Chainring clock for 5x130mm aero time trial chainring

I work at a bike shop, and they were aggressively cleaning up the service area, resulting in a bunch of stuff getting thrown out, including this awesome 55t Specialized S-Works aero time trial chainring. It looked so damn cool, I couldn't let it get thrown out, but I didn't have much use for it. This made me think of some of the chainring clocks that I've seen here (see below) but most of them are designed for use with a more conventional (non-aero) chainring, so I fired up Fusion 360 and designed my own.

I've got three versions of the clock holder:

• Simple version without hour markers, smooth face.
• Version with 12 hour markers, all the same size.

• Version with 12 hour markers, 12/3/6/9 hours are larger.
  The chainring holder has printed in threads for a standard M8x0.8mm chainring bolt, so you could use standard chainring bolts, or you could use the printable one I've included. Just like FSA aluminum chainring bolts, the printable chainring bolt has a Torx T30 interface which works nicely.

  For the movement, I bought https://www.amazon.com/gp/product/B014IRHBPW/ (Mudder Hands Clock Movement, 3/25 Inch Maximum Dial Thickness, 1/2 Inch Total Shaft Length (Red)) which fit perfectly - not too long, puts the hands in the right place, and the minute hand clears the chain catcher pin by less than 1/8". Obviously other chainrings you might need to remove the chain catcher pin.

  I've included the Fusion 360 files if anyone wants to remix it for their own chainrings. If you do, please post your remix!

Other chainring clocks on Thingiverse

• Fahrrad Kettenblatt Wanduhr / Bicycle Chainring Clock by CBiker
  this one even has clock hands!
• Clock Housing 4 Chainrings 130mm by LukasQ
• Chainring Clock with support by ccarrasco

Print instructions

Category: Sport & Outdoors Summary

I work at a bike shop, and they were aggressively cleaning up the service area, resulting in a bunch of stuff getting thrown out, including this awesome 55t Specialized S-Works aero time trial chainring. It looked so damn cool, I couldn't let it get thrown out, but I didn't have much use for it. This made me think of some of the chainring clocks that I've seen here (see below) but most of them are designed for use with a more conventional (non-aero) chainring, so I fired up Fusion 360 and designed my own.

I've got three versions of the clock holder:

• Simple version without hour markers, smooth face.
• Version with 12 hour markers, all the same size.

• Version with 12 hour markers, 12/3/6/9 hours are larger.
  The chainring holder has printed in threads for a standard M8x0.8mm chainring bolt, so you could use standard chainring bolts, or you could use the printable one I've included. Just like FSA aluminum chainring bolts, the printable chainring bolt has a Torx T30 interface which works nicely.

  For the movement, I bought https://www.amazon.com/gp/product/B014IRHBPW/ (Mudder Hands Clock Movement, 3/25 Inch Maximum Dial Thickness, 1/2 Inch Total Shaft Length (Red)) which fit perfectly - not too long, puts the hands in the right place, and the minute hand clears the chain catcher pin by less than 1/8". Obviously other chainrings you might need to remove the chain catcher pin.

  I've included the Fusion 360 files if anyone wants to remix it for their own chainrings. If you do, please post your remix!

Other chainring clocks on Thingiverse

• Fahrrad Kettenblatt Wanduhr / Bicycle Chainring Clock by CBiker
  this one even has clock hands!
• Clock Housing 4 Chainrings 130mm by LukasQ
• Chainring Clock with support by ccarrasco

  Print Settings

Printer Brand: Prusa

Printer: i3 MK3

Rafts: No

Supports: No

Resolution: 0.15mm

Infill: 20%

Filament: Prusa PLA Silver
Notes:

Printed the clock holder and the chainring bolts at 0.15mm so the chainring threads came out better. Printed the trim ring at 0.20mm, could have printed even coarser.

Everything should orient properly on the print bed and print without supports.