Gears and gear ratios of the Rohloff SPEEDHUB
This page is for those who want to know how the Rohloff SPEEDHUB 500/14 works inside, and what to keep in mind before changing the gearing of your bike.
Range and gear steps
Section titled “Range and gear steps”| Feature | Value |
|---|---|
| Number of gears | 14 |
| Gear steps | even, 13.6 % |
| Total range | 526 % |
| Maximum input torque at the hub | 130 Nm |
| Oil fill | 25 ml max. |
The total range, the ratio between the lowest and the highest gear, decides which gradients you can climb and which top speed you can reach. The gear step, the difference between two neighbouring gears, decides how smoothly you keep your rhythm when you shift. With a range above 500 % and even steps below 15 %, every rider can always find the right gear at the right moment and ride at a comfortable cadence. The SPEEDHUB’s range is about that of a 2×10 derailleur system, and you can shift through all the gears in one twist, even at a standstill.
How the 14 gears are made
Section titled “How the 14 gears are made”Inside the hub are three planetary gear sets connected in series. A planetary gear set consists of a central sun gear, an outer ring gear and several planet gears that roll between them, like planets around a sun. Because the load is shared between several planet gears, high torque can be transmitted in a compact space.
- Gear sets 1 and 2 are identical but mounted as mirror images on a shared planet carrier. Each has two sun gears that can be locked to the axle, or the set can run 1:1, which gives three ratios per set. Together they produce seven gears.
- Gear set 3 works as a reduction stage (0.409). Switching it in or out doubles the seven gears to 14.
The drive enters through the sprocket into gear set 1, and leaves through the planet carrier of gear set 3, which is coupled to the hub shell. The first turn of the shift shaft inside the axle shifts gears 1 to 7. At the change from 7 to 8, gear set 3 switches to direct drive, and the second turn shifts gears 8 to 14.
The ratio of every gear
Section titled “The ratio of every gear”The table shows how many times the hub turns for one turn of the rear sprocket, and how the three gear sets combine to produce it.
| Gear | Set 1 | Set 2 | Set 3 | Hub turns per sprocket turn |
|---|---|---|---|---|
| 1 | 0.682 | 1 | 0.409 | 0.279 |
| 2 | 0.774 | 1 | 0.409 | 0.316 |
| 3 | 0.682 | 1.292 | 0.409 | 0.360 |
| 4 | 1 | 1 | 0.409 | 0.409 |
| 5 | 0.774 | 1.467 | 0.409 | 0.464 |
| 6 | 1 | 1.292 | 0.409 | 0.528 |
| 7 | 1 | 1.467 | 0.409 | 0.600 |
| 8 | 0.682 | 1 | 1 | 0.682 |
| 9 | 0.774 | 1 | 1 | 0.774 |
| 10 | 0.682 | 1.292 | 1 | 0.881 |
| 11 | 1 | 1 | 1 | 1.000 |
| 12 | 0.774 | 1.467 | 1 | 1.135 |
| 13 | 1 | 1.292 | 1 | 1.292 |
| 14 | 1 | 1.467 | 1 | 1.467 |
Gear 11 is the direct gear (1:1): all three sets pass the drive straight through.
Minimum ratio when changing sprockets
Section titled “Minimum ratio when changing sprockets”The ratio between the front and the rear sprocket (front teeth divided by rear teeth) shifts the whole range of the hub up or down. Rohloff permits the following as the smallest ratios:
| Drive | Riders up to 100 kg (ratio about 1.9) | Riders over 100 kg and tandems (ratio about 2.5) |
|---|---|---|
| Gates belt | 39/19, 39/20, 42/22, 46/24 | 46/19, 50/20, 55/22, 60/24 |
| Chain | 40/21, 36/19, 34/18, 32/17, 30/16, 28/15 | 53/21, 48/19, 45/18, 42/17, 40/16, 38/15 |
Rohloff’s recommendation: for everyday riding, a ratio of 2.5–2.8 has proven sensible. Solo riders heading off-road and into the mountains can go down to the minimum of 1.9.
Weight and efficiency
Section titled “Weight and efficiency”A complete Rohloff SPEEDHUB 500/14 with shifter, shift cables and cable stop weighs about 1820 g. The derailleur parts it replaces (rear and front derailleur, two shifters, rear hub with cassette, small and middle chainrings) weigh around 1600 g, depending on the groupset.
The efficiency is comparable to a high-quality derailleur system: depending on the gear, the losses of the drivetrain are between 1 % and 5 %, so the efficiency is between 95 % and 99 %.
Can I fit different sprockets to get easier gears?
Only within Rohloff’s minimum ratio: front teeth divided by rear teeth must not fall below about 1.9, or about 2.5 for riders over 100 kg and tandems. On a belt drive, 39/20 or 42/22 are examples of the smallest permitted pairs. A change also affects belt length and tension, so please ask us first.
What is the gear range of the Rohloff SPEEDHUB?
526 % across 14 evenly spaced gears, with a step of 13.6 % between neighbouring gears. That is about the range of a 2×10 derailleur system, and you can shift through all the gears in one twist, even at a standstill.