However, the expense and hassle of changing gear ratios with the belt is considerable as a new belt is needed.
A friend-of-a-friend had just this problem with a Rohloff-mit-carbon-belt on a new bike on a cross-Canada ride this past summer. Starting in Vancouver, she realized in the mountains that her gearing was too high. They made it to Jasper, and eventually got a new belt and switched to a smaller chainring. That all took time (several days) and money, but once done, the rest of the ride was OK.
That happened in 2017 with a couple of other friends, one with a Rohloff-mit-chain. They had to switch from a 44T ring to a 36, also in Jasper (if you're going to have this problem, that's a good place to have it), but that change took just an hour.
It can take a while to find the right gearing -- on my Raven, I changed from a 17 x 38 to a 17 x 36, but only after a season and a half, including a 1500 km tour that included some hilly Swedish sections. I changed the front chainring on the Raven in 15 minutes; the more fiddly part of the changeover was getting the length right on the new, smaller chain.
When I built up my Nomad, I decided before I even had the frame in my possession that I wanted to have two sets of gearing, one for around home with an unladen bike and one for touring.
The unladen bike around home, from my other bikes I knew what gears I liked to use down a couple of long shallow downhill runs for my highest gear. And from a couple of nearby hills what I wanted as my lowest gear. With that knowledge, I calculated what chainring I needed, which was a 44T to come pretty close to replicating the gears I wanted. My stock Rohloff came with a 16T sprocket, not the more common 17T on most Thorns. Occasionally I have thought about trying a 42T, but it is a low priority.
The touring gear, I concluded that I wanted the lowest gear I could have that would give me a cadence of 72 while riding the slowest speed I could ride while maintaining vertical and directional stability. The cadence was selected as any slower and I fell that my pedal stroke is not very smooth, but 72 and higher feels like a smoother pedal stroke. While riding up the steepest hill nearby I concluded that the slowest speed where I maintained stability was 3.5 mph. So, a bit of calculations told me that I need a 36T chainring for touring. There have been some long shallow downhills where I missed not having higher gears, but I would not give up the lowest gears to obtain anything higher.
I am an engineer (now retired), have done a lot of technical spreadsheets over the years, thus the calculations to go from gear ratios or from a slow speed to determine chainring sizes was not that hard for me. But if you are a bit challenged by math, I can see where one of the on line gear calculators may help.
In my case with a 44 to 36 change, that is a difference of eight teeth, which becomes almost exactly four links on a chain. So, when I am using a 44T chainring, I have two quick links on my chain, with three links between them. Thus, I can remove one quick link and those other three links to quickly remove four links to change my chain length to accommodate the 36 chainring.
