Quote Originally Posted by marfa View Post
Hey chaps
I've just counted the number the teeth I have 11-23.

What does that mean then?
I'll try a different way to explain this, bear with me:

Every time your back wheel rotates, you go forward about 2 meters or 6.5 feet.

When you are in the 11-tooth cog, the effort is divided by 11. So for every cog you go forward 7.5 inches or so.

If you are on the 23-tooth cog, the effort is divided by 23. So for every cog you go forward 3.5 inches or so.

Think of it as lifting weights: I can't lift 100 lbs. But I can lift a 10 lbs weight ten times.

Just the same way, if I'm going up a hill, I have a hard time moving forward 7.5 inch at a time in my 11-tooth cog. So I switch to an easier gear with more teeth (so a bigger cog) and I go forward, say, 4 inches at a time.

But if the hill is really steep, maybe 4 inch at a time is still too much. Maybe 3 inch at a time would be better. So I would need to have a 28-tooth cog at the back to be able to do that.

As someone else mentioned, you can get a cassette (a set of cogs) with more bigger cogs at the back. That will give you an easier time on steep hills. Think again of lifting weights: what you have currently is like the weights of a weightlifter (bike racer): lots of 20-25 lbs weights. If you're merely human like most of us you will probably appreciate 5-8-10 lbs weights. You'll find those on a 12-28.

[To understand this fully, you would have to take into account the chainring at the front. The chainring multiplies your effort at the back. But you just asked about 11-23 so I'll leave it at that.]