atctim
03-18-2004, 12:01 PM
Can someone here please double check my math skills and comment:
Situation - I recently put 20" tires on the rear of my 1983 ATC200. Stockers are 25" - I had been running 22". Here's the deal - my top speed is way low now. I want this thing to fly on pavement. Don't care too much about power, as I have other trikes for that. Now for the math.
With stock sprockets (11 t front / 47 t rear) and 22" tires, I could get about 50 MPH out of the old girl. 47 divided by 11 = 4.27 front sprocket rotations per 1 back sprocket (thus tire) rotation.
22" tire = 69" circumfrence & 20" tire = 62.8" circ or about 9% difference thus a top speed of about 45MPH.
I believe that a 34 tooth rear sprocket is available for this trike. That would make 3.09 front sprockt rotations per one rear sprocket (thus tire) rotation. This is a 28% difference, thus boosting 45MPH 28% = 57.6 MPH.
Is this correct?? Also, I may go with a 12 tooth front sprocket instead of 11 for a top speed of 63MPH????? 11 tooth to 12 tooth boosts a 9% MPH increase.
Someone help please.
Thanks in advance.
ATCTIM
Situation - I recently put 20" tires on the rear of my 1983 ATC200. Stockers are 25" - I had been running 22". Here's the deal - my top speed is way low now. I want this thing to fly on pavement. Don't care too much about power, as I have other trikes for that. Now for the math.
With stock sprockets (11 t front / 47 t rear) and 22" tires, I could get about 50 MPH out of the old girl. 47 divided by 11 = 4.27 front sprocket rotations per 1 back sprocket (thus tire) rotation.
22" tire = 69" circumfrence & 20" tire = 62.8" circ or about 9% difference thus a top speed of about 45MPH.
I believe that a 34 tooth rear sprocket is available for this trike. That would make 3.09 front sprockt rotations per one rear sprocket (thus tire) rotation. This is a 28% difference, thus boosting 45MPH 28% = 57.6 MPH.
Is this correct?? Also, I may go with a 12 tooth front sprocket instead of 11 for a top speed of 63MPH????? 11 tooth to 12 tooth boosts a 9% MPH increase.
Someone help please.
Thanks in advance.
ATCTIM