Quote:
Originally Posted by flyingeyepro
I assumed it's a hall effect sensor.

Someone else can confirm that?
Quote:
I'm getting pulses, but much past 10 mph and my speedo can't keep up with them.

I can't understand what you mean!
You havent any pulse above 10 mph, or your speedo do not display any higher speed than 10 mph?
Waht kind of aftermarket speedo are you using? I'm messing with a Veypor VR2.
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Help me out with the math
tire circumference = 79.5"
1 mile = 63360" = 797.16 tire revolutions per mile (trpm)
assuming 16/41 sprockets, 2.56 ratio
797.16 trpm = 2042.72 front sprocket revolutions per mile (fsrpm)

I'm not so skilled with imperial units, but your calculations seems quite right.
The only correction I have to do is that 63360/79.5 gives 796.98 not 797.16 trpm. According to this, fsrpm are 2040.27. To obtain pulses for mile you need , you have to multiply it for 27, the number of teeth that generates pulses. The requested value should be 55087.29.
I guess that you can approximate it to 55000 without any influence in accuracy.
Bye.