Rohloff Speedhub 135mm Rear hub

RULES FOR SPOKES, LACING, AND CROSS PATTERNS:
(summarized from the manual)
As of some time in early 2021, Rohloff REQUIRES their own spokes to be used to maintain the warranty. They have spokes manufactured by Sapim with a perfectly smooth underside of the spoke head to avoid creating stress risers, and a custom elbow bend length, again likely to control deformation of the hub flange and the creation of stress risers that can lead to eventual flange failure.

26" and larger wheels must always be laced 2x. 24" and smaller wheels must always be laced 1x.

Leading spokes should be heads-in; Trailing spokes heads-out.

Spokes must not cross directly over the hub cap fixing screws (on the left flange) on 24” or smaller wheels!

COGS:
The driver uses a proprietary 6-start m34x6 P6 thread standard. A proprietary 4-prong tool visually similar to a BMX freewheel remover is used to hold the hub driver stationary while a chainwhip loosens the cog. (the tool's prongs have an OD of 32.5mm, an ID of 28.2mm, and are arranged in symmetrical quadrants with a prong width of 5.92mm)

The hub comes stock with a 16t cog. 15t, 17t, and 21t cogs are available, and the 15/16/17t/21t threaded cogs are all reversible to wear the other side of the cog teeth. Rohloff makes a 15t threaded cog for applications with small wheel sizes, but it requires the teeth to be mounted off-center to clear the hub shell, and is thereby not reversible like the other cogs.

CHAINLINE:
15/16/17/21t threaded cogs = 54mm (symmetrical; can be flipped to double life)
13t threaded cog = 58mm (asymmetrical; cannot be flipped)
8540 splined carrier (snapring) = 57mm
8540s slim splined carrier (snapring) = 55mm (15t or larger cogs only)
8540L splined lockring carrier = 57mm

BELTLINE:
8540L splined lockring carrier = 57mm
8540sL slim splined lockring carrier = 53mm
(do not use belt cogs with 8540 or 8540s snapring-type carriers!)

SPLINED CARRIERS:
8540 = 13.5mm tall and works with all cogs; 8540s = 11.5mm tall and works with 15t and larger cogs. The splined carrier has largely superseded the threaded cog system. The carrier threads onto the same 6-start threads that the cog would thread onto. Cogs fit onto a proprietary 13-spline interface and are secured with a snapring with a 2.5mm round cross section, or a threaded lockring (L versions). Splined cogs are 2.0mm thick. Note that chainline with the various versions of the splined carriers are slightly different than the classic threaded cogs.

GATES BELT DRIVE INFO:
For Gates Carbon Drive belt compatibility, a special version of the splined carrier is required that utilizes a threaded lockring instead of a snapring (p/n 8540L). This clamps the belt cog tightly, preventing slight movement that could cause wear or noises. The aluminum lockring uses an 8-prong tool (p/n 8518) for installation and removal. The interface of the tool has a 51mm OD, 46.4mm ID, 4.75mm tooth width, and 3.5mm tooth height. Note that this is identical to the Bosch Gen2 chainring lockring tool EXCEPT the Bosch tool does not have sufficient interior clearance to fit over the Rohloff hub protruding parts. Park Tool LRT-1 appears compatible with the Bosch lockring AND has interior clearance that appears similar to the Rohloff tool based on photos (not tested).

The minimum allowed primary gear ratio is 1:2.35 to prevent potential damage to the internals from too much input torque. Here are the smallest permitted chainring sizes for each available cog:
13t cog = 31t or larger chainring
15t cog = 36t or larger chainring
16t cog = 38t or larger chainring
17t cog = 40t or larger chainring
21t cog = 50t or larger chainring
(For large riders or tandem applications, it would be wise to use a higher primary ratio)

7/26/2020 -- updated flange spacing to 58mm (29mm offset per side) to match published specs; it has been 60mm (30 per side) here for some time. Have not held a ruler to a hub to see if I agree with this and confirm that this measurement is to the midpoint of the flanges. -Karl