Torque Specifications and Concepts (2023)

August 25, 2015/Miscellaneous Topics

This article will discuss the basics of torque and torque wrench use. See also related article on Basic Thread Concepts. This article includes a table of various torque recommendations.

1

Introduction to Torque

Threaded fasteners, such as nuts and bolts, are used to hold many components to the bike. As a fastener is tightened, the fastener actually flexes and stretches, much like a rubber band. This stretching is not permanent, but it gives the joint force to hold together, called “preload,” or tension. Each fastener is designed for a certain range of tension. Too much tightening will deform the threads or the parts. Too little preload will mean the fastener will loosen with use. This can damage components, such as a crank ridden with a loose mounting bolt. Loose bolts and nuts are also generally the source of various creaking on the bike.

Tension in the fastener depends largely upon the amount of torque, the tightening, and the size of the thread. Generally, engineers will specify a thread size large enough to handle the anticipated stresses. For example, the M5 bolt of a water bottle cage bolt would not be a good choice for holding a crank. Even if the bolt were as tight as possible, it would not provide enough force to hold the arm secure to the spindle. The crank-to-spindle interface receives quite a lot of stress, making larger threads (M8, M12, M14) a better choice. The amount of pressure applied by a thread can be substantial in order to hold the joint secure. For example, a fully tightened crank bolt can provide over 14,000 Newton force (3,000 pounds force) as it holds the arm in place.

(Video) Torque Specifications And What They Mean

It is commonly believed that bolts and nuts often come loose “on their own”, for no apparent reason. However, the common cause for threaded fasteners loosening is simply lack of tension during initial assembly. Vibration, stress, use, or abuse cannot typically overcome the amount of clamping force in a properly sized and secured threaded fastener. As a simple rule of thumb, any fastener should be tightened as tight as possible without failure of the thread or the component parts. This means the weakest part of the joint determines the limits of tension, and hence, torque.

2

Torque Measurements

Torque for mechanics is simply a twisting or turning motion around the axis of the thread. This resistance can be correlated to, but is not a direct measurement of, fastener tension. Generally, the higher the rotational resistance, the greater tension in the threaded fastener. In other words, the more effort it takes to tighten a bolt, the tighter it is.

Torque is measured as a unit of force acting on a rotating lever of some set length. In the bike industry and elsewhere, the common unit used to measure torque is the Newton meter (abbreviated Nm). One Newton meter is a force of one Newton on a one meter long lever. Another unit sometimes seen is the Kilogram-centimeter (abbreviated kgf-cm), which is a kilogram of force acting on a lever one centimeter long. It is possible to convert between the various systems.

Also sometimes used in the United States is the inch-pound (abbreviated in-lb.).This is a force of one pound acting at the end of a lever (wrench) that is one inch long. Another torque unit used in the USA is the foot-pound (abbreviated ft-lb.), which is the force in pounds along a one-foot long lever. It is possible to convert between the two units by multiplying or dividing by twelve. Because it can become confusing, it is best to stick to one designation. The units given on the torque table here will be in inch-pounds.

It is possible to convert between the various systems:

(Video) HORSEPOWER VS TORQUE SIMPLEST EXPLANATION

  • Nm = in-lb x 0.113
  • Nm = ft-lb x 1.356
  • Nm = kg-cm x 0.0981

3

Torque Wrench Types

Torque wrenches are simply tools for measuring resistance to rotation. There is a correlation between the tension in the bolt and the effort it takes to turn it. Any tool, even a torque wrench, should be used with common sense. A cross-threaded bolt will not properly tighten even with a torque wrench. The mechanic must be aware of the purpose of torque, and what torque and fastener preload are doing to the component joint. It is also important to consider thread preparation, which is discussed in detail in this article.

Beam Type

Park Tool offers two styles of beam type torque wrenches. Both wrenches use 3/8″ square drive to accept standard 3/8″ bits.

