This site contains several different articles about tandem bicycles.

Size	Application	Metric drill	SAE drill
3 mm	Adjusters in rear dropouts
5 mm x .8 mm	Bottle cage mounts, fender eyelets, shift lever bosses.	4.20	#19
6 mm x 1mm	Cantilever bosses, some fender eyelets	5 mm	#9
10 mm x 1mm	Derailer hangers	9.0 mm	"T"
1/2" x 20 L & R	Pedal threads for one-piece cranks
9/16" x 20 L & R	Pedal threads for three-piece cranks
1.375 x 24 tpi L & R	British/I.S.O. bottom brackets
35 x 1mm L & R	French & Swiss bottom brackets
36 x 1mm	Italian bottom brackets

The corresponding nut-like tool for cutting male threads is called a die.

My Tool Tips series features an article on the use of taps.

To remove the sprocket from a threaded driver, the driver must be removed from the hub (otherwise it will just freewheel as you turn it counterclockwise.) As shown in the photo, one good way to secure it is to set it so that the legs are straddling a suitable steel bar, held in a vise. I use a pair of headset wrenches side-by-side, then unscrew the sprocket with a chain whip.

Threaded drivers are fairly rare, and are often sought after because they have the same thread as a standard freewheel hub. This makes it possible to create a hybrid gearing system by screwing a normal freewheel onto the driver. More details on this may be found in my article on my O.T.B. 63-speed bicycle.

Bicycle parts come in even more different thread systems than common nuts and bolts. There are different standards for headsets and bottom brackets for American/BMX/OPC, British, French, Italian, Raleigh and Swiss bicycles.

French and Metric BMX freewheels thread don't work with anything else.

ISO, English and Italian are all semi-interchangeable, but it you shouldn't go back and forth between different types of freewheels on the same hub repeatedly.

Metric threads are specified by diameter followed by the thread pitch (distance between threads)

For example, the common "M5" thread used for water bottle mounts, cable anchor bolts, fender/rack eyelets, shifter mounts etc. bicycles is more specifically described as "5.0 x 0.8" which specifies a 5 mm diameter, with threads 0.8 mm apart.

Similarly, the common "M6" thread used for brake mounting bolts, threadless stems, many seatpost bolts and so forth is actually "M6.0 x 1.0" That's 6 mm diameter, threads 1 mm apart.

Normal coarse metric threads are commonly designated with the letter "M" followed by the diameter, with the thread pitch understood. For example:

• M2 = 2.0 x 0.40 mm
• M2.5 = 2.5 x 0.45 mm
• M3 = 3.0 x 0.50 mm
• M3.5 = 3.5 x 0.60 mm
• M4 = 4.0 x 0.70 mm
• M5 = 5.0 x 0.80 mm
• M6 = 6.0 x 1.00 mm
• M8 = 8.0 x 1.25 mm
• M10 = 10.0 x 1.5 mm
• M12 = 12.0 x 1.75 mm
• M14 = 14.0 x 2.00 mm

See the Headset entry for details and adjustment instructions.

When the Shimano Rapidfire ® and Sun Tour X-Press ® shifters hit the market, confusion resulted, because these, too were operated by the thumbs. This confusion persists, so it is a good idea to avoid the term "thumb shifter." The newer term for these is "top-mount" shifters, as opposed to "below-the-bar" shifters, such as Rapidfire.

T.I.G. welding is commonly used to build lugless bicycle frames. Most current bicycle frame production is done by T.I.G. welding.

The cycling leg of a triathlon is a form of time trial.

There are also team time trials, usually involving teams of 4 or more, taking turns leading and drafting each other. Team time trials require great precision in rotating position within the team.

Time trials are held both on the road and on the track. Bicycles made for time-trial use are designed to be as aerodynamic as possible, even at the expense of degrading handling characteristics and rider comfort. Since riders are on their own, there is no need for fancy maneuvering as there is in a peloton.

