About this device
Keywords 3D printing, bicycle, bike chain tensioner, osat, plastic
Uses transportation, hobbyism
Authors Spoonless
Status Prototyped
Made? Yes
Replicated? No
Published 2014
Designed in Michigan, USA
Affiliations MTU
Cost USD $ 6.50
SDGs SDG08 Decent work and economic growth
License data
Hardware CC BY-SA 4.0
Instructions data
Translation data

This chain tensioner can be used to address issues with chain hopping, chain slap, and rattles. It can be printed and assembled for less than $6, and offers equivalent perfomance to comercial products sold for $30.

Bill of Materials[edit | edit source]

  1. Tensioner.scad
  2. (2) ZipTies
  3. (1) 8-32 Thread, 1-1/4" Length Machine Screw (eg. McMasterCarr:91792A201)
  4. (1) 8-32 Thread Locknut (eg. McMasterCarr:91831a009)

Tools needed[edit | edit source]

  1. MOST Delta RepRap or similar RepRap 3-D printer
  2. Screwdriver
  3. Adjustable Wrench or Pliers

Skills and knowledge needed[edit | edit source]

  • Ability to use a 3d printer.
  • Ability to use a wrench and screwdriver.

Technical Specifications and Assembly Instructions[edit | edit source]

All parts are symetric such that component orientation is not an issue.


  1. Ziptie the cage to the Bicycle frame just above chain.
  2. Hold the chain up so it is captured in the cage.
  3. Bolt the pully in place
  4. gently crank the pedals by hand and shift throug all gears to ensure nothing is binding

Common Problems and Solutions[edit | edit source]

  • If the fit to they bicycle is loose or overly tight the OpenScad variable "pipeDia" can be set to match your bike frame's tubing diameter.

Cost savings[edit | edit source]

  • Approximatly $23.50 (78.3%)
    • 30g of PLA at approx. $30/kg = $0.90
    • Machine Screw, Locknut, and bag of zip ties approx $5.60 at local hardware store
    • Equivalent Chain Tesnsioner: Bionicon C.GUIDE approx. $30
    • 30 - (5.60 + 0.90) = $23.50