As of 2018, fatbikes and disc brakes have led to a several new standards. The problem of disc brakes' pulling the hub out of the front dropouts (see James Annan's article) has been addressed with thru axles, which insert into a fork with a hole rather than a slot at the end of each blade. Also see our article on thru axles, and our article about disc brakes for information on disc-brake issues.
| Front | |
|---|---|
| 70 mm | Birdy, Breezer Itzy front hub. |
| 74 mm | Brompton front hub, 8 mm axle; Schimidt SON XS Bro generator hub. |
| Bike Friday tikit, Dahon Speed, Moulton front hub, 9 mm axle; Schmidt SON XS DaTi generator hub | |
| 79 mm | Dahon Vitesse front hub (report from reader, unconfirmed). |
| 91 mm | Low-end front hubs; Nottinghum Raleighs. |
| 96 mm | Older front hubs, especially French. |
| 100 mm | Modern front hubs with 12 and some with 15mm thru axle |
| 110 mm | "Boost" front hubs with 12, 15, or 20 mm thru axles. |
| 120 mm | Some front "Boost" |
| 135 mm | Front fatbike with quick release. Some are offset, and some front and rear wheels are interchangeable. |
| 142 mm | Front fatbike with rigid thru-axle fork,15mm axle |
| 150 mm | Some fatbike front hubs with 15mm thru axle |
| Rear | |
| 110 mm | Rear older track, coaster brake and other single-speed hubs. |
| 114 mm | Rear 3-4-speed, many internal-gear hubs. This is US, U.K. Same as 4 1/2 inches. |
| 120 mm | Rear 5-speed, Ultra 6, newer track hubs. |
| 126 mm | Rear 6- and 7-speed (road). |
| 130 mm | Rear 7-speed (MTB) and 8- 9-10-11-speed (road) except disc brake |
| 135 mm | Rear 7- 8- 9-10-11-speed (MTB); rear with disc brake (road). Some MTB with 12mm thru axle |
| 135 mm offset |
Original Surly fatbike, offset 17.5 mm to right |
| 140 mm | Rear tandem. |
| 142 mm | Rear with 12mm QR, 12mm or 15mm thru axle |
| 145 mm | Rear tandem (newer models.) |
| 148 mm | Rear "Boost", MTB with 12mm thru axle |
| 150 mm | Retro-Choppers, some Downhill and Freeride models. |
| 157 mm | SRAM rear DH |
| 160 mm | Rear tandem (new Santana proposed standard.) |
| 170 mm | Rear symmetric fatbike with quick release for 4" tire |
| 177 mm | Rear symmetric fatbike with thru axle for 4" tire, 12mm axle |
| 190 mm | Rear symmetric fatbike with quick release for 5" tire, 12mm axle with QR |
| 197 mm | Rear symmetric fatbike with thru axle for 5" tire, 12mm thru axle |
Overall axle length for quick-release hubs is commonly 11 mm longer than the overlocknut distance listed, 5.5 mm on each side. Most hubs with nutted axles can easily be modified for larger spacing by adding washers, within limits. For overlocknut distance of specific makes and models of internal-gear and singlespeed hubs, see the articles on chainline.
Sprocket spacing given is for inner sprockets. Spacing of outer sprockets may be slightly greater to prevent the chain from rubbing against the next larger sprocket. Overall width of freewheels and cassettes may therefore slightly exceed the dimensions given. Some SunTour freewheels used oddly mixed spacings -- see linked photos.
