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A metal disc with a hole in the middle. There are several different types of washers used on bicycles, to serve different purposes: ******* flat washer, keyed washer, spacer, radiussed, serrated washer anti-roation (S-A)

Wedge bolt

Conventional handlebar stems use a long bolt running down the middle of the shaft to clamp the stem to the inside of the steerer. At the bottom of the stem shaft this bolt screws into a special shaped nut. These nuts are of two different types:

Each system has advantages and disadvantages:

Note: Steerers are butted at the bottom, so the hole in the steerer is constant-diameter until near the bottom, then the walls taper inward in the butted section.

It is vitally important that the stem extender (or stem) is not inserted so far that the wedge is installed where the steerer is narrowing, or it could come loose unpredictably.

When this happens, only the edge/corner of the quill or wedge contacts the steerer, and it is trying to "grab" a slanted surface.

This is sometimes a problem on smaller frames if you try to insert the stem or a stem riser too far down into the steerer.

Stem Inserted Too Far

Illustration by Nicholas Flower

See also Hands Up! Adjusting Handlebar Height


Disparaging term used by recumbent fans to describe a conventional upright bicycle.


A noted manufacturer of rims and (formerly) brakes. Formerly, Weinmann was based in Belgium and Switzerland, but the current Weinmann company is U.S. based.


A process of joining similar metals by heating them so that they melt into one another. Compare to brazing.

Westrick Rim

A colloquial name for Raleigh pattern rims. "Westrick" is a made-up word combining "Westwood" with "Endrick." Westwood rims were only for use with rod brakes; Endrick rims were only for use with caliper brakes, but Raleigh Pattern, a.k.a. "Westrick" rims can be used with either type.

They combine the raised (or dropped, depending how you look at it) center that keeps rod brake shoes free from the risk of hitting the spokes, with the flat sides required for rim brakes.

Westwood Rim

The old-fashioned type of rim usually seen on roadsters. Westwood rims have rounded sides, so they are not suitable for use with caliper brakes. They are designed to be used on bikes with rod brakes, where the brake shoes rub on the inside circumference of the rim. The Westwood profile has a ridge between the braking surfaces. The spoke holes are drilled into this ridge, and the ridge protects against the brake shoes hitting the nipples.

Westwood rims are most commonly seen in the 635 mm (28 x 1 1/2) size, but they were made in most of the middleweight British sizes.

Whatton Bars

Handlebars located below the seat of a U.S.S. recumbent.


A hub, rim, and spokes all together; may also include the tire and tube.

Wheel Base

The distance from the center of the front wheel to the center of the rear wheel. In general, a bicycle with a longer wheel base is more stable and comfortable; one with a shorter wheel base tends to be more maneuvrable. See: angles.

Wheel Goods

Bicycle/toy industry term referring to ride-on wheeled toys, such as scooters, little red wagons, pedal cars, etc.

Wheel Retention


Wheel Sucker

A cyclist who drafts other cyclists without taking his or her share of pulling.


A wheelie is the act of using a combination of pedal thrust and weight shifting to raise the front wheel into the air. A skillful freestyler can lift the front wheel high enough that the center of gravity moves over the rear wheel, then ride the bicycle as if it were a unicycle. The correct verb to describe the act of doing a wheelie is "pop". Wheelies often cause great stress on a bicycle's fork when the front wheel comes back down.

A "nose wheelie" results when the front brake is applied hard enough to cause the rear wheel to lift off.

Wheelie Bike

Also known as a "high-riser", "Stingray", "polo bike", "banana bike", "Chopper". The most horrible children's bikes ever made. Some who had them as children retain a sentimental attachment to them, so there is an active market in "collectible" wheelie bikes, but they were, in my considered opinion, an unmitigated disaster.

Early wheelie bikes were home made by adapting a bike made for a small child for use by a larger child. They would use a frame from a 20" wheel child's bike, install tall "ape hanger" handlebars and a "banana seat" which extended back over the rear wheel. The resulting weight distribution created a bicycle that would do a wheelie with the slightest effort.

