Quote:

Many thousands of bikes have been successfully and safely built from scratch, starting with a bare frame.



Consider the context of the thread, there is not even a bare frame here. Would you advise a novice bike builder to design and build his frame from stock tubing? In my opinion there a bit of a difference between ordering components from vendors then assembling them, and a true 'from scratch' build. (Design, fabricate, etc.) In the case of the proposed PVC tube safety mechanism, that would be akin to a person rummaging about in the left over parts bin for pieces with which to cobble together a brake for his ride.

I am not downing Rich at all here; he asked for suggestions/feedback, and with few exceptions has gotten reasonable (for laymen) attempts at answers. From my own experience, I would take an existing design and modify it where possible to fit the intended application. Purchasing essential components that are beyond my means to duplicate, and fabricating the remainder. As I am not an elevator designer/builder, that is the best answer I can give... outside of actually consulting elevator savvy peeps who know what is and is not feasible far better than I.

2018 FLHCS 2014 Surly Straggler - 16,000 miles and counting!