Re: digital tachometer
Far out man, you have typed a novel, and all of your steps and numbers are wrong, I have attached some spreadsheets (not my own) to show you the correct maths,
For a HT
Initial engine ratio is 4.1:1 20t drive, 82t driven
Secondary is usually 4.4:1 10t drive 44t driven
It equals around an 18:1 reduction ratio. I like an 16:1 ratio on my single speed bikes.
Normal 26" bike wheels are usually between 26 oto 27" high, the bare rims are around 23"
Measure it all up and a speedo is a tacho.
A stock 26" HT setup turns around 5800rpm at 25mph. Not 6959 or any other random number.
Last edited by wildemere; 05-03-2010 at 11:30 PM.