tonka II

A seemingly rare bird now, and one of the earliest examples of a fat bike, a Surly Pugsley formed the basis for the build.   

Any sensible #parentmobile/car alternative is going to have full fenders, racks to carry supplies, and integrated lights so you are never caught out. And so those were a given.

Tonka II.

The SRAM X9 10-speed (confusing much?) rear derailleur didn’t have the range I’d hoped for, which is why I opted for the smaller 36T chainring. One thing that anyone reading this and hoping to replicate the build will discover is that an aftermarket chainring is a must to get a reasonable chainline. The 36T with 8 mm offset met both criteria, though typically a 42T with the 18 mm offset will give the optimum chainline.

Another great thing about fat tyres is the massive volume of air. Running 10 psi feels very firm, and should you get a slow leak, it takes an eternity for enough air to escape to the point of feeling squeamish. Plus they’re tubeless with sealant, so slow leaks typically go away pretty quick. Not pictured is the Schraeder adapter that I keep on one valve so you can top up at a petrol/gas station.

The dropper post was a late addition to the build and makes mounting and dismounting the rig so much easier when it’s loaded or just stopping at the lights. It’s a little luxury that also allows partners to ride the bike and adjust the seat height easily.

A dropper opens the bike up to others jumping on without having to adjust things.

The initial plan was to house the cables in a frame bag above the battery like my first build. I had the Blackburn Outpost frame bag in my ‘bikepacking’ tub and realised that with a little modification it would make for a cleaner build, and keep the kryptonite of all electrical devices (water) a little further away.

The stock wiring from the battery sled, motor, and lights was upgraded to XT60 plugs, soldered and heat-shrunk for the same reasons as above. 

The power

Oh yeah – the motor!

Bafang offers a range of models from 250-1,000 W in 36-52 V. If your plan is to electrify a fat bike your options are narrowed to the BBSHD 1,000 W with 100 or 120 mm BB widths.  

The Bafang e-bike upgrade.

Installation is easy. Remove the existing crankset, slide the Bafang Mid-Drive in its place, secure with the lockring, and wire it up. Making it neat is another thing completely.

There is an optional gear sensor, throttle, and brake sensor which I found unnecessary as I wanted a pedal-assisted bike (i.e. the motor is only activated while you pedal). Not an electric scooter.

You can choose between three, five, and nine levels of assist, and the speed limit for the assist can be set to suit your country in the control unit.   

The 48 V battery allows you more options for powering other devices, one being lights. Some Bafang models have a 3 V line out from the motor for powering lights. The 4WD LED light bar shown is wired directly to the battery, with a switch (hidden in the frame bag) to toggle power to the unit.

Things to hold things

Just like you might have in your car, your phone is all manner of things – GPS for navigation, music, podcasts, and making calls. I’ve been using the Quad Lock case and mounts for years and there is none better – they’re also based in Melburn [this can be found in close geological proximity to the Australian city of Melbourne – ed.]

Dashboard navigation.

Racks! Blackburn Outpost adventure cage for holding water, Blackburn Local Basket Front rack, with nifty integrated lock holder. A nod to my bike messenger past by keeping the keys on the bars so you don’t forget them, and onto the wrist when you lock up.

Some of the other choices were a piece from here and a piece from there, like the Pirelli saddle, Nitto Bullmoose bars, and ‘Nice Bike’ bell.

The number plate was a last-minute idea, purely for fun – like the spirit of the build, and family adventures it will assist with.  

Try one

Some of the greatest rides of my life have been on a bike like this with my kid.

Many may shake their fist, or thump their keyboard about the rise of e-bikes, and a myriad of reasons why ‘it’s cheating’, and yet no one begrudges anyone from having a motor in their car, which is just another tool of conveyance and convenience.

My guess is they are yet to ride one and have their eyes opened.  

The build

  • Frame: Surly Pugsley, size medium
  • Fork:  Surly Pugsley
  • Headset: Cane Creek
  • Rims: Surly MOBD
  • Hubs: Surly
  • Spokes: Really? Black!
  • Shifters: SRAM X9
  • Crankset: Bafang, 36T chainring
  • Bottom bracket: Bafang BBSHD, 1,000 W mid-drive
  • Battery: 48 V / 15 AH battery, 500c Bafang display
  • Rear derailleur: SRAM X9
  • Cassette: SRAM, 11-36T
  • Chain: SRAM 10-speed
  • Brakes: Shimano Deore hydraulic, 180 mm rotors
  • Tyres: Surly Nate 26×3.8, tubeless, of course
  • Handlebar: Nitto Bullmoose Cromo
  • Stem: NA
  • Seatpost: Brand X Ascend II
  • Cages: Blackburn Outpost
  • Bar tape: Lock on Grips
  • Saddle: San Marco PIRELLI
  • Pedals: SIXSIXONE
  • Extras: Blackburn Outpost Frame bag, Blackburn Local Basket Front Rack, Grunt straps (Bunnings’s answer to Voile at a fraction of the price), Quad Lock.
  • Weight: 32.4 kg

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