ZnsaneRyder
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- Local time
- 4:49 AM
- Joined
- Jun 19, 2008
- Messages
- 805
It would be nice to actually know what RPM's your engine is spinning to prevent overrevving it, or know if your belt, or friction drive is slipping, or to set your idle speed.
This was brought to my attention on a DIY go karting forum:
http://www.instructables.com/id/Tachometer-made-from-a-bicycle-speedometer-cycloc/
It says by entering the correct number into the bike computer, that it makes a good and simple tach. For Example, 2850RPM would read 28.5Mph.
*The only issue I see, is that they mount a magnet to a high speed shaft, which IMO is a bit risky if the magnet flys off, or it could cause some weight imbalance on a smaller High-RPM engine like a HappyTime.
Well, I'm planning on doing this, but use the white or yellow ignition wire to control a transistor to open and close the connection for the bike speedometer. I figure that the pulses on that wire would be a good indicator of RPM and would eliminate the magnet.
So, what do you folks here say about that? My goal is to make life easier for us bikers, and hopefully make our engines last longer, and a tach would do just that.
This was brought to my attention on a DIY go karting forum:
http://www.instructables.com/id/Tachometer-made-from-a-bicycle-speedometer-cycloc/
It says by entering the correct number into the bike computer, that it makes a good and simple tach. For Example, 2850RPM would read 28.5Mph.
Here is the calculation...
1 mph = 1.61 kph.
1.61 kph / 60 minutes in an hour = .026833 kilometers per minute
.026833 kpm* 1,000,000 millimeters per kilometer = 26,833 millimeters per minute
26,833 mmpm / 100 (scale factor) = 268 mm
*The only issue I see, is that they mount a magnet to a high speed shaft, which IMO is a bit risky if the magnet flys off, or it could cause some weight imbalance on a smaller High-RPM engine like a HappyTime.
Well, I'm planning on doing this, but use the white or yellow ignition wire to control a transistor to open and close the connection for the bike speedometer. I figure that the pulses on that wire would be a good indicator of RPM and would eliminate the magnet.
So, what do you folks here say about that? My goal is to make life easier for us bikers, and hopefully make our engines last longer, and a tach would do just that.