Why do you think being able to see what rpm your riding in is so important?
I realize that transitioning from a bike with a tach to one without takes getting used to, but honestly, I don't think a tach is necessary for the vast majority of riding situations.
Seat of the pants feel is something you nurture and get very accustomed to over time.
Having the brick wall that is the rev limiter is a good thing to test once in a while as well.
Helps you get the feel for where you are in the rev range.
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2008 WR250X
Gearing: 13t - 48t
Power Commander 5 / PC-V
Airbox Door Removed - Flapper glued - AIS removed
FmF Q4
Bridgestone Battlax BT-003rs