Bickerton foldable mini-bike (photo)

On 5/5/2017 9:06 PM, Emanuel Berg wrote:
AMuzi wrote:

52x14 on a 20" is something around 6.1 meters
or 75 inches, a nice urban gearing.

You got the 75 inches like this?

echo $(( 52/14.0 * 20 ))
74.285714285714292

It seems tho that

$ units "$(( 52/14.0 * 20 )) inches" m
1.8868571

so ~1.9 meters?

And yes, to this bike's credit it DID feel good
pedaling, so mucking with the
sprocket/chainring sizes sure had the
desired effect!


We luddite English speakers use 'gear inches' which are the
equivalent of a highwheeler's outer diameter.

chainring/ sprocket * nominal wheel diameter in inches.

The metric countries use 'development' or meters traveled
per crank revolution.
chainring/ sprocket * (pi*2r) using metric radius.

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

AMuzi wrote:

gearing Since gear development is
chainring/ sprocket * wheel

Man, I'm certainly thankful I learned about
this! It feels like the bike got a whole new
dimension to it!

--
underground experts united
http://user.it.uu.se/~embe8573