| Brand and model | Center-to-center Spacing |
Sprocket Thickness | Spacer Thickness | Total Width |
|---|---|---|---|---|
| 5-speed | ||||
| "Regular" 5-speed |
5.5 mm | 2.0 mm | 3.5 mm | 24.0 mm |
| G. Caimi/Everest/Simplex 5-speed |
5.35 mm | 1.85 mm | 3.5 mm | 23.2 mm |
| 6-speed | ||||
| "Regular" 6-speed |
5.5 mm | 2.0 mm | 3.5 mm | 29.5 mm |
| G. Caimi/Everest/Simplex 6-speed |
5.35 mm | 1.85 mm | 3.5 mm | 28.6 mm |
| Sun Tour "Ultra" Freewheel 6-speed |
5.0 mm | 1.85 mm | 3.15 mm | 26.9 mm |
| Sun Tour Accushift XCD-6 6-speed |
5.5 mm | 2.0 mm | 3.5 mm | 29.5 mm |
| 7-speed | ||||
| Shimano HG 7-speed |
5.0 mm | 1.85 mm | 3.15 mm | 31.9 mm |
| Shimano IG 7-speed |
5.0 mm | 2.35 mm | 2.65 mm | 32.4 mm |
| Sachs 7-speed |
5.0 mm | 1.8 mm | 3.2 mm | 31.8 mm |
| SRAM Freewheel 7-speed |
5.0 mm | 1.8 mm | 3.2 mm | 32.8 mm |
| Sun Tour "Ultra" Freewheel 7-speed |
5.0 mm | 1.85 mm | 3.15 mm | 32.4 mm |
| Sun Tour MicroDrive 7-speed |
4.8/5.0 mm | 2.0 mm | 3 x 2.8 mm(L) 3 x 3.0 mm(H) |
31.5 mm |
| 8-speed | ||||
| Campagnolo 8-speed |
5.0 mm | 1.9 mm | 3.1 mm | 36.9 mm |
| Mavic 8-spd w/rounded dogs |
5.2 mm | 2.0 mm | 3.2 mm | 37.0 mm |
| Shimano 8-speed |
4.8 mm | 1.8 mm | 3.0 mm | 35.4 mm |
| Sachs 1997 8-speed |
5.0 mm | 1.8 mm | 3.2 mm | 36.8 mm |
| Sachs 1998+ 8-speed |
4.8 mm | 1.8 mm | 3.0 mm | 35.4 mm |
| SRAM Cassette 8-speed |
4.8 mm | 1.8 mm | 3.0 mm | 35.4 mm |
| SRAM Freewheel 8-speed |
5.0 mm | 1.8 mm | 3.2 mm | 36.8 mm |
| Sun Tour MicroDrive 8-speed |
4.8/5.0 mm | 2.0 mm | 3 x 2.8 mm(L) 4 x 3.0 mm(H) |
36.5 mm |
| 9-speed | ||||
| Campagnolo 9-speed |
4.55 mm | 1.75 mm | 2.8 mm | 38.2 mm |
| Shimano 9-speed |
4.34 mm | 1.78 mm | 2.56 mm | 36.5 mm |
| SRAM 9-speed |
4.34 mm | 1.8 mm | 2.54 mm | 36.5 mm |
| 10-speed | ||||
| Campagnolo 10-speed |
Variable (note) | 1.7 mm | Variable (note) | 38.8 mm |
| Shimano 10-speed |
3.95 mm | 1.6 mm | 2.35 mm | 37.2 mm (note) |
| Campagnolo 11-speed |
Variable (note) | 1.6 mm | Variable (note) | 40.1 mm (note) |
The total width given is that of the sprocket cluster --which may also be slightly wider due to wider spacign of the smaller sprockets.. A freewheel with splined sprockets has a flange behind the innermsot sprocket. The inner body of the freewheel may not be recessed so as to compensate completely for this flange depth, and so the total width the of the freewheel may be greater, affecting chainline and clearance at the right rear dropout. Sun Tour freewheels typically have a 2 mm flange and a 1 mm recess.
The innermost sprocket of Shimano 10-speed and Campagnolo 11-speed cassettes is inboard of the flange of the freehub body to move the sprockets to the left and make more room between the outermost sprocket and the dropout. The rear derailer may interfere with the spokes, especially if the innermost sprocket is relatively small or the wheel has an unusual spoke pattern.
Sprocket spacing varies across Campagnolo 10- and 11-speed cassettes to improve shifting in the midrange. 11-speed spacing also varies over the top 3 sprockets according to the actual ratios for better shifting with the most recent 11-speed rear derailleur. Thanks to Graeme at Velotech Cycling Ltd. (UK) for this information.
Last Updated: by Harriet Fell
