This build will work equally well for a Fixie cycle if you do,not have access to a welder.
Step 1: Factors
I do not have access to a welder (except for paying for the job to be done - living on benefits kinda discourages this), so I wanted a mega strong way of locking up the sprocket for my uni.
I had heard about JB weld but although strong I was not confident with it's impact properties i,e when trying to balance there could be high thrust into the JB that could cause it to break down over a short time - but! it might be a good retainer and re-enforcing addition.
Step 2: The Answer
Taking a lot of time and brain pain I came by the perfect insert - the ball bearings from the front wheel of the donor bike, two of these fitted perfectly into the cavity left after removing the ratchet. Super hard and free, no chance of slippage or deformation into the BB metal under thrust/impact.
I still wanted to exploit the JB potential so sent off for a pack.
The idea ended up like this - insert the BBs - fill totally around all internal cavities/teeth stopping any movement - re assemble the unit and fill the cavity behind the locking nut also with JB, packing it around the bearings in there as well.
Blitz it on the bike and give her a go - - seems to be working really well so far.
No good for stunts on a uni or bike I would suggest but for road work there have been no fails of the unit so far.