Bike Build – Single gear conversion

I got into biking a few years ago when my buddy Simon helped me get my first bike from the Penn State craigslist!  I learned a lot from maintaining my bike.  My wife Regina received one an old 3 geared internal Columbia hub bike for free from our friend’s brother who builds bikes for non-profits and friends.  Check out his website! To try something new I decided to try and build a single gear bike with minimal funds for Regina.  It took about $200 + amazon gift cards and 10 months to buy and find all the parts, new and old from craigslist, amazon, LBS, Ebay, and other bike websites.  Pictured below is the Kent 10 spd frame I bought for $20 in Colorado while on a work trip.  I shipped it back for more than double the purchase price, but it was still cheaper than anything i could have found in NYC. 🙂 Photo of the 50cm frame after the removal of the foam grips and chain ring.Prep work done on the frame:

  • Clipped off F/R derailers, shifters, and cable housing.
  • Removed the old aluminum extension brake levers, brake set (didn’t fit new wheel set), and reflectors.
  • Drilled holes in the frame to fit new brake set. I ended up switching the front and rear brakes and made it fit the frame. (See Mounting recessed-mounting calipers on older frames)
  • Cleaned, degreased, and regreased the fork and 3 piece bottom bracket using degreaser and bike lube.  It was pretty nasty.
  • Ripped off the old foam handle bar grips.
  • Used baking soda and vinegar to remove the ubiquitous rust from the handlebar and frame!  The handlebar was particularly covered.

Here’s the bike post clean up, wheel set and chain ring/cranks installed w/ original brake set and cables.  New/used parts acquired from craiglist, amazon, ebay, and bike websites:

  • Replaced the 3 speed chain ring and cranks with a used 46T chain ring and 165mm cranks.
  • New wheel set, 16T cog, 16T freewheel, and a blue chain!
  • A guy from craigslist sold me a new brake set (to fit new wheels and frame), new brake levers, cable housing, and 2 new tires for $65.  He either didn’t know what he was doing or that stuff was HOT.  I lean towards the former :).  This helped tremendously in keeping the costs down.
  • Bought pedals from a LBS.  The guys from NY’s Waterfront Bicycle shop were cool.
  • I used an old bike seat I owned.  I ended up buying a new white bike seat to match the wheels.  $18.50 shipped!


  • Found dead bees, 4 of them, in the bottom bracket.
  • Learned how to remove rust.
  • I learned all about cottered cranks, brake sets, and old frame specs.
  • Bike parts aren’t as interchangeable as I thought (at least between the old and new parts)
  • Enjoyed the process of building and restoring a lot!
  • I would do this again for sure.  I’ m on the lookout for another frame to work on.


16T rear cog, Shimano MX 16T Single Speed Freewheel (16T X 3/32-Inch)
46T chain ring 165mm cottered cranks
KMC Z410 Bicycle Chain (1-Speed, 1/2 x 1/8-Inch, 112L, Blue)
50cm Steel Kent Gran Concur 10sp bike frame
Tektro RL570 levers
Tektro RL320 Dual Pivot Calipers
Continental Ultra Sport 700c/23
Wellgo Track Pedals 9/16″
Origin 8 Saddle Pro
1 purple paw sticker 🙂

Finished product — Inside.

The cranks/chain ring and frame look new in the photo, but there are a lot of nicks and imperfections present.  The original decals and stickers are starting to peel off as well.  Maybe one day I’ll repaint the frame following – Mike’s Bikes Part 1 Part 2.

Out in the wild!

6 thoughts on “Bike Build – Single gear conversion

  1. I happen to have an identical Kent which I am trying to do something similar with – but I can’t figure out how to get the old crankset / bottom bracket off. Its like nothing I’ve seen before and I’m stumped. Any chance you could enlighten me?

  2. Michelle, I’ve also had trouble removing the bottom bracket. It was a function of rust and dirt buildup that made it hard to remove. To remove it, i sprayed lubricant and wd-40 on the bracket. I used two adjustable pair of pliers on either side of the bracket, one to turn and the other to stabilize. I didn’t have the correct tools on hand. I can’t remember the correct direction to turn the wrench, you might want to look it up on the web. Hope that helps!

  3. Hey, I’ve just bought the same bike at a local flea market and I am trying to convert it into a fixie, the bike came with 26 inch tires I was wondering what size tires did you end up throwing on these? Wondering if a 700c would fit but i’m not quite sure

  4. David, I put on 700c tires. The issue will be installing the brakeset so that it aligns with the newly sizes tires. Two options when buying a new brakeset: 1- drill a new hole on the frame (not recommended) 2 – use the front brake set on the back tire and the rear brake set on the front tire. There’s a link in my post about this. Have fun!

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