the_custom_bicycle

RECOMMENDED BRAZING PROCEDURES

area of the tube. Overheating will lead to burning or to brass inclusion (where the molten brass or bronze enters the grain of the steel), either of which will make the tube brittle.

6.Setting, when necessary, should always be done cold.

7.Most proprietary brazing materials can be used satisfactorily, but we recommend the use of brazing materials with a melting point of about 850°C. (1,562°F.).

APPENDIX IV

Bottom

Bracket Width

APPENDIX V

Chain Lines

THE CUSTOM BICYCLE

Tandem Chain Line

_a

Chain Line

JT2.5

-b

aTrack Right-hand Standard Crank

bTrack Right-hand Crank with Left-hand Thread

25.4

c Track Left-hand Crank with Right-hand Thread

Glossary

Agrati—an Italian company that produces many frame-building parts such as bottom brackets, lugs, and dropouts.

anodized—metal subjected to electrolytic action to coat it with a protective and/or decorative finish.

baking oven—a large structure with variable temperature controls that is used to bake paint finishes on bicycle frames.

balloon tire—a tire 2 or more inches wide with a low pressure capacity.

bearing race—the circle that the balls in bearing cones and cups make as they contact the axle.

Bivalent hub—a Cinelli-designed hub for bicycle wheels. Bivalent hubs permit a quick rear-wheel change since the freewheel remains with the frame—not with the hub. Front and rear wheels are interchangeable. Unfortunately, because of high production costs, Cino Cinelli has withdrawn the hubs from the market.

bottom bracket—a short round tube on a bicycle frame to which the down tube, seat tube, and chainstays have been brazed or welded.

bottom bracket cup—a part of the bottom bracket bearings that screws into the frame's bottom bracket and in which the crank axle's bearings run.

bottom tube (on tandem)—tube connecting the two cranksets.

brazing—a process by which two metal surfaces are joined by means of heating and melting a third substance such as brass or silver.

brazing with pins—the use of "nails" in frame construction to keep the tubes in the proper position in the lugs.

bronze brazing—melting bronze in order to join two metal surfaces that have higher melting temperatures than the bronze.

THE CUSTOM BICYCLE

Brox—French brazing material used in frame building.

butted tubing—catchall term given to all tubes that are either double butted, single butted, or taper gauge.

a.double butted—refers to a tube that is thicker at the ends than in the middle without an increase in its outside diameter.

b.single butted—same as double butted, except only one end is thicker.

c.taper gauge—refers to a tube whose thickness is gradually diminished through highly mechanized industrial operations. Forks are always either taper gauge or straight gauge; they are never double butted or single butted.

Campi—term used when referring to components made by S.P.A. Brevetti Internazionali Campagnolo.

carbon fiber—a chemical term which refers to a composite of fibers of a pure element, in this case carbon, that are woven and distributed randomly and are bound together to form a strong lightweight material.

cast bottom bracket—a bottom bracket that is formed in a mold and, as a result, does not have a seam.

caster—a word used interchangeably with tail and trail. Caster angle is formed by the intersection of a vertical line drawn through the front fork ends and a line which is parallel to the head tube and is extended to the wheelbase.

cast lug—a bicycle lug that is formed in a mold and, consequently, does not have seams.

Castolin—a brazing material with about 40 percent silver produced by the Swiss firm, La Castolin Societe Anonyme of Lausanne.

cast seat lug—seatpost lug molded to precision.

century—100-mile ride.

chainstays—two tubes which go from the bottom bracket to the reardropouts.

chrome plating—applying a thin coating of chromium on frames or other bicycle parts.

cold setting—aligning frame while it is cold (after brazing).

Columbus—Italian-produced special frame tubing.

cone and locknut—bearing parts that attach to axle on which

bearings run around. The nut is screwed down hard on another nut to prevent slacking back.

