Chainline on Bicycles without Derailers

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by Sheldon "Fixed Gear" Brown

revised by John "Infernal Gears" Allen

Original article: https://www.sheldonbrown.com/chainline-single.html on sheldonbrown.com

• Reproduced with the permission of John Allen and Harriet Fell — all rights reserved. The version on sheldonbrown.com is authoritative.
• Mirrored: 2026-10-05 · Last update of the original: see original

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.

Fixed (Track) Sprockets
Model/Type	Nominal Width	Chainline (From Shoulder)	Measured width	Total thickness	Thread Thickness
Campagnolo	3/32"	7.0	2.0	8.0	7.8
Campagnolo	1/8"	6.5	3.0	8.0	7.2
E.A.I.	3/32"	7.13	2.2	8.23	8.05
E.A.I.	1/8"	6.73	3.02	8.24	8.05
Miche Quick Change Splined	3/32"	5.85/5.15	1.9	7.72	7.3
Miche Quick Change Splined	1/8"	5.85/5.15	3.0	7.72	7.3
Phil Wood	3/32"	5.86	2.3	7.01	7.01
Phil Wood	1/8"	6.05	3.02	7.56	7.06
Shimano Dura-Ace	3/32"	6.49	2.11	7.55	7.55
Shimano Dura-Ace	1/8"	7.05	3.05	8.58	7.7
Soma	3/32"	6.37	1.86	7.3	7.3
Soma	1/8"	6.9	3.00	8.4	6.9
Sugino Gigas	1/8"	7.0	3.0	8.5	7.5
Sun Tour Superbe	3/32"	6.22	2.26	7.35	7.35
Sun Tour Superbe	1/8"	6.93	3.05	8.46	7.5
Surly New (2005)	3/32	6.4	2.0	7.4	7.4
Surly New (2005)	1/8"	5.9	3	7.4	7.4
Surly Old	3/32	5.28	2.05	6.31	6.31
Surly Old	1/8"	5.07	2.7	6.42	6.42

 

Single-Speed Freewheels
Model/Type	Nominal Width	Chainline (From Shoulder)	Measured width
ACS	3/32"	7.96	2.16
Shimano	3/32"	7.89	2.08
Shimano	1/8"	8.67	3.0
Tristar	1/8"	7.71	2.96
White Industries	3/32"	8.73	2.17

 

Single-Speed and Fixed-Gear Hubs
Model/Type	Track/MTB	OLD Spacing	Adjustable?*	Chainline Center to Shoulder	Left Side	Right Side	Drillings
Ambrosio large flange	Track	120	?	36	Fixed	Fixed	32
Campagnolo small flange 2002	Track	120	Yes	36	Plain	Fixed	28, 32, 36
Campagnolo C-Record Large flange	Track	120	Yes	35.9	Plain	Fixed	28, 32, 36
Gold Tec	Track	120, 130, 135	Yes	39.5	Fixed	Fixed	32, 36
I.R.O.	Track	120	No	36.0		Fixed/Free	32
Kogswell	MTB	135	No	45.3	Fixed	Fixed	32
Miche	Track	120	Yes	36.3	Plain	Fixed	28, 32, 36
On-One Full Monty	MTB	135	No	43.3	Plain	Free	32, 36
Phil Wood Track	Track	120, 126, 130	No	36.75	Plain Fixed Free	Fixed	28, 32, 36
Phil Wood K.I.S.S. Off	MTB	135	No	45.35	Plain/Free	Fixed/Free	32, 36
Shimano Dura-Ace 7700	Track	120	Yes	35.3		Fixed	28, 32, 36
Shimano Dura-Ace 7700 Small Flange	Track	120	Yes	35.3		Fixed	28, 32, 36
Shimano Dura-Ace 7600 Large Flange	Track	120	Yes	35.4		Fixed	28, 32, 36
Sovos	Track	112	Yes	33.5	Free	Fixed	36
Spot	MTB	135	No	47.25	Plain	Free	28, 32, 36
SRAM Singlespeed	Track/MTB	120, 130	Yes	See in IG Hub list	Plain	Fixed/Free (Switchable)	32
Surly Track	Track	120	Yes	36.22	Free	Fixed	32
Surly 1 x 1	MTB	135	Yes	46.5	Free	Fixed/Free	Drillings
Suzue Basic	Track	117-120	Yes	34.74	Free	Fixed	28, 32, 36
Suzue Promax (cartridge)	Track	120	Yes	35.0	Free	Fixed	28, 32, 36
Suzue Promax NJS	Track	120	Yes	35.0	Fixed	Fixed	28, 32, 36
Von Dessel	MTB	135	No	45.9	Free	Fixed	32
White Industries ENO	Track/MTB	126, 130, 135	No	39.1	Free	Fixed	28, 32, 36

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.

• Axle Re-Spacing/Re-Dishing
  This is the usual way to go for converting bikes from a multi-speed derailer setup to a single-speed fixed-gear or freewheel drive. The spacers are located just behind the outer locknuts, between the locknuts and the cones (or the bearing mounting nuts, if your hub uses cartridge bearings.) You will need cone wrenches and a general understanding of hub bearing adjustment to do this job.
  
  Assuming the rear hub's spacing already matches your frame's spacing, you can take spacer washers from one side of the hub and move them to the other side, thus shifting the entire hub from side to side. In the case of a hub originally meant for a multi-speed freewheel, there is usually a rather thick spacer on the right (freewheel) side of the hub. You can replace this with a stack of thinner spacer washers that add up to the same overall thickness, then distribute the washers from side to side as needed to get the chainline where you need it to be.
  
  Once you have done this, you'll need to re-dish the wheel by adjusting the spokes. This is a bit of trouble, but, in the case of multi-to-single-speed conversion, the re-dishing actually results in making the wheel much stronger than it was.
  
  Also see my article about frame spacing.
• Sprocket Dishing
  Most internal-gear hubs have "dished" sprockets that can be installed either dished in, or out, providing a choice of two different chainlines. Fixed-gear sprockets are usually intended to be installed with the flange facing inward, so the teeth are outboard. However, in many cases, it is possible to flip a fixed-gear sprocket over if you need to move the rear chainline to the left.
• Spacing Washers
  Sturmey-Archer internal-gear hubs generally have two 1/16" (1.6 mm) spacer washers next to the sprocket. These can be arranged in various ways, along with the dishing of the sprocket, to optimize chainline. Shimano makes the same diameter of washers in 1 mm thickness, for use with a 10-speed cassette. These are metal washers. Plastic washers that fit between the sprockets on a Shimano cassette have internal lugs that get in the way, and they compress too easily to be suitable for use with a threaded sprocket.

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

Copyright © 1998, 2008 Sheldon Brown

Original: https://www.sheldonbrown.com/chainline-single.html · Reproduced on en.wikipedalia.com with permission, all rights reserved.