#35 Sprocket vs #219 Sprocket

[askmewhy25]

Hi guys!

I bought an Astro 3210 10T at 48V and planning to run it on a 15:1 ratio. I thought of having 8t to 120t but wearing would be really fast and it would we noisy.
I fabricated a #35 120t sprocket but it is too big for 20in tires. I am having problems with the sprocket selection because I want to have a smaller diameter for the sprocket.
From what I have read and recommended by Miles a #219 sprocket set would be the best, the problem is I could not find formulas or calculators for #219 sprocket.
Or can #25 set is another option?

#219 and #35 comparison
http://www.tsracing.com/Techtips/TSchain.html

#35 Calculator
http://www.idleamusements.com/Software/sprocketeer2.htm

That's the problem. 15:1 is a lot to achieve in one stage.

Using 219 chain would reduce the sizes a bit.

Maybe #25 chain would be enough? It doesn't really matter if it wears quickly, as long as it's ok for the duration of the event.

I think 12t should be your absolute minimum size for the drive sprocket.

 

[askmewhy25]

Or would a timing pulley be an option to be more efficient compared with chain drives?

 

[Miles]

This was one of the references that I used before (see page 8)

 

[Miles]

Construction references:
http://www.gizmology.net/sprockets.htm
http://www.gearseds.com/files/design_draw_sprocket_5.pdf

 

[askmewhy25]

Thank you Sir Miles for the references.