Lou Deeter wrote:
>
> Once upon a time, I rebuilt sports cars. For the record, they met the date limitation as "classic" for this list. I recall that greasing threads was taboo because it allowed you to over tighten a nut or bolt when using a torque wrench, resulting in deformation of the threads and increased likelihood of bolts breaking. Likewise, the logic against greasing the tapers on the bb--you could potentially overtighten the crank, deforming the soft metal of the crank. Of course, 1960s logic also said that you couldn't rotate radial tires left to right, but tire improvements make that a myth today, so I guess it is possible for there to have been studies that debunked the old theories about greasing things too. Since this is a classic list, I will stick to classic methods. It has worked for me thus far. Lou Deeter, "enjoying the 60 degree day in Monterey" Orlando FL
-------------------------------- Proper procedure for tightening nuts and bolts to a torque value has _always_ required greasing the threads and having a washer under the bolt head or the nut depending on application. This is the only way to insure consistent and repeatable tension to a specified torque value. (I use antiseize compound in place of grease.)
You cannot (according to Jobst) crack a crank by over-tightening the crank bolt. The head of the bolt will break off first. You can however crack a crank by repeatedly tightening the bolt over a period of rides.
Frequently Asked Question (FAQ) site:
http://draco.acs.uci.edu/
Here's the Frequently Asked Question:
http://draco.acs.uci.edu/
Pertinent part: "The admonition to not lubricate the tapers of the crank spindle seems to find life only on bicycle cranks, of all the machines I have seen. I have pursued the "dry assembly" instruction by talking to crank manufacturers and discovered that they apparently had warranty claims from customers who split their cranks open. It is easy to prove that cranks cannot split by over-tightening simply by attempting to do so. It is not possible to split a major brand crank this way, the bolt will fail first.
Crank failure from "over-tightening" is caused by the re-tightening of previously properly installed cranks. Once installed, a crank always squirms on its taper, and because the retaining bolt prevents it from coming off, it elbows itself away from the bolt and up the taper ever so slightly. This can be detected by the looseness of the retaining bolt after the bicycle has been ridden hard."
Chuck Schmidt
SoPas, SoCal