Chain ring sizes? HARD to Pedal!

[Portland Rob]

Finally got one of my projects on the road....wow was it hard to pedal! I have a very large front chain ring. Can someone tell me the basics. Obviously I need a smaller one in front. How do I figure that out?

 

[aka_locojoe]

Or a bigger sprocket in the back if you're partial to the chainring that's on there now.

 

[udallcustombikes]

Ok, first off, I am not an expert nor did I stay at a Holidai Inn Express last night. That being said, here is my simple explanation.

Example: a 26" wheel's diameter is 26". To find the circumfrence multiply 26 by 3.14 (pi)= about 81 inches.

For ease of math we will say you are running a 45 tooth chain ring and a 15 tooth sprocket. So for each revolution of the crank there are three revolitions of the sprocket/wheel.
One crank revolution= 243" travel (81x3)

If you had a 60 tooth chain ring and the same 15 tooth sprocket it would be 4 revolutions of the wheel or 324".

If you keep the 45 CR and go to a 20 tooth sprocket you would get 2 1/4 wheel revs per crank rev or 182".

You have to pedal harder to travel further. If this is not correct, somebody better explain it to both of us.

 

[The LT]

Here is a link to an online gear calculator

http://software.bareknucklebrigade.com/ ... pplet.html

Sheldon brown has one on his page too.

 

[B607]

What do you have on there, a 52 tooth? They used those on boys bikes back in the 30's-50's when boys were men. :lol: If you want to keep the 52, find a 22 for the rear. That's about the best you can do. If that's not easy enough, put a 46 on the front with a 22 on the back...then the girls will be able to keep up with you. Gary

 

[udallcustombikes]

What do you have on there, a 52 tooth? They used those on boys bikes back in the 30's-50's when boys were men. :lol: If you want to keep the 52, find a 22 for the rear. That's about the best you can do. If that's not easy enough, put a 46 on the front with a 22 on the back...then the girls will be able to keep up with you. Gary

:lol: :lol: :lol:

 

[deorman]

46/18 is common gearing for 26" wheels, not too hard, nor dog-slow. A 49-52 front would take 20-22 for a similar ratio. Changing the rear ring could be easy or hard, depending on the age of your hub. For skip-tooth cogs, x's 1/2 those numbers obviously.

 

[stephen]

Divide the chainring by the sprocket, e.g. 46/18 is a 2.55 ratio, 38/14 is 2.71, 46/17 is 2.70 etc. You can write out loads of different ratios and keep it as a reference.

 

[spinman]

Every cruiser i have (3 now) has the same gear ratio; 44 up front and 22 in the rear. Seems perfect for the area i live.

Spin

 

[Dr. Tankenstein]

It's pretty hilly where I live, so I run a 36/18 combo. Pretty much the same as the 44/22 deal.