Gemmy,
Their sheave is the same size as a 20" whl rim, which is what I used
on my DIY; their pulley is a 12,13,or 14t timing pulley
Just when I had everything on my DIY working beautifully disaster
struck. It is with profound sadness I must announce the untimely
demise of my humble yet noble $15 blue Huffy. She cracked a
frame & I had to put her down. Poor old HUffer!
Yet, Behold, She lives on, having donated her organs,( parts),
To my next $15 dollar bike, a sadly abused old school mtn. bike
of undetermined origin. Undetermined becuz it's wearing three
different coats of paint, and is comprised of Japanese, English,
German, & American parts, Some of which are neither metric or inch.
Those must be Chinese. None-the-less, I have her fully restored
except for one derailleur cable and the need of a longer rear skewer.
I think this bike is a world traveler with a life of it's own. I think,
appropriately, I shall name her 'Black Beauty'.