If the manufacturer you need is not in the list, create it as a
new manufacturer in the database
, then return here.

Model Name

What is this part called?
Don't include position or spacing or axle type info unless
it is part of the name used by the manufacturer.
For Shimano hubs, lead with the series name (if applicable)
and use the FH/HB prefix to the model number.
For example: "Ultegra HB-6600" or "Deore XT FH-M775"

Spoke Interface Type

Straight pull

If this is incorrect, back up and start
over from the appropriate submission form.

Spacing mm

QR hubs: use OLN spacing (not the overall axle length).
Thru-axle hubs: use endcap-to-endcap spacing.
Please enter the intended spacing even if the sample
measured is slightly off. (for example: a hub that
measures 134.82mm would be entered as 135mm)

Axle Type

This is the axle diameter that fits the dropouts.
(Common QR hubs are 9mm front and 10mm rear,
not the 5mm outside diameter of the skewer shaft.)
For thru-axle hubs, this is the outside diameter of
the thru-axle that fits the hub.

Brake Type
Drive Type

For hubs that can accept multiple freehub body
types, please choose the most common that makes
sense. Eventually I would like hubs to be able to have
multiple options selectable, but this is a ways off.
Note that Shimano 11spd MOUNTAIN (Dyna-Sys 11spd)
is the same thing as Shimano 8/9/10 (34.95mm).
Shimano 11spd ROAD is the wider 36.75mm freehub body.

Internal Gearing
Dynamo Type

Important note about the hub dimensions published on

Shimano publishes hub dimensions in a relatively confusing manner. If you are getting hub data from, these values need to be altered before being entered into FreeSpoke (or any other spoke calculator for that matter).

Shimano usually lists the actual physical outside diameter of the hub flanges as "Flange Diameter", which is the wording wheelbuilders frequently use to refer to the pitch circle diameter (PCD) of the spoke holes drilled in the hub flanges. Shimano lists the value we need as PCD, right next to the dangerously-named Flange Diameter values.

Shimano does not provide center-to-flange values. Instead, they provide the flange-to-flange spacing and the overall offset of the flanges as an assembly. Furthermore, their flange-to-flange spacing always seems to be the outside-to-outside spacing, rather than the center-to-center spacing wheelbuilders would be expecting.

The formula I use is [published flange-to-flange spacing] divided by two, plus or minus [overall offset], minus half of the [flange thickness at the spoke holes]. The larger number is typically the non-drive-side (or non-rotor-side) center-to-flange, and vice versa. I assume a flange thickness of 3mm to be plenty close enough for spoke calculation purposes (so we subtract 1.5mm from each side), but obviously I prefer to have actual data when possible.

Please note whether the values you are submitting were derived from Shimano's published data or from actual measurements of a hub specimen in the notes field. Thank you! -Karl

Live preview: hub dimension diagram

(uses javascript to update rendered hub shell as values are changed)

Left flange diameter (PCD) mm

The pitch circle diameter (PCD) of the drilled spoke
holes, NOT the outside diameter of the flange.

Right flange diameter (PCD) mm
Left flange offset (C-F) mm

Distance from the midpoint between the dropout
faces to the midpoint of the holes drilled through the
flanges. NOT to the inside or outside face of the flange.

Right flange offset (C-F) mm
Left spoke hole offset mm

Distance the spoke head sits past the symmetry line.
(Specific to straight-pull hubs!)

Right spoke hole offset mm
Weight (grams)

Ideally measured without a skewer or thru-axle.
Feel free to explain the weight scenario in the notes.


Optional link to product information
(please begin with http:// or https://)


Will appear on the detail page for this part

Email address

This allows me to contact you about
clarifications, etc.
(will not be published)

Credit contribution to

Your name or handle that will be visible on the part detail page as a credit.

Note to moderator

If there is any info you'd like me to see while I am reviewing
submissions, put it here! :-) (will not be published)