Product Code Database
The Rohloff Speedhub is an epicyclic internal hub gear for bicycles, developed and patented by Rohloff AG. It has been manufactured and marketed by that company since 1998. Die weltbeste Fahrradnabe kommt aus Hessen, article in Financial Times Deutschland from 2009-04-16, retrieved 2010-08-31 The Speedhub 500/14 has 14 equally spaced, sequential, non-overlapping operated by a single twistgrip. The overall gear range is 526%, meaning the highest gear is 5.26 times as high as the lowest gear. Individual gear shifts when shifting up give an increase of about 13.6% (equivalent to a decrease of about 12.0% when shifting down).
The Speedhub is more expensive than competing bicycle gear systems (both hub gears and ), and it is more than 450 grams heavier than a comparable set of derailleur gears, but offers about the same gear range (and at its ratio of 5.26:1 more range than a typical road bike ratio of 4.28:1 with 50/34 Crankset and 11 to 32 tooth cassette) while requiring significantly less maintenance and having a longer service life. It is therefore mainly used in expensive and in , where its lack of (vulnerable) external components is useful.
Either of the above comes with the following three options:
There also two types of axle available:
, the Speedhub is available in three colours: silver, red or black.
Finally, the Speedhub is available with either 32 or 36 spoke holes.
The above options are combined so a particular unit could be a Speedhub "CC DB OEM2 silver, 32 spoke holes" or a Speedhub "TS EX OEM black, 36 spoke holes" for example.
All planet gears of the first 2 planetary systems are on the same carrier (4 gears on each axle, with each set of 2 locked to the same shaft, i.e. 2 shafts rotating on a common axle). The common planet carrier is the means to transfer power between planetary system one and two. Input is applied to the first ring gear. Either sun gear 1 or 2 must be locked to serve as reactionary member (but never both). With the planet carrier the output of the first system, the result is speed reduction. With the planet carrier the input of the second system and its ring gear (ring gear 2 of the mechanism) the output, the result is speed increase. Because a system consists of two suns of different size, two ratios each for reduction and increase are selectable. The second ring gear of the mechanism is directly bolted to the final sun gear of the reduction stage. When the final stage's ring gear is held stationary, the result is speed reduction at the planet carrier output. With planet carrier and ring gear of the final reduction stage locked (and the final ring gear free to spin), it gives direct drive and a reduction ratio of 1:1.
Clutch #2 cannot be engaged. It is simply an overrun clutch that will be locked and transmit power when suns #3 and #4 are disengaged from the center axle and will overrun when one of the sun gears is locked and power is transmitted to the ring gear by the planets. In other words, ring gear 2 can either rotate at the same speed as the shared planet carrier or at a higher speed.
Clutch #3 couples the reduction stage sun gear to its ring carrier (direct drive), clutch #4 locks the reduction stage ring gear to the stationary axle. Freewheeling is achieved by allowing ring gear 3 to freewheel in a forward direction. It will thus either freewheel relative to the axle when final reduction is enabled, or to the sun gear when final reduction is in direct drive. In other words, when the final reduction stage is in direct drive, the freewheeling contribution will put the planetary system into reverse overdrive with the planet carrier now the input and the ring gear the output that has no load.
The IGR (inner gear ratio), hub revolutions per sprocket revolution of the Speedhub, lies between 0.279 and 1.467 depending on the gear chosen. Gear 11 has a ratio of 1.0. The Speedhub has a 526% range between the highest and lowest gear. The range of gears in detail is:
| 1 | 0.279 | stationary | 0.682 | engaged | 1 | ||||
| 2 | 0.316 | stationary | 0.774 | engaged | 1 | ||||
| 3 | 0.360 | stationary | 0.682 | stationary | 1.292 | ||||
| 4 | 0.409 | engaged | 1 | engaged | 1 | ||||
| 5 | 0.464 | stationary | 0.774 | stationary | 1.467 | ||||
| 6 | 0.528 | engaged | 1 | stationary | 1.292 | ||||
| 7 | 0.600 | engaged | 1 | stationary | 1.467 | ||||
| 8 | 0.682 | ||||||||
| 9 | 0.774 | ||||||||
| 10 | 0.881 | ||||||||
| 11 | 1.000 | ||||||||
| 12 | 1.135 | ||||||||
| 13 | 1.292 | ||||||||
| 14 | 1.467 |
As with all hub gears, there is a torque reaction that must be countered if the internals are not to rotate, and this is routed to the bicycle's frame by means of specially designed wheel dropout slots (OEM versions), or a torque bar bolted to the frame (EX) or the disc brake mount (DB).
The hub contains 25 ml of oil which should be replaced once a year or after 5,000 km (manufacturer advice). Overfilling can lead to leaks, as can laying the hub/cycle on its side in some low-pressure aircraft holds.
The sprocket on the hub is made for standard-pitch derailleur-type bicycle chains (ISO 082) and is offered with different numbers of teeth, like 13/15/16/17. The 15-, 16-, and 17-tooth sprockets are reversible, offering double sprocket life once the sprocket is worn out in one direction. The 13-tooth sprocket is non-reversible and has a 4 mm outward offset, changing the chain-line from 54 to 58 mm, this because the smaller sprocket makes the chain run closer to the axle, and the chain would rub the hub shell if the sprocket were not offset.
| 32 or 36 |
| M34 x 6 P6 |
| ( with 13-tooth sprocket) |
| 21° |
| above €900 |
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