If there is one tool every home mechanic should own, it is the torque wench and a proper knowledge of how to use it.
Let me say that again: if you work on your own bike, get a torque wrench and learn how to use it. Over the last few years I have seen innumerable failures from improperly tightened parts on bikes. From crushed carbon posts, cracked frames, broken handlebars and stripped out stems; almost every break could have been prevented with a properly tightened bolt. If a bolt is too loose, you risk damaging the parts by them slipping or coming loose over time. Too tight and you risk cracking or crushing your components. With all the carbon fiber, and superlight alloys available today cracking or crushing a nice bike part is all too common.
A torque wrench is designed to put a pre-determined amount of torque on a fastener (bolt). To put it simply, torque is the amount of force you put on the fastener when you tighten it. Almost every component and bike manufacturer has published the right amount of torque to put on every small fastener on your bike. These specifications are usually expressed in newton-meters, and are sometimes published right on the bike! Newton-meters are often expressed as “Nm.”
To use a torque wrench we use the dial (usually located on the bottom of the handle) to set the proper torque. We set that to the same number as expressed on the bike part or specification given from the manufacturer. For example, if a stem bolt should be tightened to 6Nm, we would set our torque wrench to 6Nm. As we tighten the fastener (bolt) we eventually will feel a click or be given an indication that we’re at the proper torque. This ensures that the fastener is like Goldilocks in the Wee Bears bed, “just right”.
Torque wrenches are manufactured by many companies, and some make them specifically for bikes including Pedros, Park Tool, Tacx, and Shimano PRO. Our shop favorite is the small Shimano PRO, pictured above. It includes most of the bits you’ll need to work on your bike and make adjustments. It’s well made, is easy to use and gives a audible “click!” when the proper torque (tightness) is reached. We have one in our RETUL fit room and one to compliment the Park Tool wrenches we use in the back. The PRO torque wrench comes in a plastic case with conversion tables molded right into it, just in case your components proper toque is not expressed in Newton-Meters.
If you work on your bike, get a torque wrench before you make your next adjustment. If you’re interested in purchasing one, we have Shimano PRO wrenches in stock, and we’ll even show you how to use it!