A tire is actually made up of three parts:

1. The beads are two hoops of strong steel wire (or, sometimes Kevlar ®.)
2. The cords, cloth forming the body of the tire, woven between the two beads. Most modern tires use nylon cords.
3. The rubber, which covers all the other parts. The rubber on the part that contacts the road is thicker, and is called the tread.

This site includes an extensive article on Tires and also an article explaining the different Tire Sizing systems.

One or two tire irons are usually enough to get all but the most recalcitrant tire beads over the rim, but in extreme cases you may need three. When the third is in place, the middle one can be removed and re-inserted farther over. This is why they are usually sold in sets of three, since you never need more than three.

Since most newer tire levers are made of plastic, the term "tire iron" is a bit anachronistic.

See my Article on Frame Materials.

See Wikipedia for details on this.

The only time it can happen is when the handlebars are turned quite far to the side, which only happens at very low speeds.

Many, many people ride bikes with fairly severe overlap with no practical problems, sometimes having to make a slight adjustment to their pedaling habits at very slow speeds.

On smaller size bikes with full size wheels, it is usually impossible to eliminate overlap without causing adverse fit/handling issues.

Good practice in installing brake shoes is to "toe them in", so that the front part of the shoe hits the rim first. As the brake arm flexes under real braking, it will permit the whole surface of the brake shoe to engage the rim.

Toeing in of brake shoes can also reduce the annoying squeal some brakes make when in use.

Most newer brake shoes have special washers with curved surfaces to allow you to adjust the angle of the shoe to the rim. Older brakes relied on brute force, typically bending the brake arm with an adjustable wrench.

A peculiarity of Top-Swing ® derailers is that the limit stop adjustment screws are reversed, so that the outer screw limits inward travel, and vice versa.

Top-Swing ® derailers clamp on to the seat tube lower down than bottom-swing units. (Some don't even attach to the seat tube, but are held on by the bottom bracket mounting ring.) Some frames made for use with top-swing derailers will not permit the installation of conventional bottom-swing derailers, because there's a bottle braze on in the way. Some suspension frames also require a top-swing front derailer for clearance reasons.

Top-Swing ® or bottom-swing derailers can be (and are) made in either top-pull or bottom-pull versions. (This has to do with the direction from which the cable approaches.)

The length of the top tube is probably the most important dimension in providing a comfortable fit. See my article on Frame Sizing.

Torque is the linear force times the radius at which it is applied. For example, a 10 pound force applied two feet from the axis produces the same torque as a 2 pound force applied ten feet from the axis.

The standard units for measuring torque are pound-feet or Newton-meters. Note that the force unit goes first, so as not to be confused with energy/work measurements. A common error is to refer to "foot-pounds" instead of pound-feet of torque. This is not strictly correct, since the foot-pound is a unit of energy/work, not torque.

This is primarily an automotive tool, especially useful for applications involving crushable gaskets which must be tightened evenly.

Torque wrenches are never needed for bicycle work, although they can be a useful training aid for inexperienced mechanics who haven't learned the feel of a properly-tightened fastener.

To non-cyclists, or casual cyclists, "touring" may mean riding 8 miles on a rented cruiser at a beach resort, or a fund-raising "thon" ride, or any type of riding where the principal objective is leisurely enjoyment of scenery and fresh air.

In the sense more generally accepted in cycling circles, however, a "tour" is a multi-day ride, which is not a competition or a timed event.

See also touring bicycle.

Traditional British touring bags are roughly cylindrical (oriented crossways-no attempt is mad to make them aerodynamic). They come in a range of sizes, usually with a large main compartment and a small pocket at each end. They also feature metal rings on top of the flap to which the rider can strap a rolled-up rain cape, in case the rain stops.

Major brands are Brooks, Carradice, and Karrimor. The better quality bags are made of heavy black canvas, with grey "chrome" leather straps and corner re-inforcements.

This type of bag is not ideal for cyclists who like to stand up and thrash their bicycle from side to side while climbing, because they sway back-and-forth under this type of treatment. For the cyclist with a smooth riding style, they offer a good option for carrying a sizeable load on a bicycle which lacks pannier racks.

This type of bag is currently enjoying a resurgence of popularity.