I don't know, but I would guess that the answer is #2... "Luigi keeps breaking the cranks..."

To be fair/reasonable, the bike industry wasn't much for good engineering in terms of stress and strain calculations. We wouldn't be breaking so many Campy seatpost binder bolts, etc., if they were. The amount of data on customers was pretty minimal back in the 60's and 70's too. Big industries, like autos and aviation, presumably had better data, at least in terms of making stuff fit the majority of customers.

There's also the competing goal of making parts as light as possible, combined with the assumption that racers will be fairly light, but powerful. Not sure how well that matches with the loads generated by heavy and low-power recreational riders.

Having watched the military aviation industry over some time, I know that they do a lot of analysis up front and tons of testing of the final item, but still get caught with the customer using the aircraft in ways that they didn't expect, and early failures showing up as a result. The early F-18 Hornets ended up with early cracking at the base of the rudders, requiring some external gussets being added, as well as a strake added to leading edge extension to break up the vortices that were hitting the rudders during high AOA flight.



we now return you to the bike-oriented content that you tuned in for...

Steve in Peoria