The TW-1.2 has a range of 0–14 Nm (0–140 inch-pounds). The TW-2.2 has a range of 0–60 Nm (0–50 foot-pounds).

The beam design is relatively simple, and is accurate for both left-hand and right-hand threading. The socket head holds two steel beams, a primary beam and an indicator or pointer beam. The primary beam deflects as the handle is pulled. The separate pointer beam remains un-deflected, and the primary beam below flexes and moves with the handle. The reading is taken at the end of the pointer, at the reading plate on the primary beam. The handle is moved until the desired reading is attained. These wrenches rarely require re-calibration. If the pointer needle is not pointing to zero when the tool is at rest, it is simply bent back until it does align. Fatigue in the steel is not an issue.

Torque Specifications and Concepts (1)

Click Type

Park Tool offers two styles of “click” style torque wrenches. Both wrenches use 3/8″ square drive to accept standard 3/8″ bits.

(Video) Horsepower vs Torque - A Simple Explanation

The TW-5.2 has a range of 2–14 Nm (18–124 inch-pounds). The TW-6.2 has a range of 10–60 Nm (88–530 inch-pounds).

The term “click type” can be misleading. This design of torque wrenches uses a swiveling head. There is a spring that is compressed by turning the handle. At higher settings the spring is compressed more which will allow the head to swivel only at higher resistance of higher torque. At high setting there is an audible “click” noise. But at lower setting there may be little or no noise as the head moves over as it swivels. The head swiveling indicates the resistance or torque has been reached, not the “click” noise.

Torque Specifications and Concepts (2)

4

Bicycle Torque Specifications

Below is a table of torque equivalents and formulas for conversions follow the torque table. The table is also available as a PDF file.

All figures in the table below are in Newton meters and inch-pounds. Note that some companies do not specify torque for certain components or parts. Contact the manufacturer for the most up to date specifications.

Wheel, Hub, Rear Cog Area

ComponentType/BrandNewton MetersInch-Pounds
Spoke tensionTorque is typically not used in wheels. Spoke tension is measured by deflection. Contact rim manufacturer for specific tension recommendations. See TM-1.
Axle Quick-release: closed cam typeMeasured torque not typically used. Common industry practice is resistance at lever half way through swing from open to fully closed. For more see Tire and Tube Removal and Installation.
Solid axle nuts
(non-quick-release type wheels)
29.4–44266–390
Cassette sprocket lockringShimano®29.4–49260–434
SRAM®40354
Campagnolo®50442
Hub cone locking nutBontrager®17150

Chris King®

12.2100
Shimano®9.8–24.587–217
Freehub bodyBontrager®45400

Shimano®

35–50305–434
Shimano® XTR w/ 14mm Hex45–50392–434

Headset, Handlebar, Seat and Seat Post Area

ComponentType/BrandNewton MetersInch-Pounds
Threaded headset locknutChris King® Gripnut type14.6–17130–150
Tange-Seiki®24.5217
Stem binder bolt: Quill type for threaded headsetsShimano®19.6–29.4174–260
Generic brand range16-18144–168
Threadless stem steering column binder boltsDeda®871
FSA® carbon8.878
Syncros® cotter bolt type10.190
Thomson®5.448
Time® Monolink548
Race Face®6.255
Stem handlebar binder: 1 or 2 binder boltsShimano®19.6–29.4174–260
Control Tech®13.6–16.3120–144
Stem handlebar binder: 4-bolt faceplateControl Tech®13.6–16.3120–144
Deda® magnesium871
FSA® OS-115 carbon8.878
Race Face®6.255
Thomson®5.448
Time® Monolink653
MTB handlebar end extensionsCane Creek®7.970
Control Tech®16.3144
Seat rail binderShimano®20–30174–260
Campagnolo®22194
Control Tech® two-bolt type16.3144
Control Tech® one-bolt type33.9300
Syncros®5 each bolt44.2 each bolt
Time® Monolink544.2
Truvativ®M8 bolt: 22–24
M6 bolt: 6–7.1
M8 bolt: 195–212
M6 bolt: 53–63
Seat post binder*Campagnolo®4–6.836–60

*NOTE: Seat posts require only minimal tightening to not slip downward. Avoid over tightening.

