Technical > Transmission
Nomad Rohloff gearing
KDean:
What's the smallest gearing ratio you can have a a Nomad MK2 38---19?
mickeg:
If for a solo bike and if your weight is less than 100 kg, the ratio of 1.9 of chainring to sprocket.
See:
https://www.rohloff.de/en/experience/technology-in-detail/specifications
For touring, I am running a 36T chainring and 16T sprocket, ratio of 2.25.
But if you are a spinner and want a high cadence, you could certainly go down towards the 1.9.
If you weigh more than 100 kg, ratio is higher.
KDean:
I'm under 92kg , What the best for steep hills , Sorry I switched off looking at all these charts .
martinf:
For me, the best gear on hills is the lowest possible that still gives me a "reasonable" top gear.
I currently have 38 x 16 on my tourer, because that was the lowest permitted ratio when I bought the bike in 2012. I very rarely use the highest gear, so I will probably go to 38 x 19 at some stage.
38 x 19 gives a range of 14" to 74" with the 26" by 2" tyres I run. Top gear 74" at my preferred pedalling cadence of 90 rpm is 33 km/h, that speed will be OK for me on a loaded tourer, as I can only go that fast for any significant length of time on downhills or with a substantial tail wind.
I can still get the speed up to 43 km/h for a short period by increasing cadence to 120 rpm, for example if I need to integrate traffic on a big roundabout.
I have a 71" top gear on my 8-speed utility bike, and don't miss not having a higher gear on that.
As Mickeg says, it also depends on your pedalling style.
mickeg:
--- Quote from: KDean on October 12, 2021, 05:56:52 pm ---I'm under 92kg , What the best for steep hills , Sorry I switched off looking at all these charts .
--- End quote ---
I can't tell you what the best is for steep hills for you. Everyone is different.
I find the slowest I can ride and maintain horizontal and vertical stability is about 3.5 mph. And the slowest cadence I can run with it being smooth and not a pulsating slog is about 72 rpm.
So, after some calculations, with my 559X57mm tires I find that I need a 36T chainring and 16T sprocket to have a first gear that is about 3.5 mph with a cadence of 72. That is what I use for touring. I spin out on some shallow downhills but the steep uphill gearing is more important than shallow downhill gears.
But that is touring, with a heavy load of camping gear on the bike. When near home with an unladen bike, I switch to a 44T chainring instead, add four chain links. That way I have the lowest gears I need on an unladen bike and I have better downhill gearing for shallow downhills.
You likely will want something different, everyone is different.
Navigation
[0] Message Index
[#] Next page
Go to full version