Yeah probably circlips or maybe locking collars now that I'm mounting everything inside the plates now.
Got my new M6 tap and got the holes all done. Also my bro dropped off some stainless hydraulic tube that has the perfect ID for my M6 bolts so nice precision and zero slop joint the two plates together!
Bit of a design update, since the spade bit 28mm bearing seat worked so well, adding another stage is pretty easy. So going all chain drive, shadow conspiracy 1/2 link bmx chain.
6t to 25t alloy bmx sprocket - 1st stage
6t to 16t acs cross fire - 2nd stage
6t to 33t crank drive - final stage
So about a 51:1 reduction and hopefully around 100rpm at the cranks.
More info coming.