Chainring wear gauge

This tool was inspired by this Park Tool video. I thought it was a great idea, & decided to create a handle to make it significantly easier to use.

I don't believe this works for cassettes - the tooth profile is more "square" instead of "round", unlike chainrings.

For cassettes, you'll need to use the Rohloff HG Check tool or similar.

The whole part is 80 mm long to allow you to reach small "granny" gears in triple setups.

I did design a version to accept a roller post-print, but I've never done mid-print captive parts, so I went with this. It worked out great, & the bridging was better than expected.

2020 01 03: added a Rev 4 with a 4 mm side slot to hook on to pegboard hooks.

Print Settings

Printer Brand:

Prusa

Printer:

I3 MK3S

Rafts:

No

Supports:

No

Resolution:

.20

Infill:

20

Filament: Hatchbox PLA Black

Notes:

Made a prototype with these settings, but it turned out well enough that I just kept it.

I made a new version since the picture prototype (rev 2) - this initial upload is rev 3.

3mf file attached if you want to be able to reslice easily with PrusaSlicer.

This tool requires a pause at layer in order to capture a chain roller.

I modeled a thin wall to support the roller in place as the print goes on. You might save a marginal amount of material trying to turn that slice into pure support, but I didn't even bother.

Chain roller

You'll need to get a spare roller from a chain - push a pin out completely to free a roller.

I used an 11 speed chain to source the roller. This chain has about 3200 miles. The roller measures 7.66 mm OD, 5.16 mm ID, & 2.05 mm thickness.

Out of curiosity, I measured a few rollers from a brand new 11 speed chain (SRAM PC-1110) & the OD is nearly identical. The OD is the only dimension that really matters for this application.

Category: Tools