Gearing

Chris did it really take maths for you to realise that shorter cranks increase gear inches if the ratio stays the same?? I knew that and I don't even know what the + sign means!!

As you obviously do, strange wizard man, can you tell me how many gear inches I'm running with 48x19, on a 23mm 700c tyre, with 170 mm cranks?

As hippy says gi stays the same, it just needs less force to turn longer cranks. same as using a longer handled spanner is easier to turn stubborn track nuts.
(622 + (2 x 23)) / 25.4 x (48 / 19) = 66.4"
(622 + (2 x 23)) / ( 170 x 2 ) x (48 / 19 ) = 4.96 gr

A higher gain ratio means its harder to pedal.