Torque Wrenches - my answer... (Fifield, Douglas)

[Gregory Megara]

Yes, I agree, though there are a few caveats. I have a civil engineering background, and being in construction, I have been around a few torque wrenches.

Doug has it correct but I'll make it simpler:

Torque is Force x Length of lever arm. So, to figure the torque on the crank bolt can be done with the derived equation:

Needed Torque on the crank bolt = NT
Length of the torque wrench = LT
Length of 2079 tool = L2079
Setting for torque wrench = TW

TW = (NT * LT) / (LT + L2079)

The problem comes when the torque wrench and the 2079 tool are not in line with each other and that the crank bolt's axis isn't running perpindicular through this whole torquing action which will reduce calculated torque on the crank bolt. But torquing isn't something that can be exacted to the letter in practice. Whatever the NT is in the Bentley manual, there is sure to be a fair amount of leeway around that.

--Greg