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Tuesday, February 12, 2019

Single Speed, It Is

It's a subtle thing. The pull to simplicity. To just get out there. To just be.

And it always seems to lead me to a bicycle. The most simple one. A rigid single speed.

I have commuted single speed or fixed since the mid 90's, raced cyclocross single speed beginning in the late 90's, and mountain biked exclusively rigid single speed from 2003-2018. Single speed speaks to me.

Even for gravel, at first. Throughout 2013, my first season riding gravel events, I rode my Torelli cyclocross single speed all over, including the Gold Rush, Odin's Revenge and Gravel Worlds. I loved gravel events, but not so much the cyclocross bike's quick handling or single speed. I searched for a more capable bike for those long rough road rides.

Eventually, I landed on the Black Mountain Cycles Monster Cross bike for a go anywhere geared road bike. But I hedged. A significant part of my purchasing decision was Mike Varley's perceptive design detail of old school semi-horizontal dropouts, which allowed an easy in-the-field conversion to single speed. Of course, that also left open the possibility of a more permanent single speed.

Black Mountain Cycles Monster Cross set up for all day single speeding on most any road. 

After four memorable seasons riding gravel geared, I somehow entered the single speed class in the 2018 Gold Rush Gravel Grinder. I still don't know what prompted that, other than just to see if I still could. A Single Speed Gold Rush.

With that taste of gravel single speed still lingering, Mark Stevenson (aka Guitar Ted) and Dave Roll (aka N.Y. Roll) announced the C.O.G. 100 Iowa Gravel Single Speed Championship, a self-supported, self-navigated, no frills 100+ mile gravel race. It's just you, your fellow riders and whatever you discover out there on an unknown, unmarked course. With the C.O.G. 100 featuring just about everything I love about grass roots gravel, I had to find a way to make it there. Keeping It Real - The C.O.G. 100.

Once cleared by work and home for another Grinnell road trip, I spent a quiet winter afternoon converting the Black Mountain to a single speed complying with the C.O.G. 100 requirements of one chain ring, one cog, no front derailleur, no shifters, no shift cables, and no cassette/freewheel.

One chain ring + one chain guard = same bolts from the removed double chain ring setup.

I first removed the front derailleur, rear derailleur and shift cables. I then removed the Salsa Cowbell handlebars, complete with its shifters, and simply installed slightly wider Salsa CowChipper handlebars with brake levers only. Easy-peasy.

The one chain ring rule required removing two chain rings and installing just one. Lacking the niceties of shorter bolts to make this work, I found in my shrinking parts bin an old Salsa chain ring with 42 shark teeth. A few minutes with a hacksaw turned that unusable chain ring into a shade tree mechanic chain guard. Problem solved.

Old cassette spacers align the cog with the chain ring and help secure it to the dropout.

The one cog rule required removing the cassette and installing just one cog. My simple solution for a single speed rear wheel was to use my existing wheel with a BMX single speed cog aligned with the front chain ring and held in place with spacers extracted from old cassettes. Another shade tree mechanic fix.

Not much left. Shorten the chain to an appropriate length, tighten the chain to an appropriate tension by sliding the rear wheel back and up the semi-horizontal dropout and secure it all with a stout quick release. That's it.

Chain tension adjusted by sliding the rear axle along the semi-horizontal dropout. No brake adjustment necessary.

This set up will not get onto the cover of Single Speed Today. But, yes, it works well. I have ridden and raced many years on trails and cyclocross courses on similar setups.

Now, it's time for the C.O.G. 100.

Addendum 1.  This post describes what I did, but not how. For a post describing how to convert a bike to single speed in the field, as in during an event, go to this post. Field Conversion to Single Speed. The only additional steps for the C.O.G. 100 are to remove some extra stuff (the derailleurs, shifters, shift cables, cassette and a front chain ring) and install a single rear cog.

Addendum 2.  The chain tension must be loose enough to operate, but not so loose as to slip off. The operational tolerance here is not high. If your frame lacks a semi-horizontal dropout, you most likely will have to maintain chain tension another way, such as an eccentric bottom bracket, an eccentric rear hub, or a chain tensioner like a rear derailleur or a Surly Singulator. Sheldon Brown - Single Speed Conversion.

Addendum 3.  Of course, a primo set up includes a single speed specific rear wheel with a single speed freewheel held with a bolt on skewer. I've built several wheels like this over the years and still have one for my commuter bike (Surly hub, WTB rim, White Industries ENO freewheel). I would do this on the Black Mountain if I were committed to running single speed for more than an event or two.


  1. Looks like a nice setup, one of these days I'll get a gravel single speed rig but for the C.O.G. it'll be my trusty Santa Cruz Highball since it is currently my only single speed bike.

  2. Thanks, Rob. This is a simple conversion using bits on hand, but it works. I'm sure we'll see much more elegant single speeds at the C.O.G. 100. Whatever folks are riding, it's going to be a hoot! See you there!

  3. I will be bring my 1987 Trek 330 converted to twenty-six inch wheels along with a Crust Romanceur fork. 2.3 in front, 1.8 out back, running 40/22, using the same freehub and space mod. It gets around New England pretty well.... "muck-n-hill" as I say. The gearing makes swapping back to 700x38 pretty easy.

  4. Sounds like that set up would roll through most anything the C.O.G. throws at you. Love it.