I've got a little over 70miles on my stock chain & it seems to be fine... (probly just jinxed myself)
the rear tire will work (at least mine did)... i just had to adjust everything to get it to clear. i tried to
add an extra set of the metal plates that come with the rag joint as spacers to get the sprocket out further... but decided not to, 'cause you'd have to bend the coaster brake arm to get it to clear the
bolts on the sproket.
i hear ya biknut... i've got a lot of hours in my rear wheel & will def be using an adapter on the next one.
not sure if it was on a Roller but someone on here had a post about cutting the cap over the hub down as apposed to making the center hole in the sprockt bigger... i had already made mine bigger but may try it on my next build (yup, i'm an addict too) lol ...i need to find that post.
gl with your build Card... these things are a lotta fun (building and riding)
The highyway's lime jello & i'm a BBQ'd oyster....