Saturday, 12 November 2011

Thinking about gears and gearing

I've been thinking about gears this week. I like the simplicity and function of my Sturmey-Archer 3-speed rear hub, but I wonder if I can improve it.
I am running a fairly soft set-up at the moment as regards gearing:
  • 1st gear = 38.5 inches
  • 2nd gear = 51.4 inches
  • 3rd gear = 68.5 inches.
I'm running a 44-tooth chainwheel, and an 16-tooth rear sprocket, with a 47-406 rear tyre.

I don't cycle very fast - a lot of the time I am on shared pedestrian/cyclist routes, so one always has to be considerate to other users. I got a speed reading yesterday using my smartphone (and the wonder of GPS technology) - I reached 20 mph (32 kph) downhill on a road section.
To be fair, I usually cycle at about 9 or 10 mph (14 to 16 kph) on the shared routes, and drop to half that when things get a bit busy. Sometimes I am down to 2 or 3 mph (3 to 5 kph) when there are a lot of folks about.

S, for the type of riding I do, I need relatively low gearing, but I seem to be able to ride at the lowest end without any real effort, so sometimes I fancy experimenting with moving the gears up a bit.

However, when there is a strong headwind and I am using the dynamo, the gearing seems quite high enough, thank you very much :-)
So I guess the folks who set up my bike knew what they were doing!