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Author Topic: MPH to RPM Ratio??  (Read 1009 times)

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Offline jt1000

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MPH to RPM Ratio??
« on: March 09, 2009, 09:55:38 AM »
Hey guys,

I feel like I've got my '72 cb500 pretty well lined out (except for an occasional clutch slip)  Just curious, on OEM sprockets, what's an apprx. rpm for 60mph?  Trying to dial in my speedo and tach and am trying to figure out if they are giving a decent reading....
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Jamil20

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Re: MPH to RPM Ratio??
« Reply #1 on: March 09, 2009, 10:37:25 AM »
In what gear?
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Offline jt1000

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Re: MPH to RPM Ratio??
« Reply #2 on: March 09, 2009, 10:46:57 AM »
Top Gear, 5th
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Online Kevin D

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Re: MPH to RPM Ratio??
« Reply #3 on: March 09, 2009, 05:07:24 PM »
This is for a 71 CB500.
From the graph at the bottom, looks like
4000 rpm = 50mph
6000 rpm = 75mph
8000 rpm = 100mph

also, from the table
mph/1000rpm in top gear....12.65

So 60/12.65 x 1000 = 4750rpm

and heres the whole article from the library:
http://www.sohc4.net/index.php?title=1971_Cycle_World_Road_Test
« Last Edit: March 09, 2009, 05:11:52 PM by Kevin D »
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71 CB750 K1
104,000 miles
Original Owner
———past———
70 SL100/125/150
70 Candy BlueGreen CB 750 K0
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Former Honda parts kid/counter kid/do all
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Whether you think you can or think you can’t, you’re right
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upperlake04

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Re: MPH to RPM Ratio??
« Reply #4 on: March 09, 2009, 06:07:58 PM »
  Member Wayne Grauel posted this revised gearing calculator spreadsheet some time back. You can plug in your numbers or possible sprocket changes to see the effect.
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