| Author | Message | ||
     Xbimmer |
Question for the engineer-types. Since access to several fasteners on our bikes require extensions, am I over-torqueing bolts when I torque to spec using a 12" extension? Seems to me the fastener might be torqued too tight by the time the twist in the extension allows the wrench to read the value... or do I have this backwards?  | ||
| Packdog |
As long as you are careful to keep the torque wrench straight you will be fine. By straight I mean the torque wrench parallel to the fastener and the extension perpendicular. If the wrench is tilted, it will create leverage that will cause the reading to be inaccurate. It also helps to be turning the wrench slowly/carefully. It is standard practice in many industries to "exercise" the click-type torque wrench prior to use. Typically this is done by setting the wrench at 70% of its range and clicking it 10 times. If you've every wondered why some workbenches have a steel bar with sockets welded to it... it's for exercising torque wrenches. Usually there are 3 sockets: 1/4, 3/8, and 1/2 inch drive. The main problem with torque wrench errors is when using crows feet. Using a crows foot adds length to the torque wrench and causes the value being read on the guage (or click on the click type) to be incorrect. | ||
| Jackbequick |
Using crows foot wrenches with torque wrenches is not rocket science. A mechanic should know how to do it and it is easy to do it right: http://www.norbar.com/torquewrenchextensioncalcula tor.php And driving a socket on a nut or bolt through an extension and a universal joint adapter does not change or affect the torque applied unless you get the universal to a very acute angle or let it "kink". I've used them at angles of up to 30 or 45 degrees or so many times and it had no affect at all. Jack | ||
| Lorazepam |
Always "unwind" your torque wrench before putting it away. Leaving it set when stored will ruin the accuracy. | ||
| Xbimmer |
Thanks for the responses, I guess the extension doesn't flex enough to change the torque reading after all, if I'm reading this correctly. I always store my clicker relaxed too, and if in doubt I'll fall back with a beam-type. |
