Using a Torque Wrench

Never before in the history of cycling equipment has this magic gauge of tightness been so necessary. Titanium, carbon, ultra steels, feathery aluminum, magnesium and various combos are being used in components. They demand precise tightness during installation and adjustment. The only way to do it right is with a torque wrench.

Most manufacturers have websites that tell you exactly how much torque to put on every bolt. Follow the values as if your life depends on it, because it does. Think about the consequences of your overtightened stem bolts shearing while you're sprinting to the city limit sign or bashing through a bumpy downhill turn.

Consider a torque wrench an essential cycling tool. The cool thing is, you can order one through your local bike shop for delivery in just a few days. There are several models that do a great job.

• Park Tool. The tool masters make two versions: TW-1 for 0-60 inch-pounds (0-6.8 Newton meters or Nm) and TW-2 for 0-600 inch-pounds (0- 67.8 Nm). These cost $50 and $60, respectively.

• Pedro's. The Pro torque wrench measures 20-200 inch-pounds (2.3-22.6 Nm) and costs $170. You can purchase a 9-piece hex bit set for this wrench for an extra $12.

• Syntace. This one's a beauty at nearly $300. Measures 1-20 Nm (8.9-177 inch-pounds). A set of bits is available for $95.

• Snap On. If you can chase down a truck, the driver will gladly sell you a torque wrench. Mine is the TE-12A Torqometer with a super accurate dial gauge that measures 0-150 inch-pounds in increments of 2.5. It cost me over $200 when I bought it 20 years ago, so I imagine it's a bit more now.

Crankarms require so much torque (300 inch-pounds) that you probably don't need to measure it. You just need to reef on it. It's those smaller torque values (15-85 inch-pounds) that must be totally accurate. Follow the instructions that come with the wrench and figure out which bits you need for your bike. You can usually get bits at a hardware store tool department.

Parts manufactured in metric countries will list torque values as either Newton meters (Nm) or kilograms of force per centimeter (kgf-cm). Here in America, it's inch-pounds or foot-pounds. Easy to convert:

• foot-pounds x 12 = inch-pounds
• inch-pounds x 1.15 = kilograms of force per centimeter (kgf-cm)
• inch-pounds x 0.113 = Newton meters (Nm)
• kilograms of force per centimeter (kgf-cm) x 1.36 = Newton meters (Nm)
• Newton meters (Nm) x 8.851 = inch-pounds