(Video) Torque, Basic Introduction, Lever Arm, Moment of Force, Simple Machines & Mechanical Advantage

Crankset, Bottom Bracket and Pedal Area

ComponentType/BrandNewton MetersInch-Pounds
Pedal into crankShimano®35 minimum309.7 minimum
Campagnolo®40354
Ritchey®34.7307
Truvativ®31.2–33.9276–300
Compression slotted crank pinch boltsShimano® Hollowtech® II9.9–14.988–132
FSA® MegaExo™9.8–11.387–100
Crank adjusting capShimano® Hollowtech® II0.5–0.74–6
FSA® MegaExo™0.5–0.74–6
Crank bolt (including spline-type cranks and square-spindle cranks)Shimano®34–44305–391
Shimano® Octalink® XTR® (M15 thread)40.3–49357–435
Campagnolo®32–38282–336
Campagnolo® Ultra-Torque®42371
FSA® M8 bolt34–39304–347
FSA® M14 steel49–59434–521
Race Face®54480
Syncros®27240
Truvativ ® ISIS Drive43–47384–420
Truvativ® square spindle38–42336–372
White Industries™27–34240–300
Crank bolt one-key release capShimano®5–6.844–60
Truvativ®12–14107–124
Chainring cassette to crankarm (lockring)Shimano®50–70443–620
Chainring bolt: steelShimano®7.9–10.770–95
Campagnolo®871
Race Face®11.3100
Truvativ®12.1–14107–124
Chainring bolt: aluminumShimano®5–1044–88.5
Campagnolo®870.8
Truvativ®8–970.8–79.6
Bottom bracket: cartridge typeShimano®49.1–68.7435–608
Shimano® Hollowtech® II34.5–49.1305–435
Campagnolo® (three-piece type)70612
Campagnolo® Ultra-Torque® cups35310
FSA®39.2–49347–434
Race Face®47.5420
Truvativ®33.9–40.7300–360
White Industries™27240

Derailleur and Shift Lever Area

ComponentType/BrandNewton MetersInch-Pounds
Drop bar dual control brake/shift lever clamp boltShimano® STI™6–853–70
Campagnolo®1089
SRAM®6–853–70
Shift lever: upright/flat bar typeShimano® STI™5–7.444–69
Shift lever: twist gripShimano® Revoshift®6–853–70
SRAM®17150
Shift lever: MTB “thumb type”Shimano® STI™2.4–322–26
Front derailleur clamp mountCampagnolo®544
Campagnolo®762
Shimano®5–744–62
SRAM®4.539.8
SRAM®5–744–62
Front derailleur cable pinch boltShimano®5-6.844–60
Campagnolo®544
Mavic®5–744–62
SRAM®4.540
Rear derailleur mounting boltShimano®

8–10

70–86
SRAM®8–1070–86
Campagnolo®15133
Rear derailleur cable pinch boltShimano®5–744–60
SRAM®4–535.4–44.2
Campagnolo®653
Rear derailleur pulley wheel boltShimano®2.9–3.927–34

