Gear sizes for a muppet

[DaddyPaddey]

I think I am being particularly stupid, but don't mind admitting it.

My new chariot has a 11/34 at the back with a Sram Dual Drive3, and the gearing seems a little higher than I expected.

I attacked the Sheldon Brown website which calculated the lowest gear as 21.9 inches, which is exactly the same as my Audax bike. This would be fine.

I understood that the gear inches were how far you went with one revolution of the pedals. I tried this on the chariot and it came out as 65" [and yes I did check with other bike which is about the same]. How have I lost the plot, and what am I doing wrong?

 

[Sharky]

All dates back to a penny-farthing, when the biggest gear you could have was the biggest wheel you could manage, so the convention was just based on wheel diameter.

Cheers Keith

 

[mjr]

[QUOTE 3974169, member: 9609"]It would have made so much more sense for gear inches to be gearing x circumference, but for reasons i don't understand it is gearing x diameter[/QUOTE]
Gearing x circumference is known as "development", isn't it?

 

[DaddyPaddey]

I undertood the bit about the penny farthings. So to get this straight, am I correct in thinking that gear inches do not state how far you have gone on one pedal revolution?

 

[PaulM]

Correct. Gear inches is the diameter of the wheel on your penny farthing.

 

[A.Z.KOETSIER]

I undertood the bit about the penny farthings. So to get this straight, am I correct in thinking that gear inches do not state how far you have gone on one pedal revolution?

What you are looking for is meters of development, see link below.

http://www.bikecalc.com/gear_meters_of_development

note you can always change meters to an imperial unit of your choice.

 

[DaddyPaddey]

I understand now-big thank you. I have always ridden with a high cadence so particularly liked a low gear on the Audax bike. As the new bent has the same 21.5" as the Audax lowest I assume the reason that I am finding it harder is that a) the bent is heavier, b)I can't stand up and c) I haven't yet fully got 'bent legs'

 

[stuee147]

@DaddyPaddey how have you found the sram duel drive hub iv been thinking of changing to it from a standard triple front with rear freewheel mainly to help clean up the chain line.

stuee

 

[DaddyPaddey]

absolutely 1st class. I have found it particularly useful when you are not certain which gear you want to be in, at a junction, to be able to drop into the lowest range whilst stationary. Something that usually happens at least once a ride when you don't realise you have stopped on a slight incline.

 

[stuee147]

thanks for that iv been looking at a few different setups the sram duel drive being the main one iv looked at but also the schlump drive combined with a shimano nexus rear hub. i love the cleaner chain lines and easier chain lines too but also the ability to change gear without moving and not forgetting the lower matinace on the whole thing