1 Newton = .2248 pounds

An unofficial metric unit of force is the kilopond or "kilogram of force." This is the force exerted by the weight of a 1 kilogram mass in normal earth gravity, and is equal to 9.81 Newtons or 2.2 pounds.

The "kilogram of force" is a disreputable unit, abhored by pedantic purists. Nevertheless, it is commonly used in the bicycle industry, particularly when dealing with spoke tension, since the most popular tensiometer is calibrated in these units.

This site includes a Nexus Gear Hub Technical Page and an on-line version of the Nexus 8-speed Service Manual.

In fact there is no such standard gear numbering system, nor should there be, because some gears put the chain at bad angles, and should not be used.

I know of 4 different "systems" for numbering the gears of a 10 speed:

1. The 5 gears using the small chainwheel are 1-5, those that use the large chainwheel, 6-10

2. The 5 gears using the small chainwheel get the odd numbers 1-3-5-7-9, large 2-4-6-8-10

3. The gears can be ranked numerically by how high each gear is. The pattern would then depend on the sizes of the sprockets involved.

4. I used to know an engineer who used a variation on the previous system: He plotted everything out on semi-logarithmic graph paper, and came to the conclusion that his 10 speed was actually a 12 speed that was missing 2nd and 11th. He numbered his gears 1,3,4,5,6,7,8,9,10,12.

When discussing issues related to the function of the derailers, it is better to refer to "the second largest rear sprocket" or "the middle chainwheel".

When discussing issues related to the biomechanical aspects of gearing, it is better to use terms that relate to the actual ratios, such as gain ratio, gear inches or development.

Of all the things bicycle mechanics do, adjusting spoke nipples is the one that requires the most skill and experience. If you wish to learn more about this process, see my article on Wheelbuilding.

They have very strict standards, with the intention of preventing mechanical failure and "leveling the playing field" among the athletes.

Not all of the N.J.S. standards actually relate to quality as such, but rather act to promote interchangeability of parts and tools.

N.J.S. threading and sizing standards are generally the same as Campagnolo track parts.

This design was formerly associated with the North Road Cycle Club, north of London. It is a reversible design, most often used in the upright position, but quite serviceable in the dropped position as well, for a more agressive riding position. In the reversed position, it resembles a Moustache handlebar, but with sharper bends and a bit more drop.

Octalink ® cranks come in one of two different spline patterns:

• The original "V1 " type for:
  • XTR (BB-M952 9-speed) 112.5 & 116 mm lengths
  • Dura-Ace (BB-7700 9speed) 109.5 mm (double) & 118.5 mm (triple) lengths
  • Ultegra (BB-6500 9-speed) 109.5 mm (double) & 118.5 mm (triple) lengths
  • 105 (BB-5500 9-speed) 109.5 mm (double) & 118.5 mm (triple) lengths
• The later "V2" type for:
  • Deore XT (ES70/71)
  • Deore LX (ES70/71)
  • Deore (ES50/51)

    The V2 BBs work with FC M752, FC M751, FC M572, FC M571, FC M510-8 and FC M440-8 cranks.

  • Tiagra 2005 (4401,4404)
  • Sora 2005 (3301,3304)

• O.E.M. pricing is the lowest possible price structure, since the parts are sold in the largest quantities.

• O.E.M. packaging is less expensive per unit, because hundreds of parts are packed in a single crate, with little or no internal packaging material.

• O.E.M. parts are often cheaper versions of parts sold to the aftermarket, even though they may have the same model designation.

One piece, or "Ashtabula" cranks are heavy but very strong and reliable. They are also much easier to work on than any other type of crankset, requiring no special tools. You can completely overhaul a one-piece-crank bottom bracket with just a large adjustable wrench and a screwdriver.

There are two different threadings used on one-piece cranks. Most are 24 threads/inch, but some, notably older Schwinn and Mongoose bicycles, used 28 tpi. The bearing retainers and cups are also slightly different between the two models. Although they both use 5/16" balls, 24 tpi units use a #66 retainer with 10 balls, while the 28 tpi units use a #64 retainer, with 9 balls. This is one application where retainers are essential, it is almost impossible to assemble a one-piece crank bottom bracket with loose balls.

One-piece cranks only fit in bicycles designed for them, with large-diameter, threadless bottom brackets. It is possible to buy adapter kits to allow three-piece cranks to be used in this type of bottom bracket shell.

One-piece cranks are made in a smaller diameter than other crank designs, so that the bearing cones can be installed. As a result, they have to use a smaller diameter (1/2" x 20 tpi) pedal thread.

The left side cone has a left thread, and uses a lock nut and keyed washer to secure the adjustment. The right side cone has a right thread, and secures the chainwheel to the crank.

See my article on One-piece Cranks.

• Only The Best, a bicycle brand sold by Charlie Hamburger in Boston, 1940s-'50s.

• Off The Back, i.e. left behind by the peloton, out of the race.

• Over The Bars, usually resulting from a head-on collision.

Back in the 1890s, this term made sense, but using it nowadays is silly and only causes confusion.

Traditional forks used 1" (25.4 mm) diameter steerers. Oversized steerers are 1 1/8" (8.6 mm) or, less commonly, 1 1/4" (31.8 mm). Details on sizes are listed under headsets.

Traditional frames used 1" (25.4 mm) top tubes, 1 1/8" (28.6 mm) seat tubes and down tubes, and 1 1/4" (31.8 mm) head tubes. When BMX racing became popular, frames built to these old standards couldn't always hold up to the rigors of BMX competition. Since the wide availability of T.I.G. welding freed designers from the need to use tubes that would fit standard-size lugs, oversized tubing became the norm for BMX frames. This design and technology was later adopted by builders of mountain bikes.

In the interest of improved chainwheel/tire clearance, some mountain bikes have "oversized" bottom brackets, with a shell width of 73 mm, rather than the standard 68 mm.