The American bicycle industry, led by Schwinn with it's "Stingray" and "Krate" models, jumped on this early '60's fad. They made a lot of short-term profit, but, I believe, this led to a serious long-term setback for the American bicycle industry.

Before the wheelie bike craze, there was a well-established progression of frame sizes for growing children, from 16", to 20", to 24" and finally to 26" wheel bicycles. The wheelie bike killed the 24" bike market, because these bikes would sort-of fit children who should really have been riding on 24" wheels.

Wheelie bikes also greatly re-inforced the idea that the bicycle was a child's toy, not a serious vehicle. Wheelie bikes were easy to do wheelies on, but their awkward riding position made them hellishly uncomfortable to actually ride more than a half-mile at a time.

Wheelie bikes in turn were killed by BMX bicycles, which are much more "rideable", but the 24" market never completely recovered.


Sir Joseph Whitworth was one of the great inventors of the 19th century. He invented the milling machine, and was the first to manufacture all-metal machine tools. I believe that he was also connected with the Rudge bicycle company (later acquired by Raleigh).

He was also one of the first to establish a standardized set of screw threads and wrench sizes. Whitworth fasteners were used in British industry up until the late 1960's, when Britain adopted the metric system. The Whitworth system is now virtually extinct.

Whitworth fasteners used a 55 degree thread angle. The wrench sizes were confusingly marked, the wrenches are all larger than you would think. This is because the dimension given on a Whitworth wrench is the diameter of the bolt thread usual for that size wrench, rather than the size of the head. Some Whitworth wrenches even have two marked sizes, because the same head size is used with one coarse thread and a different diameter fine thread.

Some of the smaller sized Whitworth threads are interchangeable with S.A.E. threads.


Wishbone type frames have seat stays that do not run all the way up to the seat cluster. Instead, there is a single tube running from the seat cluster down to where the brake bridge would normally be. The seat stays come up and join this tube, much as the blades of a unicrown fork join the steerer. The advantage usually given for this type of construction is that it provides a more solid mounting for cantilever brake studs, since there is only a short length of narrow seat stay above the stud.

Wooden rims

In many ways, wood is an ideal material for bicycle rims, and most bicycles in the early part of the century were equipped with them. They are light, strong, and resilient. Wood rims are not suitable for "clincher" tires, but worked well for other types.

Wooden rims went out of style for road bicycles when rim brakes came in, but continued to be use on the track well into the '40's. They were eventually outlawed for competition because of their dangerous failure mode: When a highly-tensioned racing wheel with a metal rim was damaged, it would fold up, but it would stay together. Similar wood-rim wheels, when overstressed, would suddenly turn into a cloud of sharp, dangerous splinters.

Woods Valve

There is a third type of valve, very rarely seen in the U.S., which has a bottom similar to a Schrader and necks down to about the size of a Presta. This is a Woods valve, also known as a "Dunlop" valve. Woods valves were formerly popular in the British Isles and Asia. You can pump them up with a Presta pump.

Woods Schrader Presta
Woods valveSchrader valvePresta valve
Older versions work with rubber tubing and spit. If they don't hold air, you can unscrew the knurled ring that holds the valve core (the "Presta-sized" part) in place. You should see a short length of rubber tubing covering the inner part of the core. If the rubber tubing it old and perished, the valve won't work. Some patch kits include short lengths of replacement rubber tubing for this purpose. When installing new tubing, lubricate the valve core with spit before slipping the tubing in place.

Newer versions use a modern spring-loaded valve mechanism.


A tool for turning nuts or bolts. This term is not common in British usage, where the term "spanner" or "key" is generally preferred.

Wrenches are divided into two families:

  • Fixed Wrenches are made of a single piece of metal, and only fit specific sizes of fasteners. Fixed wrenches are made for different sizing systems, including Metric, S.A.E., and Whitworth. Types of fixed wrenches include:

    • Box Wrenches have a complete loop that surrounds the fastener. They are substantially stronger than open-end wrenches, and are the best use for high torque applications, both because the wrench is stronger, and because it can contact more than two corners of the fastener.

    • Combination Wrenches are double-ended wrenches with an open end and a box end, usually for the same size on each end. This is the most useful and most common general-purpose wrench style.

