Lochkreisdurchmesser von Kurbeln (Tabelle)
Bicycle chainrings have between three and six bolt holes to attach them to the crank, spaced around in a circle. The table below gives bolt-circle dimensions for the main brands using each bolt pattern. Aftermarket and less prominent brands tend to use the same bolt-circle patterns as the main brands, for compatibility.
Direct measurement of the bolt-circle diameter is often not possible with a ruler. No two of an odd number of holes are directly opposite another. A protruding part may prevent direct measurement of the bolt-circle diameter of a crank spider. So, this page lists spacings between bolt holes which are not opposite one another, and these identify the bolt-circle diameter.
Many references describe distances between bolt holes as "center to center," but there is only empty space at the center of a hole! D'oh! Measuring from right side to right side or left side to left side is more reliable -- as shown in the photo below.
Measuring between two adjacent bolt holes
Measuring between non-adjacent holes reduces the likelihood of mistakes when differences are small. As an exercise, you may check the dimensions in the table farther down this page to identify the chainring in these photos, and then double-check against the brand-name stamp on the chainring.
Measuring between non-adjacent bolt holes
The bolt-circle diameter doesn't tell the whole story about compatibility if you mix and match parts. Sometimes you can fix the problem by installing a chainring inside-out or using washers to adjust spacing. Check for these issues:
Most 4-bolt and 5-bolt chainrings have 10mm bolt holes, though some have 8mm or are threaded.. Most 3 and 6-bolt chainrings have 7-9mm bolt holes. The stack of chainring(s), crank spider and washers must be thick enough that bolts and sleeve nuts tighten up against the chainring(s), not against each other. A problem most commonly occurs when using a single chainring with bolts and sleeve nuts made for a double. You may have to invert the chainring so bolt heads do not sit in recesses, or add a washer under the flange of the sleeve nut. The teeth of a chainring may be toward the inside, the outside, or in between. Shifting is smoothest if teeth of an outer chainring are toward the inside, or the inside face has a smooth taper approaching the teeth, so the chain can engage a tooth when upshifting: A chainring with teeh alternating wide and narrow is usable only on a single-chainwheel system, as the chain may not land correctly after derailing. Most chainrings pull chain equally well in either direction. Some have specially-formed teeth made to pull only in a single direction. A chainring for narrower chain can work with a wider one, but spacing between chainrings may need adjustment for the best shifting. Chainrings for wider chain may work with slightly narrower chain, but this chain may require closer chainring spacing for clean shifting.. Ramps and pins on chainrings improve shifting with chainrings designed to work with each other. Chainrings without ramps and pins shifted better with old-style chains with protruding rivet pins.
After measuring BCD, you might check Wolf Tooth's Road and MTB chainring entries for details on newer 4- and 5-bolt chainrings; also RaceFace's compatibility table. Wolf Tooth also offers a guide to direct-mount (spiderless) chainrings at the bottom of a page on its Web site..
All bolt-circle patterns used to have bolt holes equally spaced around the bolt circle. Starting around 2010, manufacturers introduced patterns with unevenly-spaced holes. These allow bolt heads of a small-diameter pattern to clear a thick crank, and enforce chainring orientation, important with ramps and pins. Unevenly-spaced bolt holes make it impossible to turn chainrings to increase wear life, and some patterns reflect mere cussedness -- "brand lock". Please see the page at pardo.net discussing technical, pricing and availability issues for chainrings with unevenly-spaced bolt holes.
Bolt-hole spacing dimensions here for evenly-spaced holes reflect exact (known) angles. We have given dimensions reflecting an integer number of degrees, probably correct, for unevenly-spaced holes. Measured angles for all Shimano unevenly-spaced holes were so near 70 and 110 degrees that our numbers are almost certainly correct. SRAM had to be different, and its angles appear to be 72 degrees (same as with a 5-bolt chainring) and 108 degrees. Wolf Tooth and FSA sell chainrings to fit other manufacturers' cranks but also chainrings that fit only their own cranks and direct-mount spiders.
