In article , Tony Raven
wrote:

Luke wrote:


The primary device, unlike the secondary, does not simply retain, it
secures. The difference between these two functions is the difference
between having and losing control of the bike.


I thought everyone here was was arguing against me that a loose QR was
not detectable by the rider until it got to the point the wheel was
ejected. Now you are trying to argue that a loose QR will be more than
detectable - it will loose you control of the bike. Which is it?


That's an amusing contradiction. The secondary retention device,
'preferably' takes over in such a manner as to clearly inform that the
QRs have failed to secure the wheel (what if the Lawyers' Lips cite
client privilege, keeping mum?), which in of itself constitutes an
unsafe condition, but is not considered so until the secondary
retention system fails also.


Its a standard analysis for single fault tolerant safety critical
equipment: a single fault shall not create an unsafe condition nor go
undetected. Otherwise an undetected failure can continue obscured by
the secondary system until the secondary system fails and makes the
original fault visible in a potentially unsafe way. Having a loose but
retained front wheel is not of itself unsafe. I've ridden that way with
disk brakes through my mistake a number of times although unlike many
here I pretty quickly knew something was wrong by the feel of the
steering and the knocking sound from the front wheel as the QR hit the
lawyers lips.

Succinctly, here's my argument: What you consider 'wrong' constitutes
an unsafe condition to me; and what precipitates this condition (QR
failing) is characterized as failure. I disagree with your notion that
'a loose but retained front wheel is not of itself unsafe'.

That's all folks.
Luke