Brake Caliper and Lever Area

ComponentType/BrandNewton MetersInch-Pounds
Upright bar brake leversShimano®6–853–69
Avid®5–744–62
Campagnolo®1089
Brake caliper mount to frame:
side-pull, dual-pivot, center-pull
Shimano®7.8–9.870–86
Campagnolo®1089
Cane Creek®7.7–8.168–72
Tektro®8–1069–89
Brake caliper mount to frame:
linear-pull or cantilever
Shimano®8–1069–89
SRAM®5–6.845–60
Avid®4.9–6.943–61
Control Tech®11.3–13.6100–120
Tektro®6–853–69
Brake pad:
threaded stud
Avid®5.9–7.853–69
Campagnolo®871
Cane Creek®6.3–6.756–60
Tektro®5–743–61
Shimano®5–743–61
SRAM®5.7–7.950–70
Brake pad:
smooth stud
Shimano®7.9–8.870–78
Brake pad:
side-pull and dual-pivot bolts
Campagnolo®872
Cane Creek®6.3–6.756–60
Shimano®6–853–69
Tektro®5–743–61
Brake cable pinch bolt:
linear pull & cantilever
Control Tech®4.5–6.840–60
Shimano®6–7.853–69
SRAM®5.6–7.950–70
Tektro®6–853–69
Brake cable pinch bolt:
side pull/dual pivot/center pull
Campagnolo®544
Cane Creek®7.7–8.168–72
Mavic®7–962–80
Shimano®6–853–69
Tektro®6–853–69

Disc Brake Systems

ComponentType/BrandNewton MetersInch-Pounds
Disc rotor to hub: lockringAvid®40350
Shimano®40350
Disc rotor to hub: M5 boltsAvid®6.255
Hayes®5.650
Magura®3.834
Shimano®2–418–35
Caliper body mountAvid®9–10.280–90
Hayes®12.4
9 with Manitou forks
110
80 with Manitou forks
Magura®5.751
Shimano®6–853–69
Tektro®6–853–69
Hydraulic hose fittingsHayes®6.255

Formulas for converting other torque designations into Newton meter (Nm) and inch pounds (in-lb.):

Torque Equivalencies

Newton meter (Nm)Approximate Inch-pound (in-lb.)Approximate foot-pound (ft-lbs)
18.90.7
217.71.5
326.62.2
435.43.0
544.33.7
653.14.4
762.05.2
870.85.9
979.76.6
1088.57.4
1197.48.1
12106.28.9
13115.19.6
14123.910.3
15132.811.1
16141.611.8
17150.512.5
18159.313.3
19168.214.0
20177.014.8
21185.915.5
22194.716.2
23203.617.0
24212.417.7
25221.318.4
26230.119.2
27239.019.9
28247.820.7
29256.721.4
30265.522.1
31274.422.9
32283.223.6
33292.124.3
34300.925.1
35309.825.8
36318.626.6
37327.527.3
38336.328.0
39345.228.8
40354.029.5
41362.930.2
42371.731.0
43380.631.7
44389.432.5
45398.333.2
46407.133.9
47416.034.7
48424.835.4
49433.736.1
50442.636.9

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FAQs

What is the torque specification? ›

By definition, torque refers to the amount of rotational force at the point of application. When attaching a wheel to a vehicle, torque specifications are the amount of force recommended on the hardware to ensure proper installation. Following exact torque specifications matters for a number of reasons.

How are torque specifications determined? ›

DETERMINING TORQUE

The general equation for bolt load based on applied torque is T = KFiDb where K = torque coefficient. K is a function of the coefficients of friction and collar friction in the joint, and these are based on variables such as surface finish, coatings, and so on.

Why is it important to torque? ›

In simple terms, you need torque to create tension in a bolt. You use torque to turn a nut onto a bolt and then to stretch the bolt, making it a solid spring that clamps the two materials together.

How much torque does a cassette need? ›

Got Torque ?
Bottom Bracket
Bottom bracket cups300-360 lb/in (32.9-40.7 Nm)
Cable clamp bolt50-70 lb/in (5.7-7.9 Nm)
Cassette
Lockring261-434 lb/in (30-50 Nm)
91 more rows

What is K in torque? ›

T = K×F×D. where T is the torque measurement, K is the nut factor, F is the tension and D is the bolt diameter. With this equation, if you know K, F and D, you can multiply them to get the torque needed to tighten the bolt so that it has the right amount of tension.

How do you set torque value? ›

How To Set Torque Value and Use Click Style Torque Wrench - YouTube

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