We are working on a Web page with more observations, and a description of how we generated the numbers in the table below. If you can provide corrections or additional information, please do! A Microsoft Excel workbook with calculations of all the dimensions used on this page is available on this site.
Many thanks to Ulrik Hansen for updates to the 4-bolt crank list.
4-bolt, even spacing 4-bolt, uneven spacing 5-bolt 6- and 3-bolt
4-Bolt Cranks/Chainwheels, even spacing: For uneven spacings, see the next section of this table. Beware of near-matches! Measure! The BCD is 1.414, 1/sin 45°, times the spacing between adjacent holes. BCD (mm) Smallest Ring Between adjacent holes (mm) Application 146 44 103.2 Shimano XTR M960 Hollowtech 4-arm outer. 145 44 102.5 Campagnolo Super Record, Record, Chorus 120 36 84.9 SRAM 2 x 10 and XX. Threaded. 112 34 79.2 Shimano XTR M950, M952 4-arm middle/outer, Campagnolo inner. 110 34 77.8 FSA K-Force Light, Vero Pro 104 30 73.5 Shimano XT, LX 4-arm outer 12 SPD, Sugino MX350. Some are threaded. See RaceFace compatibility table. 102 32 72.1 Shimano 2003 XTR MX960 4-arm middle, 96 30 67.9 Shimano compact triple cranksets models M782, M672, M622, M612 94 30 66.5 SRAM XO1, X1, GX, NX 90 30 63.6 FSA: K-Force Modular Supercompact, Omega Pro, Powerbox Supercompact Stealth, Road Modular, Vero Pro 88 28 62.2 Shimano M985 68 22 48.1 Shimano XTR M950, M952 4-arm inner, FSA Comet Modular 64 22 45.3 Shimano XTR M960, XT, LX 4-arm inner. See RaceFace compatibility table. 58 20 41.0 Sugino MX350 4-arm inner
4-Bolt Cranks/Chainwheels, uneven spacing:
Measurements between adjacent holes of uneven patterns are adjusted to nearest whole degree of angle between bolt holes, reflecting probable correct values. The first number given is for holes either side of the crank. If there are three spacings, the last and smallest is for holes opposite the crank. BCD (mm) Smallest Ring Between adjacent holes (mm) Application 110 34 90.1, 63.1 Shimano Dura Ace 9000, Ultegra 6800, 105 5800, Tiagra 4703, 4700; Dura Ace with modification 110 34 89.0, 64.7 SRAM Apex 1. 72/108 degree angles. Shimano is 70, 110. 110 34 84.3, 77.8, 70.7 FSA Gossamer ABS, K-Force ABS, Powerbox, SL-K ABS 100 32 92.7, 64.3, 58.8 3T Torno. Must use 3T bolts. Looks like a 5-bolt pattern with one bolt missing. 96 30 78.6, 55.1 Shimano XT M8000, SLX M7000, Deore M6000, 10mm holes; XTR M9000 and M9020, M7 threaded holes. 96 36 73.5, 67.9, 61.7 FSA 96/68 SLK MTB ABS 76 26 65.8, 48.9 FSA Afterburner, Comet, K-Korce, SLK MTB ABS 76 25 62.3, 53.7, 48.9 SRAM XX1 11-speed, Cannondale, Specialized Stout. Threaded for M8 bolts. 68 22 52.1, 48.1, 43.7 FSA Comet MTB Modular, Comet triple, K-Force Modular, SL-K MTB Modular, V-Drive MTB Modular 64 22 52.4, 36.7 Shimano XT, SLX, XTR 11-speed with the "X" shaped bolt pattern.
