View Single Post
  #9   Spotlight this post!  
Unread 08-04-2011, 16:48
Ether's Avatar
Ether Ether is offline
systems engineer (retired)
no team
 
Join Date: Nov 2009
Rookie Year: 1969
Location: US
Posts: 8,097
Ether has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond repute
Re: Dual CIM+CIMple box powered bike

Quote:
Originally Posted by Safety3rd View Post
i plan on using the sprocket that comes in the kit of parts ( 12 teeth) and the other gear has 28 teeth
Now we can do the math:

- The CIM's free speed is 5310 rpm

- The Cimple box steps that down 4.67:1 to 1137 rpm

- Your sprockets step that down 28:12 to 487 rpm

- In order to run the CIM continuous-duty without burning it up, you would want to run it at about maximum efficiency, which is 87.5% of free speed (1/5 horsepower). So 87.5% of 487 is 426 rpm

- 426 rpm is approximately 7 revs/second.

I don't think you normally pedal that fast.



Last edited by Ether : 08-04-2011 at 16:52.