Torque wrenches available to general industrial work including bicycle work are typically accurate to plus or minus four percent.
Road bike top cap torque.
Same is true for the end cap on a shimano hollowtech ii crankset.
If the motion of the bars feels sticky or hesitant loosen the top cap 1 8th of a turn and test again.
There are basically three types of torque wrenches the beam type the click type and the dial type.
The bung shouldn t creep up the steerer if is installed properly using carbon paste.
It is non load bearing.
Don t over tighten nuts bolts.
As others have said the top cap is pre load only.
In other words a torque wrench set for 100 in lbs might tighten to 96 in lbs or 104 in lbs.
You want the minimum torque to reduce play in the headset.
The correct torque is the amount needed to correctly ensure there is no play in the headset and no more.
Test the headset adjustment by lifting the bike and pushing the bars back and forth the bars should turn freely with very little resistance.
Here s how to do it.
Do it right use this torque guide.
A torque table for bicycles.
Once the stem bolts are then tightened the top cap torque is irrelevant.
Once the stem is tightened in place is is purely cosmetic and covers the top of the steerer.
Tightening your headset is one of the most simple pieces of bike maintenance but it s also very important.
Snug the top cap down until there is slight resistance.