Is it possible to make a new sprocket a skip tooth while making the rear hup a 5 or 7 speed.. I want the look stil just not the actual thing.. some vintage parts are just ridiculous price wise.. and i want first gear up hill I'm lazy..lol
You have to use an even number of teeth. Example for chainrings, 44, 46, 48 teeth, etc and grind off every other one. Here is my bike with a genuine skip tooth cog, skip tooth chain and a chainring with every other tooth ground off.
Here is a 20 tooth cog with every other tooth ground off. Again I used a skip tooth chain. Modern cogs and chainrings have narrower teeth so it will wear out a skip tooth chain faster than if you use real wider cogs and chainrings. Always mark the teeth you want to grind off before you start. Cogs have to also have an even number off teeth to do this.
If you just want the look, just grind off every other tooth on an even tooth chainring and use a standard 1/2 inch pitch single speed chain. This conversion is usually a little noisy, but real skip tooth chains are noisy. You can leave the cog alone if you want and this will allow for more gear variety than if you grind every other tooth off a cog. You can use even and uneven tooth count cogs this way. So yes do this. If it doesn’t work as smoothly as you like, go and buy a new chainring. When you do this conversion a straight chain line is required or you could end out dropping chains. It works but any conversion or mis matching of parts on these old bikes is a learning experience.