I'm doing research and development(R&D), in my quest to transmit 212cc engine power THROUGH!!
the frame's bottom bracket(BB).
And keep the pedals working.
No one, including myself, knew which components would work, and which would not.
So I did not buy expensive parts.
Not the cheapest parts, though.
Most parts didn't fit, and were returned or stockpiled.
Surprisingly, most of the parts that did fit bolted right on.
BB internal bearings and spindle screwed out.
BB30 cups and external bearings bolted right on.
Two plastic bearing cups needed lathe-working.
Two lock collars were welded
to sprocket hubs.
An extended BB spindle was bought, then trimmed down.
I did an incredible amount of research into how the bicycle's BB fit and work with its spindle and pedals.
I had another bike with a shift kit, so I knew about jackshafts, sprockets, freewheels and gear ratios.
But yeah, why buy the best, when ya don't even know they'll fit?