My easy lesson learned on torque. (longish)
Lots of you won't care, but some will-
I picked up a new Specialized Roubaix Expert a few months back. I spent some time tweaking the bars and seat ect. I was concerned about over tightening the clamps on the carbon, so I went conservative on my hand tightening. I have been wrenching on stuff for 25 yrs with no failures, but still wanted to get a torque wrench on the seat post and stem clamp.
I started looking at new wrenches and good ones cost between $180 and $350 for a 0-150 or 0-200 in/lbs. I looked at the $35 park and they looked kinda cheaply made(what do want for $35) All the ones at places like Sears ect go to 600 in/lbs, not much use for stems.
I found a Sturtevant Richmont 0-200 double beam type on EBAY. Brand new, won for $35 inc shipping. I was happy, that is a made in the USA high quality wrench. We just started switching to that brand from Snap-on in the Nuclear industry because they are more reliable than the Snap-ons(according to the Cal-lab people where I work)
Anyway I torque checked my bike and found I had under torqued most things by 1/2. My stem was only at 20 vice 40 and my seat post clamp was 30 vice 55 in/lbs.
I wondered if my EBAY wrench was any good at the lower end of the range, so I brought it to my work and the guys calibrated it-it was perfect out of the box.
I guess the Hard lesson about torque would have been the bars moving on the steerer tube on a long downhill.
The point-Get a torque wrench!