Rohloff Gearing

When I had my Rohloff bike built, I was not initially sure what gearing to go with. In the rear I chose the 16-tooth sprocket, as that seemed pretty standard. On the front I decided to start with a 42-tooth chainring. With my 170mm cranks and 26x1.9” wheels, that gave me a range of 18.9 to 99.2 gear inches, or a gain ratio of 1.4 to 7.4.

On my derailleur bike, the setup that I’ve been running since 2018 gives me a range of 21.9 to 117.8 gear inches, or a gain ratio of 1.6 to 8.8. I had done plenty of touring on that and felt pretty good about it. So something similar, but a hair lower, seemed like a good place to start with the Rohloff build.

Since then I’ve done a couple big tours with the Rohloff, and plenty of smaller escapades. I sometimes found myself getting down to the low gears more than I thought I ought to, which made me think that I probably should slap on a smaller chainring. Last month I finally got around to doing so.

36 and 38 tooth chainrings both seem to be common for Rohloff touring builds with 16-tooth sprockets. I had one of Rivendell’s Silver 38-tooth chainrings in my spare parts bin, so that’s what I went with. (If I was buying a new chainring I would probably try out the Surly Stainless Chainring.) This gives me a range of 17.1 to 89.7 gear inches, or a gain ratio of 1.3 to 6.7 – dropping my low-end about 1” lower. While I have yet to do any loaded touring with it, I’ve been enjoying the new gearing while tooling around town and ripping up the local dirt on weekends. There is some significant mountain touring in my near-future that will let me give this a proper trial, but so far I think this was the right call.

Swapping chainrings was super easy thanks to the Bushnell Eccentric Bottom Bracket. I’m still using the same Wippermann Connex 808 chain.

Over in Jolly Old England, the Thorn people advocate for 19-tooth sprockets. They argue that the larger diameter means that the chain doesn’t have to make such a tight bend, which makes for less opportunity for dirt to get inside the plates, thus leading to longer chain life, which in turn leads to longer sprocket life. That makes sense to me, and someday when my 16-tooth sprocket needs replacing I may try a 19-tooth. In that case I’d probably put the 42-tooth chainring back on, which would keep me in the same gearing neighborhood as what I currently have with the 38x16.