    • Open-end Wrenches have ends shaped like a two-tined fork. They normally have two parallel surfaces which bear against two of the sides of a fastener. Open-end wrenches are faster to put on to fasteners, and are the only kind that can be used where there is not clearance to slip a box wrench over the end of the fastener.(cone wrenches, headset wrenches, pedal wrenches and spoke wrenches)

      Bicycle applications often call for special-purpose open-end wrenches:

      • Cone wrenches and headset wrenches differ from normal open-end wrenches in that they are thinner than usual for a given fastener size.

        I have an article about Cone Wrenches in my Tool Tips series.

      • Pedal wrenches are thin open-end wrenches with heavy-duty jaws and extra-long handles.

      • Spoke wrenches have taller contact areas than most wrenches and have short handles for use in the close quarters between spokes.

    • Socket Wrenches, similar to box wrenches, surround the fastener. Unlike box wrenches, the outside of the head of a socket wrench is circular so that it can reach a fastener which is recessed into a hole. A socket wrench may have an offset handle, as with a peanut-butter wrench, but more often, the handle will attach to one end of the socket.

      Most socket wrenches are part of modular systems, and have interchangeable handles available, including ratchet handles, torque-wrench handles, extensions, breaker bars, and screwdriver-type handles.

      6 Point vs 12 PointSocket and box wrenches for hex fasteners come in two types, 6 point and 12 point.

      12 point is good for box wrenches, because it gives you twice as many possible orientations to put the wrench on the fastener. This is especially good for working in close quarters, but is rarely an issue on bicycles. 6 point wrenches are stronger and less likely to slip. Generally, 6 point would be preferable for bicycle work when you have a choice.

    • Nutdrivers are smaller sized socket wrenches with screwdriver type handles. These are often faster to use than conventional wrenches, and the screwdriver-type handle makes it unlikely that you'll strip the threads of a smaller nut or both. 8 mm, 9 mm and 10 mm nutdrivers are among my favorite bike tools. They usually have a hollow handle so they can even be used to run a nut down a long bolt.

      I have an article about Nutdrivers in my Tool Tips series.

    • Spanner Wrenches use pins to engage holes or notches in the fastener.

      • Pin spanners usually use two pins which fit into a pair of holes in the surface of a fastener. Common bicycle applications for pin spanners include adjustable bottom-bracket cups and freewheel bearing cones. Some crank dust caps and headset lock nuts also use pin spanners.

      • Hook spanners have an end shaped a bit like a capital "G". They wrap around a round fastener and the tail of the "G" fits into one of several notches on the fastener. Hook spanners are commonly used on bottom-bracket lockrings and track hub lockrings. They are also used on some headsets.

    • Allen Wrenches are hexagonal wrenches that fit into the matching hexagonal holes of Allen bolts.

    • Spline Wrenches (including Torx, freewheel, etc.)

  • Adjustable Wrenches can be adjusted to fit different sized fasteners, usually by the use of a thumb screw. They don't fit as well as the correct size fixed wrench, so good, well equipped mechanics only use them as a last resort.

    I have an article about Adjustable Wrenches in my Tool Tips series.

    • Crescent ® Type Wrenches. Although "Crescent" is a trademark, it is commonly used in the U.S. to refer to a normal, angled head adjustable wrench regardless of brand. The jaws are set at a 30 degree angle to the handle to allow them to be used in tight quarters.

    • Monkey Wrenches have their jaws perpendicular to the handle. They commonly open up much wider than crescent-type wrenches.

    • Pipe Wrenches are similar to monkey wrenches, except that they have serrated jaws, which are designed with a bit of play which causes them to grip more tightly when turned in the appropriate direction. Pipe wrenches are primarily used for plumbing, generally have no bicycle application.

    • Adjustable pin spanners fit a range of different pin spacings. The spring-loaded Park SPA-1 (green) adjustable pin wrench is the most useful one for most adjustable bottom-bracket cups.

    Wrenches are sometimes confused with pliers, and naive users sometimes try to use pliers for jobs that really require a wrench. This usually results in damage to the nut or bolt so abused. It can also cause failure due to undertightening the part involved.
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