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Chainline on Fixed-gear and Singlespeed Bicycles
Translations of this article (older version): German German flag
Sheldon Brown photo
by Sheldon "Fixed Gear" Brown
revised by John "Infernal Gears" Allen
Spoke Divider

Chainline

Read this article in connection with the lead article on chainline, It covers chainline measurement, and adjustment of the front chainline (at the crankset). This article covers the adjustment of the rear chainline of a fixed sprocket or single-speed freewheel.

The word "chainline" refers to how straight the chain runs between the front and rear sprockets. Ideally, both sprockets should be in the same plane, so that there is no sideward motion or stress to the chain. This constitutes "perfect chainline". This article covers issues specific to bicycles without derailers.

Chainline Standards:

Application Dimension Notes
Track/Coaster Brake
Traditional One-Speed
Older internal gear hubs
40.5-42 mm Older bikes with 110 spacing would be on the smaller end of this range
Newer bikes with 120 mm spacing normally use 42 mm. Many newer internal-gear hubs have spacing of 135 mm, and a large chainline.
Singlespeed MTB 52 mm Wider chainline need for chainstay clearance on MTBs.

This is close to the chainline of the outer ring of a typical MTB triple

Rohloff Speedhub 54 mm
(58 mm w/13 tooth)
Singlespeed MTB
Alternate
47.5 mm White Industries ENO hubs use this chainline, which lines up with the middle position of a typical MTB triple.
It's also fairly close to the outer position of a typical "road" double.

Measurements

I have measured a selection of track sprockets, single freewheels and hubs with respect to chainline (units are millimeters.) The "Chainline" column is the distance from the mounting shoulder to the centerline of the sprocket teeth.

To figure the actual chainline for a given combination, add the number from the "chainline" column of the sprocket or freewheel to the corresponding "chainline" column of the hub chosen.

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Fixed (Track) Sprockets
Model/TypeNominal WidthChainline
(From Shoulder)
Measured widthTotal thicknessThread Thickness
Campagnolo3/32"7.02.08.07.8
Campagnolo1/8"6.53.08.07.2
E.A.I.3/32"7.132.28.238.05
E.A.I.1/8"6.733.028.248.05
Miche Quick Change Splined3/32"5.85/5.151.97.727.3
Miche Quick Change Splined1/8"5.85/5.153.07.727.3
Phil Wood3/32"5.862.37.017.01
Phil Wood1/8"6.053.027.567.06
Shimano Dura-Ace3/32"6.492.117.557.55
Shimano Dura-Ace1/8"7.053.058.587.7
Soma 3/32"6.371.867.37.3
Soma 1/8"6.93.008.46.9
Sugino Gigas1/8"7.03.08.57.5
Sun Tour Superbe3/32"6.222.267.357.35
Sun Tour Superbe1/8"6.933.058.467.5
Surly New (2005)3/326.42.07.47.4
Surly New (2005)1/8"5.937.47.4
Surly Old 3/325.282.056.316.31
Surly Old1/8"5.072.76.426.42
 
Single-Speed Freewheels
Model/TypeNominal WidthChainline
(From Shoulder)
Measured width
ACS3/32"7.962.16
Shimano3/32"7.892.08
Shimano1/8"8.673.0
Tristar1/8"7.712.96
White Industries3/32"8.732.17
 
Single-Speed and Fixed-Gear Hubs
Model/TypeTrack/MTBOLD SpacingAdjustable?*Chainline
Center to Shoulder
Left SideRight SideDrillings
Ambrosio large flangeTrack120?36FixedFixed32
Campagnolo small flange 2002Track120Yes36PlainFixed28, 32, 36
Campagnolo C-Record Large flangeTrack120Yes35.9PlainFixed28, 32, 36
Gold TecTrack120, 130, 135Yes39.5FixedFixed32, 36
I.R.O.Track120No36.0 Fixed/Free32
KogswellMTB135No45.3FixedFixed32
MicheTrack120Yes36.3PlainFixed28, 32, 36
On-One Full MontyMTB135No43.3PlainFree32, 36
Phil Wood TrackTrack120, 126, 130No36.75Plain
Fixed
Free
Fixed28, 32, 36
Phil Wood K.I.S.S. OffMTB135No45.35Plain/FreeFixed/Free32, 36
Shimano Dura-Ace 7700Track120Yes35.3 Fixed28, 32, 36
Shimano Dura-Ace 7700 Small FlangeTrack120Yes35.3 Fixed28, 32, 36
Shimano Dura-Ace 7600 Large FlangeTrack120Yes35.4 Fixed28, 32, 36
SovosTrack112Yes33.5FreeFixed36
SpotMTB135No47.25PlainFree28, 32, 36
SRAM
Singlespeed
Track/MTB 120, 130Yes See in IG Hub list Plain Fixed/Free
(Switchable)
32
Surly TrackTrack120Yes36.22FreeFixed32
Surly 1 x 1MTB135Yes46.5FreeFixed/FreeDrillings
Suzue BasicTrack117-120Yes34.74FreeFixed28, 32, 36
Suzue Promax (cartridge)Track120Yes35.0FreeFixed28, 32, 36
Suzue Promax NJSTrack120Yes35.0FixedFixed28, 32, 36
Von DesselMTB135No45.9FreeFixed32
White Industries ENOTrack/MTB126, 130, 135No39.1FreeFixed28, 32, 36

Spoke Divider

Chainline Adjustment, Sprocket Spacers and Dishing

Chainline may be adjusted at the rear wheel by rearranging spacers on the rear axle, and with a steel frame, also by re-spacing the rear dropouts to allow use of a longer or shorter rear axle. Adjustable hubs use conventional threaded axles, so you can increase the OLD spacing by removing the locknuts and adding spacer washers.

If you add equal thicknesses to both sides, the chainline is unaffected, since it's measured from the middle outward.

If you add more spacers to one side, or move them from one side to the other, you can change the chainline, but this will render a double-sided hub unusable on one side or the other, since you'll be increasing the chainline on one side while decreasing it on the other -- unless you also use a double chainring in front. Moving spacers from one side to the other also will disturb the alignment of a disc brake.

axel-set photo

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Thanks to John Dacey, Marten Gerritsen and Nilay Kothari for some of these data.

Spoke Divider

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