Gear transmission ratios

After testing the Gudereit LC-R and the Rohloff Speedhub across the Black Forest, I know I need some more power for steep inclines. A friend of mine politely checked the gear ratios of his bikes, both with 27 gear derailleurs, a trekking bike and a mountain bike.

The minimum and maximum transmission ratios of the Rohloff Speedhub are 0.279 (1st gear) and 1.467 (14th gear). The chainring of the LC-R counts 44, the pinion 17 teeth, resulting in a ratio of 2.6. This ratio multiplied with the ratio of the chosen gear results in the total ratio.

According to some web resources, the Rohloff also can be used with alternative chainring/pinion ratios like 42/17 (2.47), 32/13 (2.462), 36/15 (2.4) and 38/16 (2.375). The following table lists the ratios of both of my friend’s bikes, the current and the possible LC-R ratios:

Minimum Ratio
(1st gear)
Maximum Ratio
(14th gear)
Gear Range
Mountain Bike 0.65 4 615%
Trekking Bike 0.68 4 588%
Gudereit LC-R 44/17 0.72 3.79 526%
Gudereit LC-R 42/17 0.69 3.6 526%
Gudereit LC-R 32/13 0.69 3.61 526%
Gudereit LC-R 36/15 0.67 3.52 526%
Gudereit LC-R 38/16 0.66 3.48 526%

The current ratio is not bad per se. Instead it IMO is the optimal solution for the bike’s main purpose – travelling. But as I’m abusing it as a leisure bike in hilly regions, I’ll probably replace the 44 teeth chainring by a 42 teeth chainring, which seems to be a good compromise between power and speed.

For alternative hubs which are neither derailleurs nor Rohloffs, see Pinion and Hettlage (also see the german tongue technology review article at heise online).

3 thoughts on “Gear transmission ratios

  1. Sven Geggus

    Before I ordered my Rohloff based bike some 5 years ago I just calculated a gear ratio in the same range that I used before on my old 27 gear bike. See Speedhub manual page 22.

    This led to a tooth combination of 44/16. I still consider this to be the perfect fit for a general purpose 28″ bike.

    Looks like I now know why you called yourself slowrider on OSM :)

    You should probably have bought a 26″ bike instead! I really tend to think that your mountain rides are somewhat of an abuse for a general purpose trecking bike like the LC-R anyway.

    So just be carefull when you really do this: You will need another Version of the chainglider when changing the front gear.

  2. Pingback: Black Forest up- and downhill mapping « Points of Interest

  3. ce Post author

    Of course the purpose of the bike is not mountain biking. The current trips are mainly test trips to prove whether this bike can climb mountains :) .

    BTW: I removed the chain glider for the last two trips anyway. I understand that it is there to protect the chain from environmental influences. But it produces some noise which I dislike.

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