Glossary

Alloy – a silly term that is mistakenly used in the cycling business as a replacement term for aluminium. An alloy is a mixture of metals – brass is a copper/zink alloy, steel is an iron/carbon iron/vanadium etc alloy. Stainless steel is an alloy of iron and chrome.

Butting – good quality spokes are butted at both ends and therefore known as double-butted spokes. A more accurate term would be swaging, but the industry has settled on butting and cannot be budged on that one. The butt refers to the thicker part of the spoke. Bicycle frame tubes are butted where they are to be welded. Triple-butted is a little confusing since a spoke only has two ends. A triple butt is nothing more than a very pronounced double-butt.
Cross pattern – the number of spokes crossed by another spoke in the lacing pattern. Expressed as 2X or 4X. The less spokes in the wheel, the less the number of spokes you can cross practically.
Dish – the difference in spoke angles on rear wheels. Modern 9- and 10-speed bicycles require a severe dish that effectively weakens the wheel and increases wheelbuilding challenges. Front wheels (with the exception of disk-braked wheels) have no dish.
Rim brake – the use of a brake calliper that closes directly on the rim. This is used on all racing bikes and less and less on mountain bikes.
Disk brakes. Also a calliper type brake, but the disk pads closes on a disk (called rotor in America) mounted on the hub. Disk brakes affect wheel build and spoke length because they require dishing.
Drag brake – a special hub-brake of the drum variety for use on tandem rear wheels. Good tandem hubs have a thread on the left side for attaching a drag brake.
Eyelet – a steel (hopefully stainless steel) reinforcement at the spoke hole in a rim.

Gall – seizing of moving metal parts due to high friction and lack of lubrication. In wheels, nipples sometimes gall on the spoke thread. 
Gauge – an old-fashioned unit of measurement for wire thickness. Nowadays we measure spokes in SI units i.e. mm.
Head – the mushroomed end of a spoke
Hop – a radially out-of-true area on the rim.
Hub flange – the part of a hub which is drilled to accept spokes.
Hub spacing – the distance between left and right flange on the hub’s axle. Front hubs are all spaced at 100 mm. 7-speed bikes have a 120mm rear spacing and modern bikes up to 135mm (for mountain bikes). Tandem spacing is 140 or 145 mm with some tandems going up to 160 mm.
Lacing – the route in which the spokes travel from hub to rim.
Nipple – special nut that tensions a spoke and attaches it to the rim (sometimes to the hub).
Radial lacing -  a spoke pattern without any spokes crossing each other and each spoke exits and enters at a right angle from and to the hub and rim. Cannot be used on rear Rim – the round hoop supporting the spokes and tyre. On all good quality bikes, this is made of aluminium. On silly bikes a rim could be made of carbon, a material that creates more problems in rims than it solves.
Rim tape – don’t forget the rim tape, an important strip of plastic that protects the tube from the spoke cavities in the rim.
Rim transplant – replacing a damaged rim with an identical new one without disturbing the spokes.
Straight-gauge – a spoke without any butting.
Stress relieve – applies to spokes in this instance. It is the process of removing all residual stresses from spokes which were left behind from the manufacturing and building process. Stress relieving during building prevents fatigue failures later in the spoke’s life.
Shaft – the centre part of a spoke
Socket or double-eyelet – a type of eyelet that pulls on both the internal and external wall of the rim. It makes for a better and stronger rim and is preferable at all times.
Spoke count – the number of spokes per wheel. 28 is considered low, 48 is considered adequate for a tandem rear wheel.
Threaded side – the end of a spoke where the nipple screws on.
Torque transfer – the transfer of turning force from the rear hub’s right side to spokes on the left hand side. Torque transfer is a function of hub diameter and slender hubs therefore transfer very little torque from right to left. This doesn’t make them bad, since the rotating force is transferred to the rim  via the spokes.
wheels or with disk brakes since it transfers no torque.
Torsion -  Twisting stress in a material. Torsion should be completely absent in a well-built wheel. The spokes should therefore have no wind-up once the wheel is finished. A skilled wheelbuilder knows how to eliminate torsion, yet apply lots of tension to the spokes. A spoke that is both in tension and torsion, easily breaks at the shaft, the thinnest part of the spoke and can shoot out of the wheel like an arrow. Torsion is to be avoided.
Tubeless rim – a rim with an airtight rim tape and valve attachment. On mountain bikes, standard rims can be converted to tubeless rims with the use of a special rim strip and attached valve.
UST – Universal System Tubeless. A type of rim with special rim tape that makes it airtight. The UST standard was set by two French companies, Mavic and Hutchinson and is widely licenced to other manufacturers. UST tyres are slightly heavier than tubed tyres because there is more rubber in them for keeping them airtight.
Wobble – a lateral out-of-true area on the rim.