How to construct a bicycle chainwheel?

[andreas.scheucherautodesk.hobby]

Hi,

I found some youtube tutorials for sprockets, but nothing really good for a chainwheel where I only know the inner diameter and the tooth count.

Do you know a tutorial how to construct one?

Thanks for your input.

Andreas

[jhackney1972 · Accepted solution]

You will need the Pitch Circle diameter of the sprocket in order to model.  This website, at the bottom, will help you calculate this.  After that search the internet for help with tooth shape.  i do not know what you are referring to when you say you have the "inner" diameter.  If you are talking about the Pitch Circle diameter then forget this site.

As for as videos on Chain Sprocket design, you probably cannot beat Lars Christensen YouTube video.

[andreas.scheucherautodesk.hobby]

Hi @jhackney1972 !

Thanks, this video looks much better!

With inner diameter I mean the bottom of the cutout for the chain bolt. I know, creative naming. I hope you know what I am talking about... that was the easiest to measure.

But given all bicycle chains have the same link length, with trigonometry it should be possible to cut the circle in 2x24 triangles and calculate the lengths of the sides of it... But I guess this is an exercise for  another day! 😄

I will give it a try tomorrow.

[jhackney1972]

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[Warmingup1953]

Do you mean what I call the Chainring?

[andreas.scheucherautodesk.hobby]

Exactly! Yes, you are right. Chainwheel was the wrong therm. Non native here...

Though your's is even a special case, as it's a narrow wide chainring.

[andreas.scheucherautodesk.hobby]

I still haven't found time to test your solution, as this is just a side project of mine. But I will accept it as solved and ask again, when it give it a try and can't solve it with your suggested video and page.

Thanks so far!