| Tools |
| Gear Calculator | Calculate Ratios, Rollout, Speed, etc |
| Gear Comparer Tool | Compare two gear sets and recieve a detailed listing of differences
(Version 1.0) |
| Fork Geometry Calculator | Calculate Rake, trail, offset, and other aspects of the front forks
(Beta Version) |
| Spoke Calc Lite | Web Based Spoke Calculator
(Coming Soon) |
| Spocalc | Spocalc is a Excel based spoke length calculator. Link goes to the SheldonBrown.com page about this calculator |
| Restoration & Wrenching Articles |
| Restoration | Author | Added | |
| Mothers Alum and Mag Polish on Hubs | Jon Fischer | 7/28/2007 | |
| Wrenching | Author | Added | |
| Methods & Tips on Mounting Tubular Tires | Jon Fischer | 8/14/2007 | |
| Modern Component Groups on Vintage Frames | Jon Fischer | 7/25/2007 | |
Measurement of BCD is found by measuring from center to center of two adjacent holes:
Multiplying this dimension by 1.7 will give you the actual BCD for a 5 bolt chainring, multiply by 1.4 for 4 bolt chainrings
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| BCD Reference Table (5-hole rings) |
| BCD (mm) | Smallest Ring | C-t-C (mm) | Application |
| 151 | 44 | 88.8 | Pre-67 Campagnolo Standard |
| 144 | 41 | 84.6 | Old Campagnolo Standard, some current track cranks |
| 135 | 39 | 79.5 | Modern Campagnolo Standard |
| 130 | 38 | 76.4 | Road Double and Triple Outer 2 rings. Most Shimano Road |
| 128 | 38 | 75.2 | Nervar Cranks |
| 122 | 38 | 71.7 | Stronglight 93 and similar |
| 118 | 36 | 69.4 | Ofmega, SR |
| 116 | 35 | 68.2 | Old Campagnolo Standard |
| 110 | 33 | 64.7 | Touring double, Standard triple outer rings |
| 94 | 29 | 55.4 | Compact triple outer |
| 92 | 30 | 53.3 | Shimano Dura-Ace triple inner ring |
| 86 | 28 | 50.5 | Stringlight 99, some SR triples |
| 74 | 24 | 43.5 | Standard triple inner ring, paired with 110, 130, 135mm |
| 56 | 20 | 32.9 | SunTour compact |
| Crankset Type | Threading / BB Width | Spindle Length | Cup Type |
| NR/SR Double 77-87 | BSC 68mm | 114.5mm | Thick Cup |
| GS Double 77-87 | BSC 68mm | 114.5mm | Thin Cup |
| NR/SR Double 77-87 | French 68mm | 114.5mm | Thick Cup |
| GS Double 77-87 | French 68mm | 114.5mm | Thin Cup |
| NR/SR Double 67-77 | BSC 68mm | 112mm | Thick Cup |
| Pre-78 GS/Record | BSC 68mm | 112mm | Thin Cup |
| NR Double 67-77 | French 68mm | 112mm | Thick Cup |
| Pre-78 GS/Record | French 68mm | 112mm | Thin Cup |
| NR Triple 77-87 | BSC 68mm | 123mm | Thin Cup |
| NR Triple 77-87 | Italian | 124mm | Thin Cup |
- For Italian double ring BB spindles, add 1 mm to BSC/French lengths. Record ("NR") and SR all use the same arms at any given time in history. An SR crankset only has different chainrings than Record. Otherwise, they are identical. BBs are not!! There are four types: GS, Record, Nuovo Record, and Super Record (Ti spindle, Alu cups).
- Use of pre-78 cranks on post-77 spindles will result in cranks sitting 1.5 millimeters too far outboard.
- From 1958 - 1972 Record crank arms were not dated on their back side
- From 1973 - 1979 the year of crank manufacture is the last digit in a diamond
- From 1980 - 1984 the year of crank manufacture is the last digit in a circle
- "11" in a rectangle means 1985, "22" means 1986, and "33" means 1987
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| Bicycle Part Standards |
| Handlebars |
| Clamp Diameter | Application |
| 22.2 mm or 7/8" | Steel bars on BMX or old MTB |
| 23.8 mm or 15/16" | British Steel bars: often on old 3sp or drop bars |
| 25.4 mm or 1" | Standard ISO size. Many vintage bicycles sold in the US used this size |
| 25.8 mm | Unoffical in-between size produced to fit either 25.4 or 26.0 |
| 26.0 mm | Italian Standard for drop bars. |
| 26.4 mm | Cinelli Standard up till 1998 when they moved to 26.0 |
| 31.8 mm or 1 1/4" | Modern oversized Road standard |
| Bottom Bracket Threading |
| Standard | Threading | Adjustable Cup Thread | Fixed Cup Thread | Shell Width | Notes |
| British/ISO | 1.370" x 24 tpi | Right | Left | 68mm | British/ISO are interchangable |
| Italian | 36mm x 24 tpi | Right | Right | 70mm | Fixed Cup Prone to unscrewing itself |
| French | 35mm x 1mm (25.4 tpi) | Right | Right | 68mm | Fixed Cup Prone to unscrewing itself |
| Swiss | 35mm x 1mm (25.4 tpi) | Right | Left | 68mm | Same as French but Left threaded fixed cup |
| Rear Drop-out Spacing |
| Width | Cog # | Notes |
| 120mm | 5sp, 6sp Ultra | Standard spacing for 10-seed road bikes up till early 80's |
| 126mm | 6sp, 7sp | Standard spacing for road bikes during the mid 80s through early 90's |
| 128mm | 6sp, 7sp, 8sp | Transition Spacing, not an offical standard. Some bikes were built with a spacing of 128mm to accept either 126 or 130mm wheels. |
| 130mm | 7sp, 8sp, modern 9/10sp | Current modern spacing for rear wheels starting with 8sp. Some 7sp bikes also were speced with a 130mm rear |
| Notes |
A steel bicycle frame can be cold set from a smaller spacing to a wider one by one of several different methods. Usually it is only advisable to go from 120 to 126 or 126 to 130mm. Spreading the dropouts too far can cause damage to the frame in the form of breaking bonds at the brake bridge or similar problems.
See the Glossary term Cold Setting for details on how to cold set a bicycle frame.
Note: You Should Never attempt to cold set frames made of aluminum, carbon fiber or 753 steel.
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