MSeries posted ...

Maybe I should ask this in rec.bicycles.tech, they are keen on
torque-ing there. Who uses a torque wrench for their bikes ? What
sort is it ? For years I haven't and had only few problems, my cranks
came loose once ! but I know I should do things in accordance with
the manuals especially on my best bike. Also I read on r.b.t that
some one was getting a proper tool for the Shimano self extracting
crankset bolt cap, has anyone seen these for sale in the UK ? How
would one manage to tighten the cap to the correct torque (3-7 Nm)
with what I imagine is simply a small pin spanner ? I reckon it
wouldn't really matter for this as it takes no stress in normal
usage.

Opinions please.

Having been a 'Torque Control Engineer' for Desoutter (they make power tools
and GR Electronic Torque Control systems) for a while of my working life,
and having worked on the Raleigh production line, well, the Dyna-Tech part
anyway, among many others, it was notable that the torque specs given by
most manufacturing companies are mainly for use in the factories using power
tools and not necessarily for home users to stick to. The torque
characteristics of a hand and power turned bolt are completely different and
use different torque values.

Most Torque specs are also, nowadays, a sop to the ligitious society in USA
and provide an extra level of 'get-out' insurance for component failure.

IMHO a small 'home' torque wrench, used intermittently and probably without
practice and under less than ideal conditions, can do more harm than good.
I never use a torque wrench nowadays, except when re-building the bottom end
of an engine, or other 'safety critical' component, like brake disc bolts
for instance. General bicycle maintenance is happily reliant upon 'feel'
and the correct sizes of spanner. One good reason for the differing lengths
of spanners for differing sizes of nuts is the amount of leverage (torque)
that can be transmitted.


--
Paul