5-Bolt Cranks/Chainwheels: The BCD is: 1.701, 1/sin 36°, times the spacing between adjacent holes, 1.052 , 1/sin 72°, times the spacing between non-adjacent holes. BCD (mm) Smallest Ring Between adjacent holes (mm) Between non-adjacent holes (mm) Application 151 44 88.8 143.6 Very old Campagnolo standard (pre '67) (Obsolete) 144 41 84.6 137.0 Old Campagnolo standard, still used for track; S-A FCT 135 39 79.4 128.4 Current Campagnolo standard 130 38 76.4 123.6 Standard Road double and triple (outer 2); S-A FCS 128 38 75.2 121.7 Nervar Sport, Star (Obsolete) 122 38 71.7 116.0 Stronglight 93, 101, 103, 104, 105 (Obsolete) 118 36 69.4 112.2 Ofmega, SR (Obsolete) 116 35 68.2 110.3 Old Campagnolo Gran Sport touring, Victory, Triomphe 110, 112 34 64.7, 65.2 104.6, 105.6 Campagnolo CT inner/middle/outer with one bolt at larger diameter behind crank 110 38 84.3, 77.8, 70.7, 46.5 FSA K-Force ABS: uneven pattern, 4 bolt with extra bolt behind crank 110 33 64.7 104.6 Touring double, standard triple outer 102 32 60.0 97.0 Avocet triple inner (obsolete). Note, NOT same as Campagnolo. 100 31; 36 58.8 95.1 Merz adapter; Campagnolo triple inner (Obsolete) 94 29 55.3 89.4 Compact triple outer 93 28 58.5, 52.7, 55.3, 54.0, 52.7 Wolf Tooth "CAMO", barely noticeable uneven spacing, requires Wolf Tooth spider and bolts. Dimensions are reverse-engineered from photos, may be slightly wrong. 92 30 54.1 87.5 Shimano Dura-Ace triple inner 90 30 52.9 85.6 Edco, Mavic triple inner (old) 86 28 50.5 81.8 Stronglight 80, 99, 100, SR Apex (Obsolete). Chainwheels must be installed back to back, triple shifts poorly. 85 28 50.0 80.8 Old Shimano Deore, Takagi triple inner. (Obsolete) 80 26 47.0 76.1 Tevano (TA Campagnolo clone) triple inner. Bolts not interchangeable with others. 74 24 43.5 70.4 Standard ("full-sized") triple inner, used with 110 mm, 130 mm or 135 mm outer. 58 20 34.1 55.2 Compact granny 56 20 32.9 53.3 Sun Tour Compact granny (Obsolete) 50.4 n/a 29.6 47.9 TA Cyclotouriste, Criterium, Lambert, Shimano Deore, others: attachment for outer chainring; 7 mm holes. 6- and 3-Bolt Cranks/Chainwheels: The BCD is: 2.000, 1/sin 30°, times the spacing between adjacent holes (6-bolt), 1.154 , 1/sin 60°, times the spacing between adjacent holes (3-bolt) or non-adjacent holes (6 bolt) BCD (mm) Smallest Ring Between holes 60° apart (mm), 6-bolt Between holes 120° apart (mm) Application 157 78.5 136.0 Several very old Euro models 152 43 76 131.6 TA Criterium bolts between outer chainwheel and others. 143 42 71.5 123.8 Lambert. Inner ring threaded. 140 40 121.2 Campagnolo Gran Sport inner 116 36 100.4 TA Professional (10 mm holes), many old Euro steel cranks 116 36 58 100.4 TA Randonneur: bolts are between outer chainwheel and others. 112 ? 97.0 Takagi 106 32 91.8 Sugino Maxy, others w/8mm holes, SR Apex w/10mm holes. 95 30 82.3 Shimano 600, 310 88.9 (3.5") 30? 77.0 Nicklin, Cross, Williams (very old) 86 28 74.5 FSA Pro MTB 386, Comet 386 MTB 85 28 73.6 SR Custom 3 80 26 40 69.2 TA Cyclotouriste, Lambert: bolts between outer chainwheel and others. 70 24 60.6 René Herse. 10mm holes.
Quelle
Dieser Artikel basiert auf dem Artikel Sheldon Brown's Bicycle Crank/Chainring Bolt Circle Diameter Crib Sheet von der Website Sheldon Browns. Originalautor des Artikels ist Sheldon Brown mit Ergänzungen durch John Allen.