Instructables

Converting a Mountain Bike to a Single Speed Bike.

Picture of Converting a Mountain Bike to a Single Speed Bike.
I have recently had my bike taken apart and resprayed.

I am trying to learn more about bike mechanics as I reassemble it, with the help of my bike mechanic beau.

I never got on with the gears on the bike before the respray, so I have decided to turn the bike into a single speed machine.

This Instructable covers the following:
  • Installing bottom brackets (the cylindrical shaped part that goes through the frame and allows the cranks to spin.)
  • Installing the cranks (the bits between the bottom bracket and the pedals.)
  • Installing pedals (hope you know what pedals are)
  • Installing a single speed conversion kit.
You will need these tools:
  • 5mm Allen key
  • 8mm Allen key
  • Flat bladed screwdriver or chain ring bolt tool
  • Bottom bracket spline tool
  • Large adjustable spanner
  • Pedal spanner
  • Chain tool
  • Cassette lock ring tool
  • Bike grease
These are specialist bicycle tools, if you don't have them, look for a community bicycle workshop in your area.
 
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Step 1: Assemble your crank and chain ring.

My bike had a fairly standard mountain bike triple crank set, as pictured in the first photo of this step.

As we're converting to single speed, we only need a single chain ring at the front.

We found a double crank set from an old racer and removed the largest chain ring. (Sorry- no photo of the double rings.)

To undo the chain ring bolts, you need a 5mm Allen key and another tool to hold the back of the chain ring bolt. If you haven't got a chain ring bolt tool, you can use a large flat bladed screw driver.

As we removed the large chain ring we had to space out the chain ring bolts with washers so they would tighten properly. You can just see the washers in the third photograph.

We also moved the chain ring to the outside of the crank spider as we knew it would help the chain line in the long run.

cwebb114 months ago
ive converted many of my old bikes to single speed. but after having trouble with the conversion kits snapping on me(lots of tourque going up hills) I switched to just plain track hubs and fixed gear. less moving parts and less maintaining. but great 'ible!
Uncle Kudzu9 months ago
Good info! My old mountain bike had horizontal dropouts, which made the process of conversion simpler. Also, a BMX freewheel sprocket worked for me - i didn't know there conversion kits available. i love the simplicity of a single speed. Sometimes i think about an internal 3-speed hub, but i always end up enjoying life on the single.
Snotflower (author)  Uncle Kudzu9 months ago

Hey there, the conversion kits only work on a free hub type of rear
wheel. I think I will always be a single speed girl from now on, a much
simpler cycling experience

Ah, yes, the freehub. My old bike had the gear cluster with the freewheel mechanism built-in. 20+ year-old technology. But yeah, single is simplicity.