Driveline reliability.

This is why I have been having no driveline problems with The Pig even after so many miles. It took quite a bit of tweaking to get it this straight, but the payoff is trouble-free long term reliability.
The better your chain and sprocket alignment is, the more reliable your bike will be.

Notice the twist in the idler mount which keeps the chain right in the center of the sprocket no matter if the wheel spins forward or reverse. There are no popping or rubbing sounds and very little friction.
Take the extra time to get things lined up like this and enjoy fewer chain issues.

I run #40 hd chain. I must run the tensioner due to the bend in the lower frame stay to prevent the chain rubbing the frame. Plus I'm lazy and this is already done.
I have never had a single chain problem since building The Pig and I ride every single day.
This is my only transportation and MUST be reliable if I want to eat.
The reason I get such great results is because I address the areas that matter, and I keep it simple.
Notice there are no "boost bottles" or N.O.S. kits on my builds. No ported cylinders or big bore carbs. No stroker cranks or oversized pistons.
I don't try to go fast on it. That is not what it is meant for.
If I want to cruise at 45mph, I'll build a Morini or stuff a 5spd mini motocross motor in a custom frame.
I don't ask too much of my little china girl so I am rarely disappointed.

Much less friction and noise when pedaling as well. That box of HD chain was the best $20 bucks I ever spent