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Sheldon Brown's Bicycle Crank/Chainring Bolt Circle Diameter Crib Sheet

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The table below gives bolt-circle diameters for major brands. Aftermarket and less prominent brands tend to use the same bolt-circle diameters, for the sake of compatiblity.

With an even number of holes, a protruding part may make a direct measurement possible only with a caliper. With an.odd number of holes, none is directly opposite another, so the table gives mesaurements getwen holes, Measuring between non-adjacent holes increases precision, reducing the likelihood of mistakes.

Many references describe BCD measurements as "center to center," but there is nothing to measure at the center of a hole! Very fortunately, all of the bolt holes are the same size, and measuring from right side to right side or left side to left side avoids this problem!

Most 4-bolt and 5-bolt chainwheels have 10mm bolt holes, though some have 8mm or are threaded.. Most 3 and 6-bolt chainwheels have 7-9mm bolt holes. Other variations which affect compatibility::

After measuring BCD, you might check Wolf Tooth's Road and MTB chainwheel entries for details on newer 4- and 5-bolt chainwheels.

Many thanks to Ulrik Dobashi Hansen updates to the 4-bolt crank list.

4 Bolt Cranks/Chainwheels:

Beware of near-matches! Measure!
The BCD for evenly spaced patterns 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 2x10 and XX. Threaded.
112 34 79.2 Shimano XTR M950, M952 4-arm middle/outer, Campagnolo inner.
110 uneven 34 63.6/90.6 Shimano Dura Ace 9000, Ultegra 6800, 105 5800, Tiagra 4703, 4700; Dura Ace with modification
110 uneven 34 64.8/89.3 SRAM Apex 1
104 30 73.5 Shimano XT, LX 4-arm outer 12 SPD, Sugino MX350. Threaded. See RaceFace compatibility table.
102 32 72.1 Shimano 2003 XTR MX960 4-arm middle,
100 uneven 32 ? 3T Torno. Must use 3T bolts.
96 30 67.9 Shimano compact triple cranksets models M782, M672, M622, M612
96 uneven 30 55.2/78.8 Shimano XT M8000, SLX M7000, Deore M6000, 10mm holes
96 uneven 30 55.2/78.8 Shimano XTR M9000 and M9020, M7 threaded holes.
94 30 66.5 SRAM XO1, X1, GX, NX
88 28 62.2 Shimano M985
76 uneven 25 49.0/62.4/53.9 SRAM XX1 11-speed, Cannondale, Spcialized Stout - symmetric only around axis of crank. Threaded for M8 bolts.
68 22 48.1 Shimano XTR M950, M952 4-arm inner
64 22 45.3 Shimano XTR M960, XT, LX 4-arm inner. See RaceFace compatibility table.
64 uneven 22 ?/? Shimano XT, SLX, XTR with the "X" shape bolt pattern.
58 20 41.0 Sugino MX350 4-arm inner
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 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 58.7 95.1 Merz adapter; Campagnolo triple inner (Obsolete)
94 29 55.4 89.4 Compact triple outer
92 30 53.3 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)
Between holes
120° apart (mm)
Application
157   78.5 136.0 Several very old Euro models
152 43 76 131.6 TA Criterium: bolt circle is between outer chainwheel and others.
143 42 71.5 123.8 Lambert. Inner ring threaded.
140 40   121.2 Campagnolo Grand Sport inner
116 36   100.4 TA Professional (10 mm holes), many old Euro steel cranks
116 36 58 100.4 TA Randonneur: bolt circle is 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     77.0 Nicklin, Cross, Williams
85 28   73.6 SR Custom 3
80 26 40 69.2 TA Cyclotouriste, Lambert: bolts are between outer chainwheel and others.
70 24   60.6 René Herse. 10mm holes.

More cribsheets: Click here!

This page is intended as a quick reference primarily for the benefit of folks in the bicycle business. Feel free to print it out, but please don't reproduce it without proper credit and linkage.

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