Continental fork section:—refers to wide oval fork blades.

copper-tacked or coppered—initial step in frame-building procedures in which tubes and lugs are held together by torching copper.

crankarm—rotating portion which holds the pedal.

criterium—a multilap road race that is held on a short circuit varying in length from one to ten miles. The criterium course utilizes public roads that are temporarily closed to normal traffic. This race is designed to allow the spectator to see the riders as they pass by each lap.

custom frame—bicycle frame that is built by an artisan to fit the various needs of the individual customer.

cyclo-cross—cross-country race event on special course featuring obstacles.

derailleur—a mechanical device that is bolted to the bicycle frame. Its purpose is to shift (or derail) the chain from one gear to another, allowing variable gear ratios.

down tube—that part of the bicycle frame which connects the bottom of the head tube with the bottom bracket.

drop-forged handlebar stem—stem made from aluminum alloy and forged to shape under high pressure.

dropouts—slots into which the front and rear wheels fit.

ergonomics—biotechnology or the application of biological and engineering data to problems related to man and machine.

faced bottom bracket—edges of the bottom bracket are faced with a special tool to make sure that they are squared.

facing—squaring edges with a special tool.

flash-weld—using heavy electrical current at high speed and frequency to weld tubes.

flat top crown—a fork crown on which the top part is flat.

fork—that part of the bicycle that holds the front wheel in place and is attached to the frame by the headset. The fork assembly includes a fork steering column, a fork crown, fork blades, and the fork dropouts. There are three types: semi-sloping, fully sloping, and flat.

THE CUSTOM BICYCLE

fork blades—curved tubes that connect the fork crown to the front dropouts which hold the front wheel in place.

fork crown—that part of the fork that attaches the fork blades to the fork steering column.

a.stamped or pressed—fork crown which has been cut, bent, and stamped into shape by a die.

b.forged—a fork crown that is produced with the grain of the steel "in line" by heating and hammering with highly refined machines.

c.cast—similar to the cast lugs and the cast bottom bracket, the cast fork crown is formed in a mold and, as a result, does not have a seam.

fork rake—each bicycle fork is bent or curved on the bottom, just before it attaches to the fork dropouts. The fork rake is the amount the tube is bent.

freewheel—a mechanism with one, two, three, four, five, six, or even seven individual sprockets with varying numbers of teeth on each sprocket. The freewheel threads onto the rear hub and, together with the chain and crankset, permits the rider to propel his bicycle. The various number of teeth on the freewheel sprockets determines the gear ratios for a particular bicycle. The name "freewheel" is given to this gear mechanism because it is built to enable the rider to coast when not pedaling, as opposed to a direct-driven mechanism which requires the cyclist to pedal all the time.

front-wheel expander brake—brake with a hub shell and an internal expanding brake shoe.

gear ratio—To calculate a gear ratio, multiply the diameter of the wheel in inches by the number of teeth on the front chainwheel and then divide by the number of teeth on the rear sprocket. For a 10-speed these calculations must be done ten different times; once for each of the different chainwheel/ freewheel sprocket combinations. Gear ratios can also be calculated in meters.

glass beading—cleaning the surface of a metal with tiny glass beads propelled by a jet of compressed air.

Haden blank—an oversize lug manufactured by Haden Brothers, Limited, of Birmingham, England. It is intended for the builder who wishes to file the lug to a final shape that varies from those commercially available.

GLOSSARY

hanger bracket—another name for bottom bracket.

head angle—refers to the angle which is formed by drawing a straight line through the head tube to the ground.

headset—parts of bearing mechanism in the head tube that secure the fork to the main triangle.

high-wheeler—bicycles of the late 1800s with large-diameter front wheels (approximately 50 inches) and smaller-diameter rear wheels (approximately 17 inches), straight handlebars, and spokes radiating directly from the hub (no crossover); vehicle was mounted via a small step above the rear wheel.

hot setting—aligning frame while it is still hot.

investment cast lug—mold is made of lug to precision then filled with wax. The wax is melted out, leaving the mold to be filled with the material for the lug.

Italian section fork—a term synonymous with the large, sectioned fork blades.

jig—a metal fixture that firmly holds various frame parts while the builder brazes them together.

lug—metal sleeve that holds the frame tubes at the joints.

lug cutout—designed pattern that is incorporated into the lug.

main triangle—that part of the frame which is made up of the head tube, top tube, seat tube, and the down tube.

mandrel—a spindle or metal bar around which tubes are shaped.

mass start race—any race on either the track or road where the competitors start at the same time.

microfusione—term used in describing investment cast products.

mitered tube—a tube which has been precisely cut so that the entire diameter of the tube sits flush against the tube it butts up against.

Nervex—the brand name of quality lugs, bottom brackets, and fork crowns produced by the French company Ets. Aime Dubois in Yssingeaux, France.

pannier—saddlebag that is mounted on a bicycle by means of a carrier over the rear or front wheel. It is generally constructed of heavy-duty canvas or reinforced nylon.